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Intraductal Papillary Carcinoma of the Parotid Gland with Low Malignancy
PATHOLOGY RESEARCH AND PRACTICE © Urban & Fischer Verlag
http://www.urbanfischer.de/journalslprp
Intraductal Papillary Carcinoma of the Parotid Gland with Low Malignancy Laura Caramanico, Paolo Marcone, Patrizia Rovere and Carlo Della Rocca Department of Experimental Medicine and Pathology, "La Sapienza" University, Rome, Italy
Summary
Table 1. WHO classification of salivary gland tumors (1996)
A peculiar case of papillary carcinoma arising in the parotid gland is reported. A 68-year-old woman presented with a right, painless, parotid mass, measuring approximately 3 em in greatest diameter. A conservative parotidectomy was performed. Histologically, the neoplasm showed exophytic papillary projections into a cavity. The cells were focally suggestive of epidermoidal differentiation, whereas a transitional differentiation was noted in other portions, as in bladder papilloma. Immunohistochemical studies showed strong positivity of the neoplastic cells for cytokeratin and weak positivity for peNA and Mib-L We classified this neoplasm among the papillary tumors with a low-grade of malignancy.
Benign Epithelial Neoplasms Mixed tumor (pleomorphic adenoma). Myoepithelioma, Warthin's tumor, Basal cell adenoma, Canalicular adenoma, Oncocytoma, Cystadenoma, Ductal papillomas Sialadenoma papilliferum Inverted ductal papilloma Intraductal papilloma Lymphadenomas and sebaceous adenomas, Sialoblastoma
Key words: Papillary carcinoma - Parotid - Bladder Transitional papilloma
Introduction Benign tumors of the salivary glands with prominent papillary growth pattern are rare epithelial neoplasms. At present, three types are recognized: sialadenoma papilliferum, inverted ductal papilloma, and intraductal papilloma (Tab. 1)[2, 5]. The papillary neoplasms are generally localized in the minor salivary glands. Address for correspondence: C. Della Rocca, MD, Department of Experimental Medicine and Pathology, Pathological Anatomy V, "La Sapienza" University, Viale Regina Elena 324, I - 00161 Rome, Italy. Phone: ++39-6-499-70731, Fax: ++39-6-495-7685, e-mail: [email protected] Pathol. Res. Pract. 195: 253-256 (1999)
Malignant Epithelial Neoplasms Mucoepidermoid carcinoma, Adenocarcinoma, Acinic cell adenocarcinoma, Adenoid cystic carcinoma, Polymorphous low-grade adenocarcinoma, Malignant mixed tumors Carcinoma ex mixed tumor Carcinosarcoma Metastasizing mixed tumor Squamous cell carcinoma, Basal cell adenocarcinoma, Epithelial-myoepithelial carcinoma, Clear cell adenocarcinoma, Cystadenocarcinoma, Undifferentiated carcinomas Small cell undifferentiated carcinoma Large cell undifferentiated carcinoma Lymphoepithelial carcinoma Oncocytic carcinoma, Salivary duct carcinoma, Sebaceous adenocarcinoma and lymphadenocarcinoma, Myoepithelial carcinoma, Adenosquamous carcinoma, Mucinous adenocarcinoma Mesenchimal Neoplasms Benign Sarcomas Malignant Lymphomas Metastatic Tumors Non-neoplastic Tumor-like Conditions 0344-0338/99/195/4-253 $12.00/0
254 . L. Caramanico et al.
We report a rare case of papillary tumor arising in the parotid gland and discuss its distinctive morphologic appearance.
Clinical History
Material and Methods The surgical specimen was fixed in 4% formaldehyde and routinely embedded in paraffin . Consecutive sections (5 urn thick) were obtained and stained with hematoxylin and eosin and treated for immunohi stochemistry. Immunohistochemical staining was performed by using an indirect immunoperoxidase technique . The following antibodies were used: cytokeratin (monoclonal ; dilution 1:20, DAKO), vimentin (monoclonal ; dilution 1:20, DAKO) , S100 protein (polyclonal; dilution 1:300, DAKO) , smooth muscle actin (monoclonal; dilution 1:20, DAKO), PCNA (monoclonal; dilution 1:50, DAKO), and MIB-1 (monoclonal; dilution 1:50, DBA) .
A 68-year-old woman was admitted to the Division of Oral Surgery with a right parotid mass that had developed during the last ten months. The mass was painless but had slowly increased in size. Facial nerve function was intact, and examination of the ear, nose and throat system was otherwise normal. Ultrasound examination revealed a well-circumscribed hypoechogenic solid nodule of the right parotid gland measuring approximately 3 cm in greatest diameter, without lyrnphonodal involvement. The patient therefore underwent a conservative parotidectomy with a simple excision of the neoplasm. Histologic examination showed a "transitional cell papilloma" with a low grade of malignancy. According to these histologic data, the clinicians investigated the patient's urinary tract for excluding a distant metastasis of urothelial neoplasia. After surgery, the patient was in good health without radiotherapy and chemotherapy. Seven years later she died of an acute myocardial infarction (autopsy was not authorized).
Gross specimen examination revealed a well-circumscribed lesion of firm consistency; the cut surface was white-grayish without clear necrotic and hemorragic areas. Microscopically, the tumor showed many papillary projections into a cavity that probably represented a dilatation of a salivary gland excretory duct (Fig. I). These papillary structures were supported by fibrovascular cores and lined by stratified neoplastic cells (Fig. 2). In some areas, the cells showed an epidermoidal differentiation, whereas in other portions a tran-
Fig. 1. The neoplasm is made up of papillary projections growing into an ectasic cavity (HE, original magnification 4x).
Fig. 2. The papillae are covered by stratified neoplastic cells (HE, original magnification 25x) .
Pathological Findings
Papillary Carcinoma of the Parotid Gland . 255
Fig. 3. An area of epidermoid metaplasia is evident (arrow), but the major part of the neoplasia has a clear transitional appearance (HE, original magnification 25x).
Fig. 4. Areas of infiltration are present in the surrounding fibrous connective tissue (HE, original magnification 4x).
sitional differentiation was found, as in bladder papilloma (Fig. 3). The cellular elements appeared to be moderately pleomorphic with well-defined limits. The cytoplasm of these cells was abundant and eosinophilic with oval or round nuclei, finely scattered chromatin, prominent nucleoli , and evidence of mitotic activity. The lesion was well demarcated and surrounded by fibrous connective tissue with area s of infiltration (Fig. 4). Areas of necrosis and hemorragic infarction were also noted. An accurate immunohistochemical study showed that the cellular elements were strongly positive for cytokeratin, which is consistent with features of typical epithelial cells, but negative for vimentin, S-100 protein, and smooth muscle actin. Furthermore, the weak positivity towards PCNA and MIB-I (1-5% of the nuclei were positive) suggested a low grade malignancy of the tumor.
found in Warthin's tumor, cystadenoma and its malignant variant, acinic cell adenocarcinoma, mucoepidermoid carcinoma, and polymorphous low-grade adenocarcinoma. Nevertheless, ductal papillomas constitute a separate category for their distinctive clinical and morphological features ; they are quite rare and typically occur in the minor salivary glands . To date, only three cases of papilloma of the parotid gland have been reported. The first case was described by Abrams and Finck [1J, who reported a rare large neoplasm (7.5 em greatest diameter) involving the parotid gland and extending through the overlying skin. It consisted of numerous papillary projections covered by an edematous squamous epithelium with no signs of dysplasia, while the deeper papillary surfaces were covered by an eosinophilic columnar epithelium alternating with differentiated mucous cells. The authors called this neoplasm "sial adenoma papilliferum" due to its similarity with the syringadenoma of the scalp. The second case was reported by Gardiner and colleagues [3J, who defined the term "inverted ductal papilloma" of the parotid gland. The neoplasm showed a marked proliferation of mostly uniform squamous cells, with no cellular atypia or keratinization. Such cellular proliferation determined the formation of pseudo lobular structures
Discussion A morphologic papillary-type pattern is a common feature of numerous salivary gland tumors. It can be
256 . L. Caramanico et al.
invaginating into the adjacent connective tissue stroma around wide cystic spaces. No mitotic figures were observed. The third and most recent case was described by King and Hill [4J , who reported a well-circumscribed parotid tumor in an 87-year-old man. Microscopically, the tumor had a papillary architecture lined by a double layer of cells: the inner layer was made up of cells with abundant clear cytoplasm and vesicular nuclei with prominent nucleoli , while the outer layer consisted of smaller cells with scanty acidophilic cytoplasm and dark nuclei. Also, in this case there was no evidence of mitotic activity, nuclear atypia or capsular invasion. The authors interpreted this tumor as "intraductal papilloma." The case presented here has some particularities: the papillary configuration was evident, which led us to consider a simple papilloma of the parotid gland, a rare tumor. However, characteristically, the epithelial cells lining the papillae showed in some areas a squamoustype differentiation, while in others we noticed a transitional structure that was very similar to the bladder epithelium, without any columnar epithelium covering the papillary projections, which, in contrast, is described in the inverted ductal papillomas. These features, which are unusual for salivary glands, and the clinical biological behavior of this neoplasm closely resembled neoplastic lesions of the bladder, according to our grading system. Nevertheless , as in other non-transitional epithelial cells, it can be hypothesized that an incomplete mal-
pighian metaplasia occurred in this histologic presentation. Furthermore, even if our case appears to be a salivary gland papilloma, it shares some unique characteristics with the cellular pleomorphism, the invasive growth pattern, and the pattern of the immunohi stochemical proliferation markers that led us to classify this neoplasm among the low-grade malignancy salivary gland lesions. In conclusion, this appears to be the first case of salivary gland, bladder-like low-grade papillary carcinoma.
References 1. Abrams AM, Finck FM (1969) Sialadenoma papilliferum. A previously unreported salivary gland tumor. Cancer 24: 1057-1063 2. Ellis GL, Auclair PL (1996) Ductal papilloma. (Tumours of the salivary glands.)AFIP: 120-130. 3. Gardiner GW, Briant TD, Sheman L (1984) Inverted ductal papilloma of the parotid gland. J Otolaryngolog y 13: 23- 26 4. King PH, Hill J (1993) Intraductal papilloma of parotid gland. J Clin Pathol46: 175-176 5. Ellis GL, Auclair PL (1996) Classification. (Tumor of the salivary glands.) AFIP: 27-29
Received: September 10, 1998 Accepted in revised version: February 12, 1999
http://www.urbanfischer.de/journalslprp
Intraductal Papillary Carcinoma of the Parotid Gland with Low Malignancy Laura Caramanico, Paolo Marcone, Patrizia Rovere and Carlo Della Rocca Department of Experimental Medicine and Pathology, "La Sapienza" University, Rome, Italy
Summary
Table 1. WHO classification of salivary gland tumors (1996)
A peculiar case of papillary carcinoma arising in the parotid gland is reported. A 68-year-old woman presented with a right, painless, parotid mass, measuring approximately 3 em in greatest diameter. A conservative parotidectomy was performed. Histologically, the neoplasm showed exophytic papillary projections into a cavity. The cells were focally suggestive of epidermoidal differentiation, whereas a transitional differentiation was noted in other portions, as in bladder papilloma. Immunohistochemical studies showed strong positivity of the neoplastic cells for cytokeratin and weak positivity for peNA and Mib-L We classified this neoplasm among the papillary tumors with a low-grade of malignancy.
Benign Epithelial Neoplasms Mixed tumor (pleomorphic adenoma). Myoepithelioma, Warthin's tumor, Basal cell adenoma, Canalicular adenoma, Oncocytoma, Cystadenoma, Ductal papillomas Sialadenoma papilliferum Inverted ductal papilloma Intraductal papilloma Lymphadenomas and sebaceous adenomas, Sialoblastoma
Key words: Papillary carcinoma - Parotid - Bladder Transitional papilloma
Introduction Benign tumors of the salivary glands with prominent papillary growth pattern are rare epithelial neoplasms. At present, three types are recognized: sialadenoma papilliferum, inverted ductal papilloma, and intraductal papilloma (Tab. 1)[2, 5]. The papillary neoplasms are generally localized in the minor salivary glands. Address for correspondence: C. Della Rocca, MD, Department of Experimental Medicine and Pathology, Pathological Anatomy V, "La Sapienza" University, Viale Regina Elena 324, I - 00161 Rome, Italy. Phone: ++39-6-499-70731, Fax: ++39-6-495-7685, e-mail: [email protected] Pathol. Res. Pract. 195: 253-256 (1999)
Malignant Epithelial Neoplasms Mucoepidermoid carcinoma, Adenocarcinoma, Acinic cell adenocarcinoma, Adenoid cystic carcinoma, Polymorphous low-grade adenocarcinoma, Malignant mixed tumors Carcinoma ex mixed tumor Carcinosarcoma Metastasizing mixed tumor Squamous cell carcinoma, Basal cell adenocarcinoma, Epithelial-myoepithelial carcinoma, Clear cell adenocarcinoma, Cystadenocarcinoma, Undifferentiated carcinomas Small cell undifferentiated carcinoma Large cell undifferentiated carcinoma Lymphoepithelial carcinoma Oncocytic carcinoma, Salivary duct carcinoma, Sebaceous adenocarcinoma and lymphadenocarcinoma, Myoepithelial carcinoma, Adenosquamous carcinoma, Mucinous adenocarcinoma Mesenchimal Neoplasms Benign Sarcomas Malignant Lymphomas Metastatic Tumors Non-neoplastic Tumor-like Conditions 0344-0338/99/195/4-253 $12.00/0
254 . L. Caramanico et al.
We report a rare case of papillary tumor arising in the parotid gland and discuss its distinctive morphologic appearance.
Clinical History
Material and Methods The surgical specimen was fixed in 4% formaldehyde and routinely embedded in paraffin . Consecutive sections (5 urn thick) were obtained and stained with hematoxylin and eosin and treated for immunohi stochemistry. Immunohistochemical staining was performed by using an indirect immunoperoxidase technique . The following antibodies were used: cytokeratin (monoclonal ; dilution 1:20, DAKO), vimentin (monoclonal ; dilution 1:20, DAKO) , S100 protein (polyclonal; dilution 1:300, DAKO) , smooth muscle actin (monoclonal; dilution 1:20, DAKO), PCNA (monoclonal; dilution 1:50, DAKO), and MIB-1 (monoclonal; dilution 1:50, DBA) .
A 68-year-old woman was admitted to the Division of Oral Surgery with a right parotid mass that had developed during the last ten months. The mass was painless but had slowly increased in size. Facial nerve function was intact, and examination of the ear, nose and throat system was otherwise normal. Ultrasound examination revealed a well-circumscribed hypoechogenic solid nodule of the right parotid gland measuring approximately 3 cm in greatest diameter, without lyrnphonodal involvement. The patient therefore underwent a conservative parotidectomy with a simple excision of the neoplasm. Histologic examination showed a "transitional cell papilloma" with a low grade of malignancy. According to these histologic data, the clinicians investigated the patient's urinary tract for excluding a distant metastasis of urothelial neoplasia. After surgery, the patient was in good health without radiotherapy and chemotherapy. Seven years later she died of an acute myocardial infarction (autopsy was not authorized).
Gross specimen examination revealed a well-circumscribed lesion of firm consistency; the cut surface was white-grayish without clear necrotic and hemorragic areas. Microscopically, the tumor showed many papillary projections into a cavity that probably represented a dilatation of a salivary gland excretory duct (Fig. I). These papillary structures were supported by fibrovascular cores and lined by stratified neoplastic cells (Fig. 2). In some areas, the cells showed an epidermoidal differentiation, whereas in other portions a tran-
Fig. 1. The neoplasm is made up of papillary projections growing into an ectasic cavity (HE, original magnification 4x).
Fig. 2. The papillae are covered by stratified neoplastic cells (HE, original magnification 25x) .
Pathological Findings
Papillary Carcinoma of the Parotid Gland . 255
Fig. 3. An area of epidermoid metaplasia is evident (arrow), but the major part of the neoplasia has a clear transitional appearance (HE, original magnification 25x).
Fig. 4. Areas of infiltration are present in the surrounding fibrous connective tissue (HE, original magnification 4x).
sitional differentiation was found, as in bladder papilloma (Fig. 3). The cellular elements appeared to be moderately pleomorphic with well-defined limits. The cytoplasm of these cells was abundant and eosinophilic with oval or round nuclei, finely scattered chromatin, prominent nucleoli , and evidence of mitotic activity. The lesion was well demarcated and surrounded by fibrous connective tissue with area s of infiltration (Fig. 4). Areas of necrosis and hemorragic infarction were also noted. An accurate immunohistochemical study showed that the cellular elements were strongly positive for cytokeratin, which is consistent with features of typical epithelial cells, but negative for vimentin, S-100 protein, and smooth muscle actin. Furthermore, the weak positivity towards PCNA and MIB-I (1-5% of the nuclei were positive) suggested a low grade malignancy of the tumor.
found in Warthin's tumor, cystadenoma and its malignant variant, acinic cell adenocarcinoma, mucoepidermoid carcinoma, and polymorphous low-grade adenocarcinoma. Nevertheless, ductal papillomas constitute a separate category for their distinctive clinical and morphological features ; they are quite rare and typically occur in the minor salivary glands . To date, only three cases of papilloma of the parotid gland have been reported. The first case was described by Abrams and Finck [1J, who reported a rare large neoplasm (7.5 em greatest diameter) involving the parotid gland and extending through the overlying skin. It consisted of numerous papillary projections covered by an edematous squamous epithelium with no signs of dysplasia, while the deeper papillary surfaces were covered by an eosinophilic columnar epithelium alternating with differentiated mucous cells. The authors called this neoplasm "sial adenoma papilliferum" due to its similarity with the syringadenoma of the scalp. The second case was reported by Gardiner and colleagues [3J, who defined the term "inverted ductal papilloma" of the parotid gland. The neoplasm showed a marked proliferation of mostly uniform squamous cells, with no cellular atypia or keratinization. Such cellular proliferation determined the formation of pseudo lobular structures
Discussion A morphologic papillary-type pattern is a common feature of numerous salivary gland tumors. It can be
256 . L. Caramanico et al.
invaginating into the adjacent connective tissue stroma around wide cystic spaces. No mitotic figures were observed. The third and most recent case was described by King and Hill [4J , who reported a well-circumscribed parotid tumor in an 87-year-old man. Microscopically, the tumor had a papillary architecture lined by a double layer of cells: the inner layer was made up of cells with abundant clear cytoplasm and vesicular nuclei with prominent nucleoli , while the outer layer consisted of smaller cells with scanty acidophilic cytoplasm and dark nuclei. Also, in this case there was no evidence of mitotic activity, nuclear atypia or capsular invasion. The authors interpreted this tumor as "intraductal papilloma." The case presented here has some particularities: the papillary configuration was evident, which led us to consider a simple papilloma of the parotid gland, a rare tumor. However, characteristically, the epithelial cells lining the papillae showed in some areas a squamoustype differentiation, while in others we noticed a transitional structure that was very similar to the bladder epithelium, without any columnar epithelium covering the papillary projections, which, in contrast, is described in the inverted ductal papillomas. These features, which are unusual for salivary glands, and the clinical biological behavior of this neoplasm closely resembled neoplastic lesions of the bladder, according to our grading system. Nevertheless , as in other non-transitional epithelial cells, it can be hypothesized that an incomplete mal-
pighian metaplasia occurred in this histologic presentation. Furthermore, even if our case appears to be a salivary gland papilloma, it shares some unique characteristics with the cellular pleomorphism, the invasive growth pattern, and the pattern of the immunohi stochemical proliferation markers that led us to classify this neoplasm among the low-grade malignancy salivary gland lesions. In conclusion, this appears to be the first case of salivary gland, bladder-like low-grade papillary carcinoma.
References 1. Abrams AM, Finck FM (1969) Sialadenoma papilliferum. A previously unreported salivary gland tumor. Cancer 24: 1057-1063 2. Ellis GL, Auclair PL (1996) Ductal papilloma. (Tumours of the salivary glands.)AFIP: 120-130. 3. Gardiner GW, Briant TD, Sheman L (1984) Inverted ductal papilloma of the parotid gland. J Otolaryngolog y 13: 23- 26 4. King PH, Hill J (1993) Intraductal papilloma of parotid gland. J Clin Pathol46: 175-176 5. Ellis GL, Auclair PL (1996) Classification. (Tumor of the salivary glands.) AFIP: 27-29
Received: September 10, 1998 Accepted in revised version: February 12, 1999