- Email: [email protected]
Adult rhabdomyoma of the tongue in a child
CORRESPONDENCE
2. Marshall JL, Haller DG, de Gramont A, et al. Adjuvant therapy for stage II and III colon cancer: consensus report of the International Society of Gastrointestinal Oncology. Gastrointest Cancer Res 2007; 1: 146–54. 3. Stewart CJR, Hillery S, Platell C, Puppa G. Assessment of serosal invasion and criteria for the classification of pathological (p) T4 staging in colorectal carcinoma: confusions, controversies and criticisms. Cancers 2011; 3: 164–81. 4. Stewart CJR, Morris M, de Boer B, Iacopetta B. Identification of serosal invasion and extramural venous invasion on review of Dukes’ stage B colonic carcinomas and correlation with survival. Histopathology 2007; 51: 372–8. 5. Howlett CJ, Tweedle EJ, Driman DK. Use of an elastic stain to show venous invasion in colorectal carcinoma: a simple technique for detection of an important prognostic factor. J Clin Pathol 2009; 62: 1021–5. 6. Roxburgh CSD, McMillan DC, Anderson JH, McKee RF, Horgan PG, Foulis AK. Elastica staining for venous invasion results in superior prediction of cancer-specific survival in colorectal cancer. Ann Surg 2010; 252: 989–97. 7. Sejben I, Bori R, Cserni G. Venous invasion demonstrated by orcein staining of colorectal carcinoma specimens is associated with the development of distant metastases. J Clin Pathol 2010; 63: 575–8. 8. Kingston EF, Goulding H, Bateman AC. Vascular invasion is underrecognized in colorectal cancer using conventional hematoxylin and eosin staining. Dis Colon Rectum 2007; 50: 1867–72. 9. Bellis D, Marci V, Monga G. Light microscopic and immunohistochemical evaluation of vascular and neural invasion in colorectal cancer. Pathol Res Pract 1993; 189: 443–7. 10. Puppa G, Ueno H, Kayahara M, et al. Tumor deposits are encountered in advanced colorectal cancer and other adenocarcinomas: an expanded classification with implications for colorectal cancer staging system including a unifying concept of in-transit metastases. Mod Pathol 2009; 22: 410–5. 11. Nagtegaal ID, Quirke P. Colorectal tumour deposits in the mesorectum and pericolon: a critical review. Histopathology 2007; 51: 141–9.
DOI: 10.1097/PAT.0b013e32834e426d
Adult rhabdomyoma of the tongue in a child Sir, Rhabdomyoma (RM) is a benign mesenchymal tumour showing skeletal muscle differentiation, and it has been divided into cardiac and extracardiac types.1 Extracardiac RM may be classified histologically as fetal rhabdomyoma (F-RM) and adult rhabdomyoma (A-RM), which has a predilection for the head and neck regions.2 A-RM frequently occurs in adult males. There are only five A-RM cases previously reported in children in the English literature.3–7 Here we present the sixth A-RM found in the tongue of a child and summarise the clinicopathological characteristics of this rare entity. A 4-year-old girl came to our hospital because of a painless nodule on the right ventral side of her tongue that had grown gradually for 6 months. Her speaking and swallowing functions were slightly affected. She did not appear to suffer from any systemic disease and had no family history of hereditary disease. A distended oval mass could be observed on the right ventral surface of the tongue. The well-defined, moveable nodule was approximately 10 mm in diameter. The surface of the tumour was smooth and dark red in appearance. No enlarged lymph nodes were found in the submandibular or cervical areas. The conservative excision was performed from the surrounding musculature of the tongue. One year after the operation, the patient showed no evidence of recurrence. In macroscopy, the mass was covered with mucosa and surrounded by a little muscle tissue. The specimen was a
51
lobular, brown-red, moderate nodule measuring 10 10 8 mm with clear boundaries. Histologically, the densely packed, large, round and polygonal cells were comparted by delicate fibres and blood vessels, creating multilobular architecture (Fig. 1A). These well differentiated tumour cells had abundant eosinophilic granular cytoplasm with defined borders and small, round peripherally or centrally located nuclei with vesicular chromatin. Some cells with vacuolated cytoplasm exhibited spider web configurations (Fig. 1B). Serial sections of tumour stained with haematoxylin and eosin (H&E) showed no obvious cross striations or rod-like inclusions in the cytoplasm. Nuclear atypia and mitoses were absent in A-RM. By histochemistry, the glycogen-rich cytoplasm was periodic acid-Schiff (PAS) positive and diastase sensitive. Phosphotungstic acid haematoxylin (PTAH) (Fig. 1C) and Masson’s trichrome staining clearly showed cross striations and rod-like crystalloid structures in the cytoplasm. Immunohistochemically, the tumour cells showed nuclear positivity with MyoD1 (Fig. 1D) and cytoplasmic positivity with desmin and myoglobin. However, CKp, S100, synaptophysin, CD34, and CD68 were negative in this case. A-RM is a rare benign mesenchymal tumour with mature skeletal muscle differentiation. The tumour, with a predilection for the head and neck regions, might originate from the third or fourth branchial arch. So far, only six cases of A-RM, including our case, have occurred in children. They present at a mean age of 8 years and occur more frequently in males than females (2:1). The tongue is the predilection site of A-RM in children (50%). The tumour is commonly a painless, solitary, slow-growth nodule that can cause local compression symptoms, and the course of the disease ranges from 1 month to 1 year. The pathological diagnosis of A-RM should highlight vesicular cells, characteristic spider cells, and cross striations in the cytoplasm with regard to morphology. Cross striations and rod-like crystalloid structures in the cytoplasm are more distinctive with PTAH and Masson’s trichrome staining. Skeletal muscle differentiation is easily demonstrated on immunohistochemical stains with cytoplasmic positivity for desmin and myoglobin and nuclear positivity for MyoD1. MyoD1 expression in A-RM is not well described in the literature, while Koutsimpelas et al. stated MyoD1 positivity in an A-RM.8 Electron microscopy displays cytoplasmic myofilaments, Z-bands, and glycogen granules.9 Granular cell tumours (GCT), hibernoma, focal myositis and rhabdomyosarcoma should be ruled out before a diagnosis of A-RM is made. GCTs have a well-known predilection for the head and neck area and especially the tongue. They are composed of polygonal or spindle cells with eosinophilic granular cytoplasm. The nuclei are centrally or peripherally located and show dense chromatin. However, the cells of a GCT lack intracellular vacuolisation, cross striations, and rod-like crystalloid structures. Generally, intracytoplasmic granules can be stained by PAS reaction and are resistant to diastase. In particular, they show strong immunoreactivity for S100 protein and CD68, are consistently negative for myogenic markers, and can be distinguished from A-RM by ultrastructurally represented lysosomes. Hibernoma is another similar type of tumour, and is composed of polygonal or oval brown fat cells. These cells show a varying degree of vacuolisation and eosinophilic
Copyright © Royal College of Pathologists of Australasia. Unauthorized reproduction of this article is prohibited.
52
CORRESPONDENCE
Pathology (2012), 44(1), January
Fig. 1 (A) The densely packed, large, round and polygonal cells were comparted by delicate fibres and blood vessels, constituting multilobular architecture (H&E). (B) The well-differentiated tumour cells had abundant eosinophilic granular cytoplasm with defined borders. Some cells with vacuolated cytoplasm exhibited spider web configurations (H&E). (C) Some cross striations were clearly visible in the cytoplasm (PTAH) and the typical ‘jack-straw’ cytoplasmic crystalline inclusions were well demonstrated in the higher-power insert (PTAH, oil immersion). (D) Tumour cells showed nuclear positivity with MyoD1 (EnVision).
granular cytoplasm. The small nuclei are always localised centrally with vesicular chromatin. The tumour cells contain lipofusion pigment instead of cross striations or rod-like inclusions and are positive for oil red O and negative for PAS staining. Immunohistochemically, the cells are positive for S100 protein and negative for other musclespecific antibodies. Focal myositis is an uncommon inflammatory pseudotumour of skeletal muscle that can clinically present as a muscle mass in the extremities of young adults of both sexes. It is a solitary intramuscular lesion with specific histology including myopathic, focal neurogenic, fibrosis, and inflammatory features. Although the histological appearance differs somewhat from rhabdomyoma, it is worth keeping in mind. Rhabdomyosarcoma is the single largest category of soft tissue sarcoma in children, and it also has a tendency to occur in the head and neck. It is constituted by small round or spindle rhabdomyoblasts, occasionally showing bright eosinophilic cytoplasm and cross striations. These tumour cells present apparent nuclear atypia and mitoses. Our case of A-RM occurred in the tongue of a child, and there were no apparent cytoplasmic cross striations visible in H&E sections. In addition, myogenic markers such as MyoD1, desmin, and myoglobin were positive. Therefore, our case may have been mistaken for well-differentiated rhabdomyosarcoma. We should note that the tumour presented in this case had a clear demarcation from the surrounding muscle tissue accompanied by characteristic spider cells with no nuclear atypia or mitosis. The absence of atypical nuclei and abundant mitotic figures helps distinguish rhabdomyoma from rhabdomyosarcoma. In addition to the tumours mentioned above, we may exclude paraganglioma because of the negative results for neuron-specific enolase, chromogranin A, and synaptophysin.
The immunohistochemical expression of CK and epithelial membrane antigen in epithelial tumours such as oncocytoma can also be differentiated from those of A-RM. A-RM is a benign tumour lacking aggressive local growth or malignant potential. However, it can recur in the same anatomical site after incomplete excision.3 Andersen and Elling reported a case of A-RM in the oropharynx recurring three times within 35 years.10 Gibas and Miettinen presented a recurrent parapharyngeal A-RM in which the majority of cells showed a reciprocal translocation between chromosomes 15 and 17, and a minor clone was characterised by abnormalities of the long arm of chromosome 10, supporting the idea that A-RM is a true neoplasm.11 The recurrent tumours were histologically identical to the primary ones, without dedifferentiation to malignancy. Multilobular structures divided by fibrous connective tissues and incomplete resection of the tumour are currently considered the main causes of recurrence of A-RM. Positron emission tomography (PET) scanning can specify multifocal tumour extension. This is best confirmed by tomodensitometry and magnetic resonance imaging (MRI) before selecting the method of treatment.12 This implies that the appropriate treatment for A-RM is local excision of all lobules within a margin of normal tissue. A-RM is a rare type of benign mesenchymal tumour, which is extremely rare in children. The tongue is the most common site of A-RM in children. Accordingly, A-RM should be included in differential diagnosis of lingual tumours occurring in children. Noting the benign nature of A-RM, unnecessary or excessive treatment should be avoided.
Acknowledgements: Special thanks to Qinhe Fan, Director of the Pathology Department of Jiangsu Province Hospital, and Phil W. Allen, Professor of the Department of Pathology,
Copyright © Royal College of Pathologists of Australasia. Unauthorized reproduction of this article is prohibited.
CORRESPONDENCE
Flinders Medical Center, South Australia, for their kind advice and support. Conflicts of interest and sources of funding: Project supported by Medical Science and Technology Development Foundation, Nanjing Department of Health No.YKK07078; Research Project supported by Jiangsu Department of Health No.H200944. The authors have no conflicts of interests to declare. Xiaofeng Huang*{ Xudong Yang*{ Zhiyong Wang*{ Wei Li* Wenhui Jiang*{ Xianghua Chen*{ Qingang Hu*{ *Institute and Hospital of Stomatology, Nanjing University Medical School, and {Nanjing Stomatological Hospital, Nanjing, Jiangsu, PR China Contact Professor Q. Hu. E-mail: [email protected] 1. Smythe JF, Dyck JD, Smallhorn JF, et al. Natural history of cardiac rhabdomyoma in infancy and childhood. Am J Cardiol 1990; 66: 1247–9. 2. Di Sant’Agnese PA, Knowles DM. Extracardiac rhabdomyoma: a clinicopathologic study and review of the literature. Cancer 1980; 46: 780–9. 3. Knowles DM, Jakobiec FA. Rhabdomyoma of the orbit. Am J Ophthalmol 1975; 80: 1011–8. 4. Solomon MP, Tolete-Velcek F. Lingual rhabdomyoma (adult variant) in a child. J Pediatr Surg 1979; 14: 91–4. 5. Pai GK, Pai PK, Kamath SM. Adult rhabdomyoma of the esophagus. J Pediatr Surg 1987; 22: 991–2. 6. Cacciari A, Predieri B, Mordenti M, et al. Rhabdomyoma of a rare type in a child: case report and literature review. Eur J Pediatr Surg 2001; 11: 66–8. 7. Firdevs V, Sina U, Burcu S. Adult type rhabdomyoma in a child:. Oral Oncology EXTRA 2006; 42: 213–6. 8. Koutsimpelas D, Weber A, Lippert BM, et al. Multifocal adult rhabdomyoma of the head and neck: a case report and literature review. Auris Nasus Larynx 2008; 35: 313–7. 9. Cleveland DB, Chen SY, Allen CM, et al. Adult rhabdomyoma. A light microscopic, ultrastructural, virologic, and immunologic analysis. Oral Surg Oral Med Oral Pathol 1994; 77: 147–53. 10. Andersen CB, Elling F. Adult rhabdomyoma of the oropharynx recurring three times within thirty-five years. Acta Pathol Microbiol Immunol Scand A 1986; 94: 281–4. 11. Gibas Z, Miettinen M. Recurrent parapharyngeal rhabdomyoma. Evidence of neoplstic nature of the tumor from cytogenetic study. Am J Surg Pathol 1992; 16: 721–8. 12. Bizon A, Capitain O, Girault S, et al. Multifocal adult rhabdomyoma and positron emission tomography. Ann Otolaryngol Chir Cervicofac 2008; 125: 213–7.
53
reaction positive; conversely, the paraganglia associated with the great vessels, typically associated with the parasympathetic nervous system, are chromaffin reaction negative, and infrequently release catecholamines.1 Paragangliomas are rare tumours arising from these collections of neuroendocrine cells affecting 1 in 2 000 000 people, with the most common locations being the adrenal medulla (phaeochromocytoma) and the head and neck region. Paraganglia are also found in a variety of other sites, including solid organs and hollow viscus, explaining the occurrence of paragangliomas in these sites.2 Primary paragangliomas of the pancreas without metastasis are considered benign entities. They are extremely rare, with only a handful of cases having been previously reported. To our knowledge there have been no reported cases of malignant primary paraganglioma of the pancreas; here we report such a case. The patient was a 65-year-old Caucasian woman, who presented with bilateral ovarian cysts and an incidentally discovered pancreatic mass. She had presented to an outside institution with dyspareunia, where bilateral ovarian cysts were discovered. She was scheduled for pelvic ultrasound, at which time a pancreatic mass was incidentally discovered. An abdominal CT scan was performed which showed a 2.1 cm mass with mixed attenuation and areas of enhancement in the uncinate process of the pancreas; in addition, a 8.7 cm cyst and 7.5 cm cyst were shown in the left and right ovaries, respectively. There was no history of hypertension and plasma metanepherines were not performed. The patient underwent a pancreaticoduodenectomy and bilateral salpingo-oophorectomy. The specimen consisted of a pancreatico-duodenectomy with a 2.0 cm well-circumscribed, solid, tan-white tumour in the head of the pancreas; there were no associated areas of haemorrhage or necrosis. Gross and microscopic examination showed the tumour to be entirely intrapancreatic (i.e., completely surrounded by pancreatic tissue). The margins of the specimen were not grossly involved with tumour. Intraoperative frozen section performed on the bilateral ovarian cysts showed the left ovarian cyst to be a serous cystadenofibroma and the right ovarian cyst to be a serous cystadenoma, which was confirmed on permanent sections. Microscopic sections of the pancreatic tumour (Fig. 1) showed a well circumscribed but unencapsulated mass composed of nests of cells separated by fibrovascular septa, forming a ‘zellballen’ architecture. Cytologically the tumour cells were medium-to-large sized with
DOI: 10.1097/PAT.0b013e32834e42a0
Malignant paraganglioma of the pancreas Sir, Paraganglia are neuroendocrine cells associated with the autonomic nervous system, either sympathetic or parasympathetic. The paravertebral paraganglia are typically associated with the sympathetic nervous system, and as such, are chromaffin
Fig. 1 Nested pattern of the intra-pancreatic paraganglioma. Higher magnification (inset) shows focal spindling of the tumour cells and stippled chromatin pattern (H&E).
Copyright © Royal College of Pathologists of Australasia. Unauthorized reproduction of this article is prohibited.
2. Marshall JL, Haller DG, de Gramont A, et al. Adjuvant therapy for stage II and III colon cancer: consensus report of the International Society of Gastrointestinal Oncology. Gastrointest Cancer Res 2007; 1: 146–54. 3. Stewart CJR, Hillery S, Platell C, Puppa G. Assessment of serosal invasion and criteria for the classification of pathological (p) T4 staging in colorectal carcinoma: confusions, controversies and criticisms. Cancers 2011; 3: 164–81. 4. Stewart CJR, Morris M, de Boer B, Iacopetta B. Identification of serosal invasion and extramural venous invasion on review of Dukes’ stage B colonic carcinomas and correlation with survival. Histopathology 2007; 51: 372–8. 5. Howlett CJ, Tweedle EJ, Driman DK. Use of an elastic stain to show venous invasion in colorectal carcinoma: a simple technique for detection of an important prognostic factor. J Clin Pathol 2009; 62: 1021–5. 6. Roxburgh CSD, McMillan DC, Anderson JH, McKee RF, Horgan PG, Foulis AK. Elastica staining for venous invasion results in superior prediction of cancer-specific survival in colorectal cancer. Ann Surg 2010; 252: 989–97. 7. Sejben I, Bori R, Cserni G. Venous invasion demonstrated by orcein staining of colorectal carcinoma specimens is associated with the development of distant metastases. J Clin Pathol 2010; 63: 575–8. 8. Kingston EF, Goulding H, Bateman AC. Vascular invasion is underrecognized in colorectal cancer using conventional hematoxylin and eosin staining. Dis Colon Rectum 2007; 50: 1867–72. 9. Bellis D, Marci V, Monga G. Light microscopic and immunohistochemical evaluation of vascular and neural invasion in colorectal cancer. Pathol Res Pract 1993; 189: 443–7. 10. Puppa G, Ueno H, Kayahara M, et al. Tumor deposits are encountered in advanced colorectal cancer and other adenocarcinomas: an expanded classification with implications for colorectal cancer staging system including a unifying concept of in-transit metastases. Mod Pathol 2009; 22: 410–5. 11. Nagtegaal ID, Quirke P. Colorectal tumour deposits in the mesorectum and pericolon: a critical review. Histopathology 2007; 51: 141–9.
DOI: 10.1097/PAT.0b013e32834e426d
Adult rhabdomyoma of the tongue in a child Sir, Rhabdomyoma (RM) is a benign mesenchymal tumour showing skeletal muscle differentiation, and it has been divided into cardiac and extracardiac types.1 Extracardiac RM may be classified histologically as fetal rhabdomyoma (F-RM) and adult rhabdomyoma (A-RM), which has a predilection for the head and neck regions.2 A-RM frequently occurs in adult males. There are only five A-RM cases previously reported in children in the English literature.3–7 Here we present the sixth A-RM found in the tongue of a child and summarise the clinicopathological characteristics of this rare entity. A 4-year-old girl came to our hospital because of a painless nodule on the right ventral side of her tongue that had grown gradually for 6 months. Her speaking and swallowing functions were slightly affected. She did not appear to suffer from any systemic disease and had no family history of hereditary disease. A distended oval mass could be observed on the right ventral surface of the tongue. The well-defined, moveable nodule was approximately 10 mm in diameter. The surface of the tumour was smooth and dark red in appearance. No enlarged lymph nodes were found in the submandibular or cervical areas. The conservative excision was performed from the surrounding musculature of the tongue. One year after the operation, the patient showed no evidence of recurrence. In macroscopy, the mass was covered with mucosa and surrounded by a little muscle tissue. The specimen was a
51
lobular, brown-red, moderate nodule measuring 10 10 8 mm with clear boundaries. Histologically, the densely packed, large, round and polygonal cells were comparted by delicate fibres and blood vessels, creating multilobular architecture (Fig. 1A). These well differentiated tumour cells had abundant eosinophilic granular cytoplasm with defined borders and small, round peripherally or centrally located nuclei with vesicular chromatin. Some cells with vacuolated cytoplasm exhibited spider web configurations (Fig. 1B). Serial sections of tumour stained with haematoxylin and eosin (H&E) showed no obvious cross striations or rod-like inclusions in the cytoplasm. Nuclear atypia and mitoses were absent in A-RM. By histochemistry, the glycogen-rich cytoplasm was periodic acid-Schiff (PAS) positive and diastase sensitive. Phosphotungstic acid haematoxylin (PTAH) (Fig. 1C) and Masson’s trichrome staining clearly showed cross striations and rod-like crystalloid structures in the cytoplasm. Immunohistochemically, the tumour cells showed nuclear positivity with MyoD1 (Fig. 1D) and cytoplasmic positivity with desmin and myoglobin. However, CKp, S100, synaptophysin, CD34, and CD68 were negative in this case. A-RM is a rare benign mesenchymal tumour with mature skeletal muscle differentiation. The tumour, with a predilection for the head and neck regions, might originate from the third or fourth branchial arch. So far, only six cases of A-RM, including our case, have occurred in children. They present at a mean age of 8 years and occur more frequently in males than females (2:1). The tongue is the predilection site of A-RM in children (50%). The tumour is commonly a painless, solitary, slow-growth nodule that can cause local compression symptoms, and the course of the disease ranges from 1 month to 1 year. The pathological diagnosis of A-RM should highlight vesicular cells, characteristic spider cells, and cross striations in the cytoplasm with regard to morphology. Cross striations and rod-like crystalloid structures in the cytoplasm are more distinctive with PTAH and Masson’s trichrome staining. Skeletal muscle differentiation is easily demonstrated on immunohistochemical stains with cytoplasmic positivity for desmin and myoglobin and nuclear positivity for MyoD1. MyoD1 expression in A-RM is not well described in the literature, while Koutsimpelas et al. stated MyoD1 positivity in an A-RM.8 Electron microscopy displays cytoplasmic myofilaments, Z-bands, and glycogen granules.9 Granular cell tumours (GCT), hibernoma, focal myositis and rhabdomyosarcoma should be ruled out before a diagnosis of A-RM is made. GCTs have a well-known predilection for the head and neck area and especially the tongue. They are composed of polygonal or spindle cells with eosinophilic granular cytoplasm. The nuclei are centrally or peripherally located and show dense chromatin. However, the cells of a GCT lack intracellular vacuolisation, cross striations, and rod-like crystalloid structures. Generally, intracytoplasmic granules can be stained by PAS reaction and are resistant to diastase. In particular, they show strong immunoreactivity for S100 protein and CD68, are consistently negative for myogenic markers, and can be distinguished from A-RM by ultrastructurally represented lysosomes. Hibernoma is another similar type of tumour, and is composed of polygonal or oval brown fat cells. These cells show a varying degree of vacuolisation and eosinophilic
Copyright © Royal College of Pathologists of Australasia. Unauthorized reproduction of this article is prohibited.
52
CORRESPONDENCE
Pathology (2012), 44(1), January
Fig. 1 (A) The densely packed, large, round and polygonal cells were comparted by delicate fibres and blood vessels, constituting multilobular architecture (H&E). (B) The well-differentiated tumour cells had abundant eosinophilic granular cytoplasm with defined borders. Some cells with vacuolated cytoplasm exhibited spider web configurations (H&E). (C) Some cross striations were clearly visible in the cytoplasm (PTAH) and the typical ‘jack-straw’ cytoplasmic crystalline inclusions were well demonstrated in the higher-power insert (PTAH, oil immersion). (D) Tumour cells showed nuclear positivity with MyoD1 (EnVision).
granular cytoplasm. The small nuclei are always localised centrally with vesicular chromatin. The tumour cells contain lipofusion pigment instead of cross striations or rod-like inclusions and are positive for oil red O and negative for PAS staining. Immunohistochemically, the cells are positive for S100 protein and negative for other musclespecific antibodies. Focal myositis is an uncommon inflammatory pseudotumour of skeletal muscle that can clinically present as a muscle mass in the extremities of young adults of both sexes. It is a solitary intramuscular lesion with specific histology including myopathic, focal neurogenic, fibrosis, and inflammatory features. Although the histological appearance differs somewhat from rhabdomyoma, it is worth keeping in mind. Rhabdomyosarcoma is the single largest category of soft tissue sarcoma in children, and it also has a tendency to occur in the head and neck. It is constituted by small round or spindle rhabdomyoblasts, occasionally showing bright eosinophilic cytoplasm and cross striations. These tumour cells present apparent nuclear atypia and mitoses. Our case of A-RM occurred in the tongue of a child, and there were no apparent cytoplasmic cross striations visible in H&E sections. In addition, myogenic markers such as MyoD1, desmin, and myoglobin were positive. Therefore, our case may have been mistaken for well-differentiated rhabdomyosarcoma. We should note that the tumour presented in this case had a clear demarcation from the surrounding muscle tissue accompanied by characteristic spider cells with no nuclear atypia or mitosis. The absence of atypical nuclei and abundant mitotic figures helps distinguish rhabdomyoma from rhabdomyosarcoma. In addition to the tumours mentioned above, we may exclude paraganglioma because of the negative results for neuron-specific enolase, chromogranin A, and synaptophysin.
The immunohistochemical expression of CK and epithelial membrane antigen in epithelial tumours such as oncocytoma can also be differentiated from those of A-RM. A-RM is a benign tumour lacking aggressive local growth or malignant potential. However, it can recur in the same anatomical site after incomplete excision.3 Andersen and Elling reported a case of A-RM in the oropharynx recurring three times within 35 years.10 Gibas and Miettinen presented a recurrent parapharyngeal A-RM in which the majority of cells showed a reciprocal translocation between chromosomes 15 and 17, and a minor clone was characterised by abnormalities of the long arm of chromosome 10, supporting the idea that A-RM is a true neoplasm.11 The recurrent tumours were histologically identical to the primary ones, without dedifferentiation to malignancy. Multilobular structures divided by fibrous connective tissues and incomplete resection of the tumour are currently considered the main causes of recurrence of A-RM. Positron emission tomography (PET) scanning can specify multifocal tumour extension. This is best confirmed by tomodensitometry and magnetic resonance imaging (MRI) before selecting the method of treatment.12 This implies that the appropriate treatment for A-RM is local excision of all lobules within a margin of normal tissue. A-RM is a rare type of benign mesenchymal tumour, which is extremely rare in children. The tongue is the most common site of A-RM in children. Accordingly, A-RM should be included in differential diagnosis of lingual tumours occurring in children. Noting the benign nature of A-RM, unnecessary or excessive treatment should be avoided.
Acknowledgements: Special thanks to Qinhe Fan, Director of the Pathology Department of Jiangsu Province Hospital, and Phil W. Allen, Professor of the Department of Pathology,
Copyright © Royal College of Pathologists of Australasia. Unauthorized reproduction of this article is prohibited.
CORRESPONDENCE
Flinders Medical Center, South Australia, for their kind advice and support. Conflicts of interest and sources of funding: Project supported by Medical Science and Technology Development Foundation, Nanjing Department of Health No.YKK07078; Research Project supported by Jiangsu Department of Health No.H200944. The authors have no conflicts of interests to declare. Xiaofeng Huang*{ Xudong Yang*{ Zhiyong Wang*{ Wei Li* Wenhui Jiang*{ Xianghua Chen*{ Qingang Hu*{ *Institute and Hospital of Stomatology, Nanjing University Medical School, and {Nanjing Stomatological Hospital, Nanjing, Jiangsu, PR China Contact Professor Q. Hu. E-mail: [email protected] 1. Smythe JF, Dyck JD, Smallhorn JF, et al. Natural history of cardiac rhabdomyoma in infancy and childhood. Am J Cardiol 1990; 66: 1247–9. 2. Di Sant’Agnese PA, Knowles DM. Extracardiac rhabdomyoma: a clinicopathologic study and review of the literature. Cancer 1980; 46: 780–9. 3. Knowles DM, Jakobiec FA. Rhabdomyoma of the orbit. Am J Ophthalmol 1975; 80: 1011–8. 4. Solomon MP, Tolete-Velcek F. Lingual rhabdomyoma (adult variant) in a child. J Pediatr Surg 1979; 14: 91–4. 5. Pai GK, Pai PK, Kamath SM. Adult rhabdomyoma of the esophagus. J Pediatr Surg 1987; 22: 991–2. 6. Cacciari A, Predieri B, Mordenti M, et al. Rhabdomyoma of a rare type in a child: case report and literature review. Eur J Pediatr Surg 2001; 11: 66–8. 7. Firdevs V, Sina U, Burcu S. Adult type rhabdomyoma in a child:. Oral Oncology EXTRA 2006; 42: 213–6. 8. Koutsimpelas D, Weber A, Lippert BM, et al. Multifocal adult rhabdomyoma of the head and neck: a case report and literature review. Auris Nasus Larynx 2008; 35: 313–7. 9. Cleveland DB, Chen SY, Allen CM, et al. Adult rhabdomyoma. A light microscopic, ultrastructural, virologic, and immunologic analysis. Oral Surg Oral Med Oral Pathol 1994; 77: 147–53. 10. Andersen CB, Elling F. Adult rhabdomyoma of the oropharynx recurring three times within thirty-five years. Acta Pathol Microbiol Immunol Scand A 1986; 94: 281–4. 11. Gibas Z, Miettinen M. Recurrent parapharyngeal rhabdomyoma. Evidence of neoplstic nature of the tumor from cytogenetic study. Am J Surg Pathol 1992; 16: 721–8. 12. Bizon A, Capitain O, Girault S, et al. Multifocal adult rhabdomyoma and positron emission tomography. Ann Otolaryngol Chir Cervicofac 2008; 125: 213–7.
53
reaction positive; conversely, the paraganglia associated with the great vessels, typically associated with the parasympathetic nervous system, are chromaffin reaction negative, and infrequently release catecholamines.1 Paragangliomas are rare tumours arising from these collections of neuroendocrine cells affecting 1 in 2 000 000 people, with the most common locations being the adrenal medulla (phaeochromocytoma) and the head and neck region. Paraganglia are also found in a variety of other sites, including solid organs and hollow viscus, explaining the occurrence of paragangliomas in these sites.2 Primary paragangliomas of the pancreas without metastasis are considered benign entities. They are extremely rare, with only a handful of cases having been previously reported. To our knowledge there have been no reported cases of malignant primary paraganglioma of the pancreas; here we report such a case. The patient was a 65-year-old Caucasian woman, who presented with bilateral ovarian cysts and an incidentally discovered pancreatic mass. She had presented to an outside institution with dyspareunia, where bilateral ovarian cysts were discovered. She was scheduled for pelvic ultrasound, at which time a pancreatic mass was incidentally discovered. An abdominal CT scan was performed which showed a 2.1 cm mass with mixed attenuation and areas of enhancement in the uncinate process of the pancreas; in addition, a 8.7 cm cyst and 7.5 cm cyst were shown in the left and right ovaries, respectively. There was no history of hypertension and plasma metanepherines were not performed. The patient underwent a pancreaticoduodenectomy and bilateral salpingo-oophorectomy. The specimen consisted of a pancreatico-duodenectomy with a 2.0 cm well-circumscribed, solid, tan-white tumour in the head of the pancreas; there were no associated areas of haemorrhage or necrosis. Gross and microscopic examination showed the tumour to be entirely intrapancreatic (i.e., completely surrounded by pancreatic tissue). The margins of the specimen were not grossly involved with tumour. Intraoperative frozen section performed on the bilateral ovarian cysts showed the left ovarian cyst to be a serous cystadenofibroma and the right ovarian cyst to be a serous cystadenoma, which was confirmed on permanent sections. Microscopic sections of the pancreatic tumour (Fig. 1) showed a well circumscribed but unencapsulated mass composed of nests of cells separated by fibrovascular septa, forming a ‘zellballen’ architecture. Cytologically the tumour cells were medium-to-large sized with
DOI: 10.1097/PAT.0b013e32834e42a0
Malignant paraganglioma of the pancreas Sir, Paraganglia are neuroendocrine cells associated with the autonomic nervous system, either sympathetic or parasympathetic. The paravertebral paraganglia are typically associated with the sympathetic nervous system, and as such, are chromaffin
Fig. 1 Nested pattern of the intra-pancreatic paraganglioma. Higher magnification (inset) shows focal spindling of the tumour cells and stippled chromatin pattern (H&E).
Copyright © Royal College of Pathologists of Australasia. Unauthorized reproduction of this article is prohibited.