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Mucinous adenocarcinoma with signet ring cell features of the sublingual gland: A case report with an immunohistochemical analysis
Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology 30 (2018) 252–256
Contents lists available at ScienceDirect
Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology journal homepage: www.elsevier.com/locate/jomsmp
Case Report
Mucinous adenocarcinoma with signet ring cell features of the sublingual gland: A case report with an immunohistochemical analysis Masashi Nagata a,b,∗ , Kimihide Kusafuka c , Ryoji Yoshida a , Kenta Kawahara a , Yoshihiro Nakagawa a , Masafumi Nakamoto a , Masanori Shinohara a,d , Hideki Nakayama a a
Department of Oral & Maxillofacial Surgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan Department of Dentistry and Oral Surgery, Aso Iizuka Hospital, Fukuoka, Japan c Pathology Division, Shizuoka Cancer Center, Shizuoka, Japan d Ito Dento-Maxillofacial Hospital, Kumamoto, Japan b
a r t i c l e
i n f o
Article history: Received 16 May 2017 Received in revised form 16 December 2017 Accepted 25 December 2017 Available online 3 February 2018 Keywords: Mucinous adenocarcinoma Sublingual gland Signet ring cell feature Immunohistochemistry Poor prognosis
a b s t r a c t Mucinous adenocarcinoma (MAC) is a highly aggressive tumor, and its origin in the salivary glands is extremely rare. We report one case of salivary MAC showing highly invasive features with signet ring cells and immunohistochemical analysis. A 77-year-old Japanese woman who noticed painless swelling of the right floor of the mouth received surgical treatment and was diagnosed with primary MAC of the sublingual gland. The tumor consisted of two components: a glandular pattern and diffuse pattern with large mucinous lakes containing numerous signet ring cells. The tumor cells were immunopositive for CEA, CA125 and CK7 and strongly positive for Her-2 but negative for CK20, androgen receptor, GCDFP-15 and p63. The prognosis was poor, and the patient developed peritoneal metastasis and died. This case suggests that signet ring cell features in MAC may be a phenotype of aggression, and Her-2 may be a therapeutic target for MAC. Crown Copyright © 2017 Asian AOMS, ASOMP, JSOP, JSOMS, JSOM, and JAMI. Published by Elsevier Ltd. All rights reserved.夽
1. Introduction Mucinous adenocarcinoma (MAC) is an elusive tumor of the salivary glands because of its rarity and its diagnostic uncertainty. The most common localization is the large intestine (colon), and MAC has been shown to constitute 10%–20% of colorectal cancers, followed by the pancreas, ovary, lung, prostate and breast [1]. MAC of the head and neck is exceedingly rare and accounts for only about 3% of salivary gland tumors. Salivary gland MACs are characterized by high aggression due to a high rate of local recurrence and nodal metastasis [1,2]. The unifying pathologic description of MAC in the current standard textbooks is, “small clusters and single carcinoma cells floating in large pools of extracellular mucin compartmentalized by fibrous septa”. In addition, at least half of the tumor cells should produce
mucus [3]. Histologically, MAC may be similar to mucinous eccrine carcinoma of the skin, mucinous carcinoma of the breast and colloid carcinoma of the bowel [4]. An important feature of MAC is that the mucus-producing cells show positive staining on mucicarmine and Alcian blue staining. However, these cells are also characteristic for other salivary gland tumors. A definitive diagnosis of MAC as a primary salivary gland tumor is typically achieved by exclusion of metastatic disease. Due to these complexities associated with discrimination, immunohistochemical staining is helpful in the differential diagnosis. MAC is usually treated by surgery; however, a standard treatment has not been established due to its rarity. The role of chemotherapy and radiotherapy is controversial. The prognosis depends on the stage of the disease [5]. We herein report the clinicopathologic and immunohistochemical findings in a case of MAC occurring in the sublingual gland.
∗ Corresponding author at: Department of Oral & Maxillofacial Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto, 8608556, Japan. E-mail address: [email protected] (M. Nagata). https://doi.org/10.1016/j.ajoms.2017.12.008 2212-5558/Crown Copyright © 2017 Asian AOMS, ASOMP, JSOP, JSOMS, JSOM, and JAMI. Published by Elsevier Ltd. All rights reserved.夽
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Fig. 1. Intraoral photography and imaging examination findings. (A) The tumorous mass on the right side of the oral floor. (B) Positron emission tomography-computed tomography showing an irregular mass with an SUVmax of 7.6. (C,D) Magnetic resonance imaging showing an indistinct marginal mass with high intensity on T2-weighted imaging (yellow arrows).
2. Case report 2.1. Clinical findings A 77-year-old Japanese woman noted painless swelling of the right floor of the mouth from December 2012. On a physical examination, we noted a non-ulcer diffuse swelling in right oral floor (Fig. 1A). On palpation, a hard, elastic, thumb-sized mass was recognized. No regional lymph node swelling was noted. Computed tomography (CT) showed an irregular mass measuring 30 mm × 20 mm in the right sublingual gland, and positron emission tomography-computed tomography (PET-CT) showed that the SUVmax was 7.6 (Fig. 1B). Magnetic resonance imaging (MRI) showed high intensity in the region on short TI inversion recovery (STIR) imaging, suggesting invasion of the mylohyoid muscle (Fig. 1C and D). There is no distant metastasis and double cancer by image findings. An incisional biopsy was performed, and the histological diagnosis was “mucinous adenocarcinoma”. After the diagnosis, right sublingualectomy and selective submandibular neck dissection were performed (Fig. 2A; sublingualectomy specimen). No lymph node metastases were found histologically.
However, diffuse carcinoma cell invasion was observed around the submandibular gland. Fifteen months later, malaise and renal impairment was admitted and CT scan recognized peritoneal metastasis. A whole-body examination revealed no other primary malignant disease or local recurrence. Fine-needle aspiration cytology from ascites was performed, and the cytological finding was carcinoma cell, which had signet-ring cell features, and diagnosis was peritoneal carcinomatosis of MAC. After two months, she developed cachexia, and died. Autopsy was not permitted. 2.2. Pathological findings The gross specimen was a whitish or yellowish-white, circumscribed, 2.2 × 2.1 × 2.4-cm sized submucosal mass that was not encapsulated (Fig. 2B). Variably sized mucin lakes were loculated by fibrous septa and accounted for more than 50% of the total tumor area (Fig. 3A and B). Within the mucin pools, detached tumor cells floated individually and in small clumps, either solid or clustering around microlumina. Some individual cells manifested a signet ring cytomorphology but never showed dominance. The tumor cells were arranged in solid clusters and tended to form secondary
Fig. 2. Photograph of sublingualectomy and surgical specimen. (A) Right sublingualectomy and selective submandibular neck dissection were performed. (B) Macroscopically, the tumor was a whitish or yellowish-white, circumscribed, submucosal mass but not encapsulated.
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Fig. 3. Histological findings. (A) Growth of tumor cells on the fibrous stroma and mucus spreading was seen (original magnification 100×). (B) Clumps of carcinoma cells were surrounded by a sea of mucin (original magnification 200×). (C) Tumor cells showed a glandular pattern and diffused pattern (original magnification 100×). (D) The tumor area was adjacent to the normal lingual salivary glands (original magnification 200×). (E) Signet ring cells invaded around the submandibular glands (original magnification 40×). (F) Diffuse infiltration (mainly signet ring-shaped tumor cells) was seen into the muscular tissues (original magnification x200).
lumens or incomplete duct-like structures (Fig. 3C). In some views, the tumor nests were found to be adjacent to normal lingual salivary glands (Fig. 3D). Diffuse infiltration of the tumor cells with signet ring cell features into adipose, muscular, and neural periglandular tissues was evident (Fig. 3E and F). Neither tumor necrosis nor vascular invasion was apparent. Mitotic figures were infrequent. According to the cytologic grades of mucinous carcinoma of the skin [6], the tumor was Grade 3. The mucinous substance stained positively with mucicarmine and Alcian blue. 2.3. Immunohistochemical findings The immunohistochemical results using the antibodies in this study are summarized in Table 1. We performed the immunohistochemical examinations using EnVision (DakoCytomation, Cerointeria, CA, USA) and Autostainer (DakoCytomation) Almost all tumor cells showed strong immunoreactivity for epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA; Fig. 4A), CAM5.2 and CA125 (Fig. 4B). They were also positive for CK7 (Fig. 4C) but not for CK20 (Fig. 4D). The tumor cells were negative for alpha smooth muscle actin (␣SMA), S-100 protein, gross cystic disease fluid protein (GCDFP)-15 (Fig. 4E), vimentin and p63. Notably, all tumor cells showed strong positivity for Her2 (Fig. 4F). None of them expressed androgen receptor (Fig. 4G) or estrogen receptor (ER). The Ki-67 index was 15% (Fig. 4H). Regarding the mucin molecules, the signet ring cells were positive for MUC2 and partially positive for MUC1 but negative for MUC5AC and MUC6. The Supplementary figure shows the immunohistochemical findings for the mucin molecules. 3. Discussion MAC of the salivary gland is an extremely rare neoplasm. The actual frequency of MAC is unknown, but it comprises less than 0.1% of epithelial salivary gland tumors in the Armed Forces Institute of Pathology (AFIP) files [7]. The most frequently affected sites according to the World Health Organization (WHO) are the palate and the sublingual gland, followed by the submandibular gland and the upper lip; however, only one case in the sublingual gland, two
in the submandibular gland and one in the parotid gland have been reported. Mucinous adenocarcinoma of the salivary glands belongs to a high-grade category with a significant risk of local recurrence, lymph node metastasis and a fatal outcome. Peritoneal carcinomatosis (PM) as an initial distant metastasis from head and neck carcinoma is quite rare. Wakasaki et al. reported PM often results from cancers of peritoneal organs, and PM from head and neck carcinoma was quit rare [8]. Four reports described PM from head and neck cancer [9,10]. The present study appears to be the third reported case of PM occurring as an initial metastasis from head and neck cancer. Due to the highly invasive character and high-grade malignancy, postoperative radiotherapy was considerable. However, the patient refused radiotherapy, and the tumor peptide therapy as a clinical trial at our department was performed. Ide et al. report that the recommended treatment is complete surgical excision and the benefit of chemoradiotherapy as an adjunct remain empiric [2]. As with other rare tumors, a histopathological diagnosis can be difficult to obtain for MAC [2,3]. The WHO defines MAC as a malignant tumor composed of epithelial clusters with large pools of extracellular mucin. However, some authors argue that a mucinous appearance itself is not pathognomonic of MAC, and many salivary gland carcinomas may exhibit this trait. In this sense, the histologic diagnosis of MAC is usually obtained by exclusion. Histologically, mucinous adenocarcinoma is so characteristic that it rules out any other salivary gland carcinoma as a differential diagnostic possibility. In the histological typing of salivary gland tumors by the WHO, this tumor is described as a tumor in which cuboidal or columnar cells line mucus-filled lumens or cysts, and the mucus should occupy over 50% of the tumor without epidermoid or intermediate cells. The differential diagnostic considerations in the realm of MAC are cystadenocarcinoma [11], mucoepidermoid carcinoma [2], mucin-rich salivary duct carcinoma (mSDC) [12] and signet ring cell adenocarcinoma (srcAC) [13]. Gnepp et al. described that nuclear size in MAC as significantly smaller than mSDC [14]. Furthermore, mSDC is usually characterized by a mucinous area with floating cancer nests and an area with conventional salivary duct carcinomatous elements [15]. Cystadenocarcinoma has prominent
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Table 1 Antibodies used in this study and their examination results. Antigen
Clone
P/M
Source
Results
CK7 EMA CK20 LMWK Vimentin ASMA p63 S100 CEA CA125 Ki67 GCDFP15 HER2 AR ER MUC1 MUC2 MUC5ac MUC6
OV-TL 12/30 E29 Ks20.8 CAM5.2 V9 1A4 4A4
M M M M M M M P P M M M P M P M M M M
DakoCytomation (Carpinteria, CA, USA) DakoCytomation (Carpinteria, CA, USA) DakoCytomation (Carpinteria, CA, USA) Becton Dickinson (San Jose, CA, USA) DakoCytomation (Carpinteria, CA, USA) DakoCytomation (Carpinteria, CA, USA) LAB Vision (Fremont, CA, USA) Leica Biosystems(Nussloch, Germany) DakoCytomation (Carpinteria, CA, USA) DakoCytomation (Carpinteria, CA, USA) DakoCytomation (Carpinteria, CA, USA) Novocastra Laboratories (Newcastle upon Tyne, UK) Roche Diagnostics (Indianapolis, IN, USA) DakoCytomation (Carpinteria, CA, USA) Roche Diagnostics (Indianapolis, IN, USA) Leica Biosystems(Nussloch, Germany) Leica Biosystems(Nussloch, Germany) Leica Biosystems(Nussloch, Germany) Leica Biosystems(Nussloch, Germany)
Weak positive Strong positive Negative Strong positive Negative Negative Negative Negative Strong positive Strong positive 15% Negative Strong positive Negative Negative Weak positive Strong positive Negative Negative
II-7 M11 MIB-1 NCL-GCDFP-15 AR441 SP-1 Ma695 Ccp58 CLH2 CLH5
CK, cytokeratin; EMA, epithelial membrane antigen; SMA, smooth muscle actin; CEA, carcinoembryonic antigen; CA, carbohydrate antigen; GCDFP, gross cystic disease fluid protein; AR, androgen receptor; ER, estrogen receptor; MUC, mucin.
Fig. 4. Immunohistochemical findings (original magnification 400×). The tumor cells in MAC were strongly positive for CEA (A), CA125 (B) and CK7 (C) and negative for CK20 (D). (E) The tumor cells in MAC were negative for gross cystic fluid disease protein-15 (only normal salivary glands are positive). (F) They were also strongly positive for Her-2. (G) The tumor cells were negative for androgen receptor. (H) The nuclear signals for Ki-67 were seen in tumor cells in MAC. The Ki-67 labeling index was 15%.
cystic spaces with malignant epithelial lining. Mucoepidermoid carcinoma has typical areas of squamous, intermediate and mucinsecreting cells. In our case, these cells were not recognized, and some signet ring cells were observed at the invasive front of the tumor. However, some salivary gland tumors also exhibit signet ring cells, and srcAC does not typically have polygonal or cuboidal eosinophilic cells [14]. The quantity of mucinous components in other tumors is not as extensive as in MAC. An important feature of MAC is the presence of mucus-producing cells with positive staining for mucicarmine and Alcian blue staining. However, these cells are also characteristic of other salivary gland tumors. In our case, we recognized continuity between the tumor region and the sublingual gland; therefore, the lesion was considered a primary sublingual tumor. However, a definitive diagnosis of MAC as a primary salivary gland tumor is achieved by exclusion of metastatic disease; therefore, immunohistochemical (IHC) staining was helpful in the differential diagnosis. The immunotyping of CK7/CK20 may aid in substantiating the tumor origin. The CK7(+)/CK20(−) phenotype may indicate a salivary primary site [2]. In this case, the tumor showed expression for CK7 but not for CK20, suggesting a primary MAC. The typical findings for MAC are a strongly positive reaction for AE1/AE3 and CK7; an intermediate or strong reaction for CK8, CK18 and CK19; a
positive reaction for EMA, vimentin and CEA; and a varied reaction for ␣-SMA, ␣-amylase and calcitonin. mSDC cells are usually positive for androgen receptor and GCDFP-15. In comparison with MAC, some author have reported that srcAC was positive for p63 and ␣SMA in addition to several epithelial markers. Our case showed strong positive staining for Her-2 and some epithelial cell markers. The tumor cells were negative for all myoepithelial markers, such as ␣SMA, calponin, CK14 and p63, as well as S-100 protein and GCDFP-15. Furthermore, the cells showed no pleomorphic adenoma components and no double tubular layer like SDC. We finally diagnosed the patient with primary MAC of the sublingual gland. To our knowledge, no comprehensive study has addressed the usefulness of mucin markers in salivary tumors, and the available information on mucin expression in normal salivary glands themselves is also limited. A study on MUC1 and MUC2 in the normal gland and some tumors has recently been reported in abstract form but did not include any cases of MAC. Alos et al. reported a mucin antigen profile in salivary mucoepidermoid carcinoma and suggested that high MUC1 and low MUC4 expression were characteristics of poor differentiation and aggressive behavior [16,17]. Although a few previous reports have described the mucin profile of salivary gland tumors [16], the mucin expression pattern in MAC is now under investigation.
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It has been reported that the immunohistochemical expression of Ki-67 is associated with poor prognosis in many salivary gland tumors. Ide et al. [2] found an average Ki-67 index of 38% in MAC. A high Ki-67 index (>30%) has been found to correlate well with a poor overall survival in salivary carcinomas [18]. In our case, in addition to a low Ki-67 index, she had a poor prognosis. Kusafuka et al. reported a rare case of mSDC with predominantly signet ring cell features ex PA; elevated numbers of signet ring cells in mSDC are associated with aggressive behavior[17]. In our case, the invasive front and peritoneal metastasis sites were found to have interspersed signet ring cells. This characteristic may suggest aggressive behavior of salivary gland carcinoma. Furthermore, our case showed high Her-2 expression in the tumor cells, which may be useful as a target molecule, potentially representing a new strategy for curing salivary MAC. Ethical approval Ethics approval was given by Kumamoto University Ethics Committee. Disclosure of potential conflicts of interest None of the authors has any potential conflicts of interest to declare. Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at https://doi.org/10.1016/j.ajoms.2017.12.008. References [1] Uchida K, Oga A, Mano T, Nagatsuka H, Ueyama Y, Sasaki K. Screening for DNA copy number aberrations in mucinous adenocarcinoma arising from the minor salivary gland: two case reports. Cancer Genet Cytogenet 2010;203:324–7. [2] Ide F, Mishima K, Tanaka A, Saito I, Kusama K. Mucinous adenocarcinoma of minor salivary glands: a high-grade malignancy prone to lymph node metastasis. Virchows Arch 2009;454:55–60. [3] Hashitani S, Sakurai K, Noguchi K, Natori J, Urade M. Mucinous adenocarcinoma with neuroendocrine differentiation of the mandibular ramus: report of a case. J Oral Pathol Med 2004;33:59–63.
[4] Notani K, Iizuka T, Yamazaki Y, Henmi T, Sugiura C, Kohgo T, et al. Mucinous adenocarcinoma of probable minor salivary gland origin. Oral Surg, Oral Med, Oral Pathol, Oral Radiol, Endodontics 2002;94:738–40. [5] Guimaraes KB, Gordon MA. Mucinous adenocarcinoma of minor salivary gland: case report and literature review. J Clinic Case Rep 2012;2:1–4. [6] Kazakov DV, Suster S, LeBoit PE, Calonje E, Bisceglia M, Kutzner H, et al. Mucinous carcinoma of the skin, primary, and secondary: a clinicopathologic study of 63 cases with emphasis on the morphologic spectrum of primary cutaneous forms: homologies with mucinous lesions in the breast. Am J Surg Pathol 2005;29:764–82. [7] Ellis GL. Tumors of the salivary glands. 4th edn Washington DC: American Registry of Pathology and Armed Forces Institute of Pathology; 2008. [8] Wakasaki T, Omori H, Sueyoshi S, Rikimaru F, Toh S, Taguchi K, et al. A case of peritoneal metastasis during treatment for hypopharyngeal squamous cell carcinoma. World J Surg Oncol 2016;14:265. [9] Wong ZW, Leong SS, Tan T, Mancer K. A case of metastatic squamous cell carcinoma of the hypopharynx manifesting as acute abdomen. Ann Acad Med Singapore 2004;33:356–8. [10] Hsu CL, Wang HM, Lee CS, Liao CT, Chen TC. Hypopharyngeal carcinoma with clinical peritoneal carcinomatosis: a report of two patients. Am J Clin Oncol 1998;21:362–5. [11] Foss RD, Ellis GL, Auclair PL. Salivary gland cystadenocarcinomas: a clinicopathologic study of 57 cases. Am J Surg Pathol 1996;20:1440–7. [12] Henley J, Summerlin DJ, Potter D, Tomich C. Intraoral mucin-rich salivary duct carcinoma. Histopathology 2005;47:436–7. [13] Ghannoum JE, Freedman PD. Signet-ring cell (mucin-producing) adenocarcinomas of minor salivary glands. Am J Surg Pathol 2004;28:89–93. [14] Gnepp DR. Salivary gland tumor wishes to add to the next WHO Tumor Classification: sclerosing polycystic adenosis, mammary analogue secretory carcinoma, cribriform adenocarcinoma of the tongue and other sites, and mucinous variant of myoepithelioma. Head Neck Pathol 2014;8:42–9. [15] Brandwein-Gensler MS, Nagao T. Salivary duct carcinoma. In: Barnes LEJ, Reichart P, Sidransky D, editors. World Health Organization classification of the tumours: pathology and genetics of head and neck tumours. Lyon: IARC press; 2005. [16] Kusafuka K, Nakamura S, Asano R, Kamijo T, Iida Y, Onistuka T, et al. Osteoclast-type giant cell tumor of minor salivary gland with mucin-rich salivary duct carcinoma: a case report of unusual histology with immunohistochemical analysis. Oral Surg, Oral Med, Oral Pathol, Oral Radiol, Endodontics 2010;109:870–7. [17] Kusafuka K, Maeda M, Honda M, Nakajima T. Mucin-rich salivary duct carcinoma with signet-ring cell feature ex pleomorphic adenoma of the submandibular gland: a case report of an unusual histology with immunohistochemical analysis and review of the literature. Med Mol Morphol 2012;45:45–52. [18] Cheuk W, Chan JK. Advances in salivary gland pathology. Histopathology 2007;51:1–20.
Contents lists available at ScienceDirect
Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology journal homepage: www.elsevier.com/locate/jomsmp
Case Report
Mucinous adenocarcinoma with signet ring cell features of the sublingual gland: A case report with an immunohistochemical analysis Masashi Nagata a,b,∗ , Kimihide Kusafuka c , Ryoji Yoshida a , Kenta Kawahara a , Yoshihiro Nakagawa a , Masafumi Nakamoto a , Masanori Shinohara a,d , Hideki Nakayama a a
Department of Oral & Maxillofacial Surgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan Department of Dentistry and Oral Surgery, Aso Iizuka Hospital, Fukuoka, Japan c Pathology Division, Shizuoka Cancer Center, Shizuoka, Japan d Ito Dento-Maxillofacial Hospital, Kumamoto, Japan b
a r t i c l e
i n f o
Article history: Received 16 May 2017 Received in revised form 16 December 2017 Accepted 25 December 2017 Available online 3 February 2018 Keywords: Mucinous adenocarcinoma Sublingual gland Signet ring cell feature Immunohistochemistry Poor prognosis
a b s t r a c t Mucinous adenocarcinoma (MAC) is a highly aggressive tumor, and its origin in the salivary glands is extremely rare. We report one case of salivary MAC showing highly invasive features with signet ring cells and immunohistochemical analysis. A 77-year-old Japanese woman who noticed painless swelling of the right floor of the mouth received surgical treatment and was diagnosed with primary MAC of the sublingual gland. The tumor consisted of two components: a glandular pattern and diffuse pattern with large mucinous lakes containing numerous signet ring cells. The tumor cells were immunopositive for CEA, CA125 and CK7 and strongly positive for Her-2 but negative for CK20, androgen receptor, GCDFP-15 and p63. The prognosis was poor, and the patient developed peritoneal metastasis and died. This case suggests that signet ring cell features in MAC may be a phenotype of aggression, and Her-2 may be a therapeutic target for MAC. Crown Copyright © 2017 Asian AOMS, ASOMP, JSOP, JSOMS, JSOM, and JAMI. Published by Elsevier Ltd. All rights reserved.夽
1. Introduction Mucinous adenocarcinoma (MAC) is an elusive tumor of the salivary glands because of its rarity and its diagnostic uncertainty. The most common localization is the large intestine (colon), and MAC has been shown to constitute 10%–20% of colorectal cancers, followed by the pancreas, ovary, lung, prostate and breast [1]. MAC of the head and neck is exceedingly rare and accounts for only about 3% of salivary gland tumors. Salivary gland MACs are characterized by high aggression due to a high rate of local recurrence and nodal metastasis [1,2]. The unifying pathologic description of MAC in the current standard textbooks is, “small clusters and single carcinoma cells floating in large pools of extracellular mucin compartmentalized by fibrous septa”. In addition, at least half of the tumor cells should produce
mucus [3]. Histologically, MAC may be similar to mucinous eccrine carcinoma of the skin, mucinous carcinoma of the breast and colloid carcinoma of the bowel [4]. An important feature of MAC is that the mucus-producing cells show positive staining on mucicarmine and Alcian blue staining. However, these cells are also characteristic for other salivary gland tumors. A definitive diagnosis of MAC as a primary salivary gland tumor is typically achieved by exclusion of metastatic disease. Due to these complexities associated with discrimination, immunohistochemical staining is helpful in the differential diagnosis. MAC is usually treated by surgery; however, a standard treatment has not been established due to its rarity. The role of chemotherapy and radiotherapy is controversial. The prognosis depends on the stage of the disease [5]. We herein report the clinicopathologic and immunohistochemical findings in a case of MAC occurring in the sublingual gland.
∗ Corresponding author at: Department of Oral & Maxillofacial Surgery, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto, 8608556, Japan. E-mail address: [email protected] (M. Nagata). https://doi.org/10.1016/j.ajoms.2017.12.008 2212-5558/Crown Copyright © 2017 Asian AOMS, ASOMP, JSOP, JSOMS, JSOM, and JAMI. Published by Elsevier Ltd. All rights reserved.夽
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Fig. 1. Intraoral photography and imaging examination findings. (A) The tumorous mass on the right side of the oral floor. (B) Positron emission tomography-computed tomography showing an irregular mass with an SUVmax of 7.6. (C,D) Magnetic resonance imaging showing an indistinct marginal mass with high intensity on T2-weighted imaging (yellow arrows).
2. Case report 2.1. Clinical findings A 77-year-old Japanese woman noted painless swelling of the right floor of the mouth from December 2012. On a physical examination, we noted a non-ulcer diffuse swelling in right oral floor (Fig. 1A). On palpation, a hard, elastic, thumb-sized mass was recognized. No regional lymph node swelling was noted. Computed tomography (CT) showed an irregular mass measuring 30 mm × 20 mm in the right sublingual gland, and positron emission tomography-computed tomography (PET-CT) showed that the SUVmax was 7.6 (Fig. 1B). Magnetic resonance imaging (MRI) showed high intensity in the region on short TI inversion recovery (STIR) imaging, suggesting invasion of the mylohyoid muscle (Fig. 1C and D). There is no distant metastasis and double cancer by image findings. An incisional biopsy was performed, and the histological diagnosis was “mucinous adenocarcinoma”. After the diagnosis, right sublingualectomy and selective submandibular neck dissection were performed (Fig. 2A; sublingualectomy specimen). No lymph node metastases were found histologically.
However, diffuse carcinoma cell invasion was observed around the submandibular gland. Fifteen months later, malaise and renal impairment was admitted and CT scan recognized peritoneal metastasis. A whole-body examination revealed no other primary malignant disease or local recurrence. Fine-needle aspiration cytology from ascites was performed, and the cytological finding was carcinoma cell, which had signet-ring cell features, and diagnosis was peritoneal carcinomatosis of MAC. After two months, she developed cachexia, and died. Autopsy was not permitted. 2.2. Pathological findings The gross specimen was a whitish or yellowish-white, circumscribed, 2.2 × 2.1 × 2.4-cm sized submucosal mass that was not encapsulated (Fig. 2B). Variably sized mucin lakes were loculated by fibrous septa and accounted for more than 50% of the total tumor area (Fig. 3A and B). Within the mucin pools, detached tumor cells floated individually and in small clumps, either solid or clustering around microlumina. Some individual cells manifested a signet ring cytomorphology but never showed dominance. The tumor cells were arranged in solid clusters and tended to form secondary
Fig. 2. Photograph of sublingualectomy and surgical specimen. (A) Right sublingualectomy and selective submandibular neck dissection were performed. (B) Macroscopically, the tumor was a whitish or yellowish-white, circumscribed, submucosal mass but not encapsulated.
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Fig. 3. Histological findings. (A) Growth of tumor cells on the fibrous stroma and mucus spreading was seen (original magnification 100×). (B) Clumps of carcinoma cells were surrounded by a sea of mucin (original magnification 200×). (C) Tumor cells showed a glandular pattern and diffused pattern (original magnification 100×). (D) The tumor area was adjacent to the normal lingual salivary glands (original magnification 200×). (E) Signet ring cells invaded around the submandibular glands (original magnification 40×). (F) Diffuse infiltration (mainly signet ring-shaped tumor cells) was seen into the muscular tissues (original magnification x200).
lumens or incomplete duct-like structures (Fig. 3C). In some views, the tumor nests were found to be adjacent to normal lingual salivary glands (Fig. 3D). Diffuse infiltration of the tumor cells with signet ring cell features into adipose, muscular, and neural periglandular tissues was evident (Fig. 3E and F). Neither tumor necrosis nor vascular invasion was apparent. Mitotic figures were infrequent. According to the cytologic grades of mucinous carcinoma of the skin [6], the tumor was Grade 3. The mucinous substance stained positively with mucicarmine and Alcian blue. 2.3. Immunohistochemical findings The immunohistochemical results using the antibodies in this study are summarized in Table 1. We performed the immunohistochemical examinations using EnVision (DakoCytomation, Cerointeria, CA, USA) and Autostainer (DakoCytomation) Almost all tumor cells showed strong immunoreactivity for epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA; Fig. 4A), CAM5.2 and CA125 (Fig. 4B). They were also positive for CK7 (Fig. 4C) but not for CK20 (Fig. 4D). The tumor cells were negative for alpha smooth muscle actin (␣SMA), S-100 protein, gross cystic disease fluid protein (GCDFP)-15 (Fig. 4E), vimentin and p63. Notably, all tumor cells showed strong positivity for Her2 (Fig. 4F). None of them expressed androgen receptor (Fig. 4G) or estrogen receptor (ER). The Ki-67 index was 15% (Fig. 4H). Regarding the mucin molecules, the signet ring cells were positive for MUC2 and partially positive for MUC1 but negative for MUC5AC and MUC6. The Supplementary figure shows the immunohistochemical findings for the mucin molecules. 3. Discussion MAC of the salivary gland is an extremely rare neoplasm. The actual frequency of MAC is unknown, but it comprises less than 0.1% of epithelial salivary gland tumors in the Armed Forces Institute of Pathology (AFIP) files [7]. The most frequently affected sites according to the World Health Organization (WHO) are the palate and the sublingual gland, followed by the submandibular gland and the upper lip; however, only one case in the sublingual gland, two
in the submandibular gland and one in the parotid gland have been reported. Mucinous adenocarcinoma of the salivary glands belongs to a high-grade category with a significant risk of local recurrence, lymph node metastasis and a fatal outcome. Peritoneal carcinomatosis (PM) as an initial distant metastasis from head and neck carcinoma is quite rare. Wakasaki et al. reported PM often results from cancers of peritoneal organs, and PM from head and neck carcinoma was quit rare [8]. Four reports described PM from head and neck cancer [9,10]. The present study appears to be the third reported case of PM occurring as an initial metastasis from head and neck cancer. Due to the highly invasive character and high-grade malignancy, postoperative radiotherapy was considerable. However, the patient refused radiotherapy, and the tumor peptide therapy as a clinical trial at our department was performed. Ide et al. report that the recommended treatment is complete surgical excision and the benefit of chemoradiotherapy as an adjunct remain empiric [2]. As with other rare tumors, a histopathological diagnosis can be difficult to obtain for MAC [2,3]. The WHO defines MAC as a malignant tumor composed of epithelial clusters with large pools of extracellular mucin. However, some authors argue that a mucinous appearance itself is not pathognomonic of MAC, and many salivary gland carcinomas may exhibit this trait. In this sense, the histologic diagnosis of MAC is usually obtained by exclusion. Histologically, mucinous adenocarcinoma is so characteristic that it rules out any other salivary gland carcinoma as a differential diagnostic possibility. In the histological typing of salivary gland tumors by the WHO, this tumor is described as a tumor in which cuboidal or columnar cells line mucus-filled lumens or cysts, and the mucus should occupy over 50% of the tumor without epidermoid or intermediate cells. The differential diagnostic considerations in the realm of MAC are cystadenocarcinoma [11], mucoepidermoid carcinoma [2], mucin-rich salivary duct carcinoma (mSDC) [12] and signet ring cell adenocarcinoma (srcAC) [13]. Gnepp et al. described that nuclear size in MAC as significantly smaller than mSDC [14]. Furthermore, mSDC is usually characterized by a mucinous area with floating cancer nests and an area with conventional salivary duct carcinomatous elements [15]. Cystadenocarcinoma has prominent
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Table 1 Antibodies used in this study and their examination results. Antigen
Clone
P/M
Source
Results
CK7 EMA CK20 LMWK Vimentin ASMA p63 S100 CEA CA125 Ki67 GCDFP15 HER2 AR ER MUC1 MUC2 MUC5ac MUC6
OV-TL 12/30 E29 Ks20.8 CAM5.2 V9 1A4 4A4
M M M M M M M P P M M M P M P M M M M
DakoCytomation (Carpinteria, CA, USA) DakoCytomation (Carpinteria, CA, USA) DakoCytomation (Carpinteria, CA, USA) Becton Dickinson (San Jose, CA, USA) DakoCytomation (Carpinteria, CA, USA) DakoCytomation (Carpinteria, CA, USA) LAB Vision (Fremont, CA, USA) Leica Biosystems(Nussloch, Germany) DakoCytomation (Carpinteria, CA, USA) DakoCytomation (Carpinteria, CA, USA) DakoCytomation (Carpinteria, CA, USA) Novocastra Laboratories (Newcastle upon Tyne, UK) Roche Diagnostics (Indianapolis, IN, USA) DakoCytomation (Carpinteria, CA, USA) Roche Diagnostics (Indianapolis, IN, USA) Leica Biosystems(Nussloch, Germany) Leica Biosystems(Nussloch, Germany) Leica Biosystems(Nussloch, Germany) Leica Biosystems(Nussloch, Germany)
Weak positive Strong positive Negative Strong positive Negative Negative Negative Negative Strong positive Strong positive 15% Negative Strong positive Negative Negative Weak positive Strong positive Negative Negative
II-7 M11 MIB-1 NCL-GCDFP-15 AR441 SP-1 Ma695 Ccp58 CLH2 CLH5
CK, cytokeratin; EMA, epithelial membrane antigen; SMA, smooth muscle actin; CEA, carcinoembryonic antigen; CA, carbohydrate antigen; GCDFP, gross cystic disease fluid protein; AR, androgen receptor; ER, estrogen receptor; MUC, mucin.
Fig. 4. Immunohistochemical findings (original magnification 400×). The tumor cells in MAC were strongly positive for CEA (A), CA125 (B) and CK7 (C) and negative for CK20 (D). (E) The tumor cells in MAC were negative for gross cystic fluid disease protein-15 (only normal salivary glands are positive). (F) They were also strongly positive for Her-2. (G) The tumor cells were negative for androgen receptor. (H) The nuclear signals for Ki-67 were seen in tumor cells in MAC. The Ki-67 labeling index was 15%.
cystic spaces with malignant epithelial lining. Mucoepidermoid carcinoma has typical areas of squamous, intermediate and mucinsecreting cells. In our case, these cells were not recognized, and some signet ring cells were observed at the invasive front of the tumor. However, some salivary gland tumors also exhibit signet ring cells, and srcAC does not typically have polygonal or cuboidal eosinophilic cells [14]. The quantity of mucinous components in other tumors is not as extensive as in MAC. An important feature of MAC is the presence of mucus-producing cells with positive staining for mucicarmine and Alcian blue staining. However, these cells are also characteristic of other salivary gland tumors. In our case, we recognized continuity between the tumor region and the sublingual gland; therefore, the lesion was considered a primary sublingual tumor. However, a definitive diagnosis of MAC as a primary salivary gland tumor is achieved by exclusion of metastatic disease; therefore, immunohistochemical (IHC) staining was helpful in the differential diagnosis. The immunotyping of CK7/CK20 may aid in substantiating the tumor origin. The CK7(+)/CK20(−) phenotype may indicate a salivary primary site [2]. In this case, the tumor showed expression for CK7 but not for CK20, suggesting a primary MAC. The typical findings for MAC are a strongly positive reaction for AE1/AE3 and CK7; an intermediate or strong reaction for CK8, CK18 and CK19; a
positive reaction for EMA, vimentin and CEA; and a varied reaction for ␣-SMA, ␣-amylase and calcitonin. mSDC cells are usually positive for androgen receptor and GCDFP-15. In comparison with MAC, some author have reported that srcAC was positive for p63 and ␣SMA in addition to several epithelial markers. Our case showed strong positive staining for Her-2 and some epithelial cell markers. The tumor cells were negative for all myoepithelial markers, such as ␣SMA, calponin, CK14 and p63, as well as S-100 protein and GCDFP-15. Furthermore, the cells showed no pleomorphic adenoma components and no double tubular layer like SDC. We finally diagnosed the patient with primary MAC of the sublingual gland. To our knowledge, no comprehensive study has addressed the usefulness of mucin markers in salivary tumors, and the available information on mucin expression in normal salivary glands themselves is also limited. A study on MUC1 and MUC2 in the normal gland and some tumors has recently been reported in abstract form but did not include any cases of MAC. Alos et al. reported a mucin antigen profile in salivary mucoepidermoid carcinoma and suggested that high MUC1 and low MUC4 expression were characteristics of poor differentiation and aggressive behavior [16,17]. Although a few previous reports have described the mucin profile of salivary gland tumors [16], the mucin expression pattern in MAC is now under investigation.
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It has been reported that the immunohistochemical expression of Ki-67 is associated with poor prognosis in many salivary gland tumors. Ide et al. [2] found an average Ki-67 index of 38% in MAC. A high Ki-67 index (>30%) has been found to correlate well with a poor overall survival in salivary carcinomas [18]. In our case, in addition to a low Ki-67 index, she had a poor prognosis. Kusafuka et al. reported a rare case of mSDC with predominantly signet ring cell features ex PA; elevated numbers of signet ring cells in mSDC are associated with aggressive behavior[17]. In our case, the invasive front and peritoneal metastasis sites were found to have interspersed signet ring cells. This characteristic may suggest aggressive behavior of salivary gland carcinoma. Furthermore, our case showed high Her-2 expression in the tumor cells, which may be useful as a target molecule, potentially representing a new strategy for curing salivary MAC. Ethical approval Ethics approval was given by Kumamoto University Ethics Committee. Disclosure of potential conflicts of interest None of the authors has any potential conflicts of interest to declare. Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at https://doi.org/10.1016/j.ajoms.2017.12.008. References [1] Uchida K, Oga A, Mano T, Nagatsuka H, Ueyama Y, Sasaki K. Screening for DNA copy number aberrations in mucinous adenocarcinoma arising from the minor salivary gland: two case reports. Cancer Genet Cytogenet 2010;203:324–7. [2] Ide F, Mishima K, Tanaka A, Saito I, Kusama K. Mucinous adenocarcinoma of minor salivary glands: a high-grade malignancy prone to lymph node metastasis. Virchows Arch 2009;454:55–60. [3] Hashitani S, Sakurai K, Noguchi K, Natori J, Urade M. Mucinous adenocarcinoma with neuroendocrine differentiation of the mandibular ramus: report of a case. J Oral Pathol Med 2004;33:59–63.
[4] Notani K, Iizuka T, Yamazaki Y, Henmi T, Sugiura C, Kohgo T, et al. Mucinous adenocarcinoma of probable minor salivary gland origin. Oral Surg, Oral Med, Oral Pathol, Oral Radiol, Endodontics 2002;94:738–40. [5] Guimaraes KB, Gordon MA. Mucinous adenocarcinoma of minor salivary gland: case report and literature review. J Clinic Case Rep 2012;2:1–4. [6] Kazakov DV, Suster S, LeBoit PE, Calonje E, Bisceglia M, Kutzner H, et al. Mucinous carcinoma of the skin, primary, and secondary: a clinicopathologic study of 63 cases with emphasis on the morphologic spectrum of primary cutaneous forms: homologies with mucinous lesions in the breast. Am J Surg Pathol 2005;29:764–82. [7] Ellis GL. Tumors of the salivary glands. 4th edn Washington DC: American Registry of Pathology and Armed Forces Institute of Pathology; 2008. [8] Wakasaki T, Omori H, Sueyoshi S, Rikimaru F, Toh S, Taguchi K, et al. A case of peritoneal metastasis during treatment for hypopharyngeal squamous cell carcinoma. World J Surg Oncol 2016;14:265. [9] Wong ZW, Leong SS, Tan T, Mancer K. A case of metastatic squamous cell carcinoma of the hypopharynx manifesting as acute abdomen. Ann Acad Med Singapore 2004;33:356–8. [10] Hsu CL, Wang HM, Lee CS, Liao CT, Chen TC. Hypopharyngeal carcinoma with clinical peritoneal carcinomatosis: a report of two patients. Am J Clin Oncol 1998;21:362–5. [11] Foss RD, Ellis GL, Auclair PL. Salivary gland cystadenocarcinomas: a clinicopathologic study of 57 cases. Am J Surg Pathol 1996;20:1440–7. [12] Henley J, Summerlin DJ, Potter D, Tomich C. Intraoral mucin-rich salivary duct carcinoma. Histopathology 2005;47:436–7. [13] Ghannoum JE, Freedman PD. Signet-ring cell (mucin-producing) adenocarcinomas of minor salivary glands. Am J Surg Pathol 2004;28:89–93. [14] Gnepp DR. Salivary gland tumor wishes to add to the next WHO Tumor Classification: sclerosing polycystic adenosis, mammary analogue secretory carcinoma, cribriform adenocarcinoma of the tongue and other sites, and mucinous variant of myoepithelioma. Head Neck Pathol 2014;8:42–9. [15] Brandwein-Gensler MS, Nagao T. Salivary duct carcinoma. In: Barnes LEJ, Reichart P, Sidransky D, editors. World Health Organization classification of the tumours: pathology and genetics of head and neck tumours. Lyon: IARC press; 2005. [16] Kusafuka K, Nakamura S, Asano R, Kamijo T, Iida Y, Onistuka T, et al. Osteoclast-type giant cell tumor of minor salivary gland with mucin-rich salivary duct carcinoma: a case report of unusual histology with immunohistochemical analysis. Oral Surg, Oral Med, Oral Pathol, Oral Radiol, Endodontics 2010;109:870–7. [17] Kusafuka K, Maeda M, Honda M, Nakajima T. Mucin-rich salivary duct carcinoma with signet-ring cell feature ex pleomorphic adenoma of the submandibular gland: a case report of an unusual histology with immunohistochemical analysis and review of the literature. Med Mol Morphol 2012;45:45–52. [18] Cheuk W, Chan JK. Advances in salivary gland pathology. Histopathology 2007;51:1–20.