Myoepithelial carcinoma arising in a pleomorphic adenoma of the parotid gland: report of a case with cytopathologic findings

BACKGROUND: Carcinoma arising in a mixed tumor, or carcinoma ex pleomorphic adenoma (CEPA), is an uncommon primary salivary gland neoplasm. Among the various types of carcinomas that can be seen histologically in a CEPA, myoepithelial carcinoma is one of the rarest forms. CASE: A 76-year-old woman presented with an incidental parotid/parapharyngeal mass. Computed tomography-guide fine needle aspiration (FNA) showed a biphasic neoplasm with epithelial and stromal components consistent with pleomorphic adenoma (PA). However, in addition, a distinct population of discohesive atypical and pleomorphic cells with high nuclear/cytoplasmic ratio was noted in the background. In the cytopathologic diagnosis a suspicion was raised about a possible CEPA. Subsequent resection of the parotid mass confirmed the presence of low grade myoepithelial carcinoma arising in a PA. CONCLUSION: Although uncommon, CEPA should be suspected on FNA when atypical cytomorphologic characteristics are observed. In rare cases a myoepithelial carcinoma also arises in a preexisting PA, necessitating an accurate interpretation for more definitive therapy.     

Fine needle aspiration cytology of epithelial-myoepithelial carcinoma of salivary glands. A report of three cases.

BACKGROUND: Epithelial-myoepithelial carcinoma is a rare, low grade malignant tumor of the salivary glands. Histologically, it has a biphasic cellular composition and exhibits a high degree of differentiation. The fine needle aspiration cytology of this rare tumor is rarely described in the literature. CASES: We report the fine needle aspiration cytology of three epithelial-myoepithelial carcinomas, arising in the right parotid, left parotid and minor salivary gland of the hard palate. Cytology showed a biphasic population consisting of cells of ductal epithelial and myoepithelial origin arranged in small clusters and sheets. The myoepithelial cells had small, uniform nuclei; ample, clear cytoplasm and distinct cell borders, while the ductal epithelial cells had larger, mildly pleomorphic nuclei and scanty cytoplasm. These ductal cells tended to form tubules among background sheets of clear myoepithelial cells. This feature, if present, was an important diagnostic clue. Hyaline material surrounding cell clusters and focal adenoid cystic carcinoma-like areas with orangeophilic globules were also not uncommon. CONCLUSION: While the cytologic appearance of epithelial-myoepithelial carcinoma may closely mimic that of other salivary gland tumors, such as adenoid cystic carcinoma, pleomorphic adenoma and basal cell adenoma, certain peculiar cytologic features may allow a distinction to be made on fine needle aspiration biopsy.     

Epithelial myoepithelial carcinoma of the parotid gland with malignant ductal and myoepithelial components arising in a pleomorphic adenoma: a case report with cytologic, histologic and immunohistochemical correlation

BACKGROUND: To describe the cytologic, histologic and immunohistochemical findings of a case of epithelial myoepithelial carcinoma (EMC) arising from a pleomorphic adenoma (PA) of the parotid with both malignant epithelial and myoepithelial components. CASE: A 29-year-old female presented with a 1.5 x 1.5-cm, palpable mass of the left parotid of 7-8 months' duration with recent enlargement and pain. Fine needle aspiration biopsy (FNAB) revealed biphasic epithelial (small cell) and myoepithelial (large/clear cell) clusters arranged in a pseudopapillary and trabecular pattern with abundant hyaline material with many naked nuclei, together with areas typical of pleomorphic adenoma (PA) was noted. The cytology was reported as salivary gland neoplasm, "suggestive of adenoid cystic carcinoma, less likely pleomorphic adenoma." The mass was excised and histologically reported as "pleomorphic adenoma, with focal invasion of one resected margin." Four months later the tumor recurred, and FNAB showed almost the same cytologic features as did the previous aspirate. Due to early recurrence, previous histologic sections were reviewed, and typical areas of a biphasic pattern of EMC with atypicality and mitosis of both components was found. The final diagnosis was EMC ex PA. CONCLUSION: Although previous reports mention the difficulties in diagnosing EMC and differentiation from the more common salivary gland neoplasms such as PA, we like to emphasize the cytologic confusion that results when the tumors coexist.     

Cytomorphologic features of a polymorphous low grade adenocarcinoma of the palate. A report of 2 cases with immunocytochemistry

BACKGROUND: Polymorphous low grade adenocarcinoma (PLGA) is a histologically low grade tumor of minor salivary gland origin. It is important to differentiate PLGA from other salivary gland tumors with myoepithelial differentiation, such as pleomorphic adenoma, adenoid cystic carcinoma and epithelial myoepithelial carcinoma. Here we report 2 cases of PLGA originating in the palate and describe the cytomorphologic and immunocytochemical features. CASES: The patients were a 55-year-old woman and a 63-year-old man. Both presented with a mass in the palate. Clinically the mass appeared malignant, and resection was performed. Cytologically the tumor cells were composed of sheet clusters, pseudopapillary epithelial clusters, naked cells and stromal components. Immunocytochemically the tumor cells showed strong expression of carcinoembryonic antigen (CEA) and vimentin. CONCLUSION: PLGA may be difficult to distinguish from other salivary gland tumors with myoepithelial differentiation. However, the cytopathologist should be aware of the distinctive cytomorphologic features of PLGA, demonstrating immunopositivity to CEA and vimentin.     

Polymorphous low grade adenocarcinoma of the salivary gland. Diagnosis by fine needle aspiration cytology

OBJECTIVE: To describe the fine needle aspiration cytology findings of polymorphous low grade adenocarcinoma of the salivary gland. STUDY DESIGN: The authors reviewed the cytologic findings of 5 cases of polymorphous low grade adenocarcinoma. All cases were confirmed by histologic examination. RESULTS: All cases showed similar cytologic findings. The smears had high cellularity with a population of mixed epithelial and myoepithelial cells. These cells formed branching papillae, sheets and clusters. The epithelial cells were uniform, with round to ovoid nuclei; absent or inconspicuous nucleoli; and a moderate amount of dense cytoplasm. Occasionally the cells formed spherical structures containing hyaline globules. Myxoid matrix, either dispersed in the background or interspersed with the cellular elements, was also seen often. CONCLUSION: Polymorphous low grade adenocarcinoma should be cytologically differentiated from adenoid cystic carcinoma, monomorphic adenoma and pleomorphic adenoma. Recognition of subtle cytologic features. may be useful in the differential diagnosis.     

Glial fibrillary acidic protein and desmin in salivary neoplasms. Expression of four different types of intermediate filament proteins within the same cell type

The presence of intermediate filament proteins (IFP) in normal salivary gland tissue and investigated by immunohistochemical techniques on frozen sections. Cytokeratins (CKs) were seen in almost all normal epithelial cells. In the parotid gland and in palatal gland tissue, a co-expression of cytokeratin and glial fibrillary acidic protein (GFAP) was seen in some myoepithelial cells, but this was not apparent in the submandibular gland. In some pleomorphic adenomas, carcinomas in pleomorphic adenomas, one mucoepidermoid carcinoma, one mucus-producing adenopapillary carcinoma and one adenoid cystic carcinoma, cells expressing three different IFP classes were found (CKs, vimentin, GFAP). These cells were most often situated peripherally in the tumour cords or ducts. The cytokeratin pattern in these cells, as revealed by mAbs PKK1-3, was similar to that in normal myoepithelial cells. Furthermore, reactivity for a fourth class of IFP, desmin, could be seen in this cell type in two carcinomas in pleomorphic adenomas, and also in a few cells in a pleomorphic adenoma and an adenoid cystic carcinoma. Thus the pattern of IFP expression in salivary gland neoplasms, is very complex, and cannot always be related to the normal tissue.     

Diagnosis of pleomorphic adenoma in a heterotopic salivary gland: a case report

BACKGROUND: The histologic diversity encountered in pleomorphic adenoma may cause diagnostic difficulty in fine needle aspiration cytology (FNA) due to limited and selective sampling. CASE: A 40-year-old woman presented with a mass in the anterior aspect of the neck along the sternocleidomastoid muscle. FNA revealed a cellular tumor with a chondrimyxoid background and epithelial cells intermingled with a few mesenchymal cells. The diagnosis of pleomorphic adenoma was confirmed on histopathology. CONCLUSION: Primary ectopic pleomorphic adenoma can confidently be diagnosed by FNA. This technique is a useful tool in the initial assessment of the tumor.     

Glial fibrillary acidic protein and desmin in salivary neoplasms

The presence of intermediate filament proteins (IFP) in normal salivary gland tissue and in a number of salivary gland neoplasms has been investigated by immunohistochemical techniques on frozen sections. Cytokeratins (CKs) were seen in almost all normal epithelial cells. In the parotid gland and in palatal gland tissue, a co-expression of cytokeratin and glial fibrillary acidic protein (GFAP) was seen in some myoepithelial cells, but this was not apparent in the submandibular gland. In some pleomorphic adenomas, carcinomas in pleomorphic adenomas, one mucoepidermoid carcinoma, one mucus-producing adenopapillary carcinoma and one adenoid cystic carcinoma, cells expressing three different IFP classes were found (CKs, vimentin, GFAP). These cells were most often situated peripherally in the tumour cords or ducts. The cytokeratin pattern in these cells, as revealed by mAbs PKK1-3, was similar to that in normal myoepithelial cells. Furthermore, reactivity for a fourth class of IFP, desmin, could be seen in this cell type in two carcinomas in pleomorphic adenomas, and also in a few cells in a pleomorphic adenoma and an adenoid cystic carcinoma. Thus the pattern of IFP expression in salivary gland neoplasms, is very complex, and cannot always be related to the normal tissue.     

Metastatic carcinoma with myxoid stroma in the salivary gland: a case report

BACKGROUND: Most epithelial salivary gland tumors with a myxoid stroma are pleomorphic adenomas. Rare metastatic carcinomas have prominent myxoid stroma and therefore can mimic pleomorphic adenomas cytologically. CASE: A 62-year-old man presented with a left canthal tumor. A biopsy and computed tomography revealed an adenocarcinoma of the left ethmoid sinus with medial canthal extension. The patient was treated with tumor resection and chemoradiation. An enlarging, left parotid mass developed that was reported as a pleomorphic adenoma on a fine needle aspirate. However, a parotidectomy showed metastatic adenocarcinoma with a myxoid and fibroblastic stroma in an intraparotid lymph node. CONCLUSION: Before concluding cytologically that a biphasic epithelial/myxoid stromal salivary gland lesion is a pleomorphic adenoma, the patient's previous malignancies should be reviewed, and the smears should be scrutinizedfor the absence of diffuse epithelial atypia and presence of spindle cells transitional between the 2 tissue phases.     

Cytologic findings of a pleomorphic adenoma of the breast: a case report

BACKGROUND: Pleomorphic adenoma of the breast is a rare benign tumor. Only a few cases have been reported. The histologic features have been described well. However, the cytologic findings have been described in only a few papers. CASE: A 47-year-old female presented with a left breast mass of several months' duration. The clinical and mammographic findings were highly suspicious for malignancy. Following an aspiration biopsy diagnosis of "positive for malignancy," the mass was excised. The histologic diagnosis was pleomorphic adenoma (mixed tumor of salivary gland type) rather than carcinoma. CONCLUSION: The cytologic presentation of pleomorphic adenoma of the breast can masquerade as that of a malignant tumor, in this case colloid carcinoma. This case delineates the cytomorphologicfeatures of pleomorphic adenoma, which may mimic carcinoma.     

Malignant fibrous histiocytoma,giant cell type,of the breast mimicking metaplastic carcinoma. A case report

BACKGROUND: We report a case of malignant fibrous histiocytoma, giant cell type (MFHGC), of the breast. A review of the literature failed to reveal cytology-based reports on this entity. The cytologic similarity of breast MFHGC on fine needle aspiration biopsy (FNAB) to other malignant breast neoplasms, including carcinoma with osteoclastlike giant cells, metaplastic carcinoma and breast sarcomas, as well as benign reactive processes, makes the recognition of this tumor challenging. CASE: A 72-year-old woman presented with a 5-month history of an enlarging breast mass. FNAB of the mass showed a hypercellular smear composed of cohesive, branching clusters of spindle cells with ovoid, focally hyperchromatic nuclei and inconspicuous nucleoli. Interspersed osteoclastlike giant cells, some associated with clusters of spindle cells, were uniformly seen throughout the smear. The background was hemorrhagic, with cellular debris and occasional spindle cells and lymphocytes. No ductal epithelial or myoepithelial cells were seen. An incisional biopsy was performed, followed by radical mastectomy. The histologic examination was diagnostic of MFHGC. The diagnosis was supported by immunohistochemical and electron microscopic studies. CONCLUSION: MFHGC, also called primary giant cell tumor of soft tissues, is composed of a mixture of histiocytes, fibroblasts and bland-appearing osteoclastlike giant cells with a multinodular growth pattern. Although MFHGC rarely occurs in the breast and the definitive diagnosis is difficult based on cytology alone, the diagnosis can be considered when a cytologic examination reveals a hypercellular, spindle cell smear with osteoclastlike giant cells in the absence of ductal epithelial or myoepithelial cells.     

Metastatic minor salivary gland colloid carcinoma in the parotid region after parotidectomy for pleomorphic adenoma: a case report

BACKGROUND: Primary colloid or mucinous carcinoma of the salivary glands is extremely rare. Only a few cases have been reported that originated in the minor salivary glands. an even more exceptional presentation is as a metastatic tumor in the parotid region subsequent to superficial parotidectomy for pleomorphic adenoma. The case presented here posed a diagnostic dilemma that could be resolved only after a thorough reevaluation of the previous cytologic and histologic material and detection of the occult primary tumor in the hypopharynx following an extensive clinical and radiologic workup. CASE: A 75-year-old female underwent fine needle aspiration of the left parotid and was diagnosed as having pleomorphic adenoma. A superficial parotidectomy removed the tumor completely, and the diagnosis was confirmed. Six months following the surgery, the patient developed an enlarged nodular mass in the ipsilateral parotid region, with fine needle aspiration showing colloid (mucinous) adenocarcinoma, which proved to be a metastatic colloid (mucinous) carcinoma on excisional biopsy. The clinical and radiologic workup in search of a primary lesion led to an occult tumor in the left hypopharyngeal mucosa. CONCLUSION: Unusual presentations of rare tumors can cause considerable diagnostic difficulties to both the clinician and cytopathologist. Awareness of these rarities is important to ensure the best patient care and to avoid unnecessary investigative and therapeutic procedures.     

Mixed osteoclastic/pleomorphic giant cell tumor of the pancreas: a case report

BACKGROUND: Mixed giant cell tumor (MGCT) of the pancreas is a rare malignant neoplasm. The tumor contains pleomorphic giant cells (PGC), pleomorphic mononuclear cells (PMC) and osteoclastic giant cells (OGC). We describe the first fine needle aspiration biopsy (FNAB) diagnosis of this tumor. CASE: A 76-year-old woman was discovered (on imaging studies) to have an apparently inoperable mass in the head of the pancreas. Computed tomography-guided FNAB showed a malignant neoplasm with features of an MGCT. PGC/PMC, OGC and spindle cells were present. The PGC/PMC expressed epithelial antigens, pancytokeratin, CAM 5.2, AE1/AE3 and epithelial membrane antigen (EMA). The spindle cells focally stained for EMA. OGC were negative for the epithelial antigens. OGC, PGC/PMC and the spindle cells were positive for the mesenchymal marker vimentin. CONCLUSION: FNAB was instrumental in making the diagnosis of a rare pancreatic tumor, MGCT. Immunocytochemistry was helpful in making a definitive diagnosis and suggested that MGCT is a carcinosarcoma like neoplasm. The morphology and immunocytochemical profile raise the possibility that osteoclastic giant cell tumor and pleomorphic giant cell tumor may be different morphologic and biologic expressions of the same tumor.     

Role of FNAC in metastasizing malignant mixed tumor of the external auditory canal. A case report

BACKGROUND: No previous report of metastasizing mixed tumor (pleomorphic adenoma) of the external auditory canal (EAC) has been described. CASE: A 12-year-old, Chinese girl with a history of mixed tumor of the EAC presented with a locally recurrent, aggressive tumor and metastases to the lung and bone five years later. The primary, locally recurrent and metastatic lung tumor showed epithelial and myoepithelial elements with duct formation, chondromyxoid stroma and mitotic activity in the cellular areas on histology. Fine needle aspiration cytology (FNAC) disclosed the presence of spindle cells blending into chondromyxoid fibrillar ground substance in the recurrent and metastatic lung tumors. CONCLUSION: In primary mixed tumor of the EAC, FNAC plays a useful role in the diagnosis of recurrent and metastatic disease. Its ability to identify ominous features, such as increased mitoses in this case, may be limited by sampling. Since cytology and histology cannot reliably prognosticate, long-term follow up of mixed tumor of the EAC after complete excision is advocated.     

Clear cell carcinoma arising from pleomorphic adenoma of a minor salivary gland: Report of a case with fine needle aspiration, histologic and immunohistochemical findings

BACKGROUND: Malignant changes in pleomorphic adenoma (PA) of the salivary gland (carcinoma ex pleomorphic adenoma) are not common. Clear cell carcinoma is a rare form of salivary gland tumor and involves mostly minor salivary glands, especially those of the palate. Only 3 cases of clear cell carcinoma arising in PA have been reported, 2 in submandibular glands and 1 in a minor salivary gland of the palate. CASE : A 53-year-old man presented with an enlarged mass on the left side of the palate. He had a history of palate mass about 30 years earlier; it was excised and reported as PA. Since then the tumor had recurred twice in the same place; it had been excised and was diagnosed as PA again. A few years later the mass showed rapid growth over a few months. Fine needle aspiration of the mass showed epithelial clusters with bland nuclear features and myxohyaline material typical of PA. Also noted were large and small papillary, trabecular and well-circumscribed clusters of neoplastic cells with a moderate amount offoamy, vacuolated cytoplasm with distinct borders. Glandlike and acinar structures with hyaline globule material resembling cannonballs were also noted. The cytology was suspicious for malignancy. Incisional biopsy was reported as PA. Due to the suspicion of malignancy, the whole mass was excised up to the floor of the orbit. The final diagnosis was clear cell carcinoma expleomorphic adenoma. CONCLUSION: Due to nonspecific cytologic findings in clear cell carcinoma and a mixture of elements of PA in this case, we did not consider clear cell carcinoma as the malignant component.     

Fine needle aspiration cytology of basal cell adenoma of the salivary gland

OBJECTIVE: To formulate cytologic features for differential diagnosis of basal cell adenoma (BCA). STUDY DESIGN: The usefulness of 5 items for a cytologically definitive diagnosis of BCA was examined. The 5 items in 8 BCA and 22 non-BCA cases (adenoid cystic carcinoma [ADCC], basal cell adenocarcinoma, myoepithelioma, pleomorphic adenoma and polymorphous low-grade adenocarcinoma) that displayed mimicking cytology were examined cytologically. RESULTS: The useful items were < 5.1 microm in mean of epithelial nuclear short diameter; mild atypia on definitive diagnosis; stromal cell cluster combining smooth margin surrounding the epithelial cell cluster or containing the epithelial cell cluster; epithelial clusters surrounded by or adhered to a thick, hyalinized smooth margin without stromal cluster; and closely fastened, tight clusters with denser cytoplasm than ADCC, but an indistinct border, with oval nuclei and no hyaline cells. CONCLUSION: Five items are useful criteria for BCA.     

Extramedullary plasmacytoma of the parotid gland. Report of a case with extensive amyloid deposition masking the cytologic and histopathologic picture

BACKGROUND: Extramedullary plasmacytomas are uncommon. Although approximately 90% occur in the head and neck region, parotid gland localization is extremely rare. CASE: This report describes fine needle aspiration and histopathologic findings in an extramedullary plasmacytoma arising in the left parotid gland of a 62-year-old man. Aspiration smears showed multiple amorphous clumps of material admixed with ductal epithelial cells, multinucleated giant cells and inflammatory cells rich in plasma cells, suggestive of pleomorphic adenoma. In surgical material, excessive amyloid deposition was observed. Six months later the tumor recurred, and in the second surgical specimen clusters of atypical plasma cells among amyloid deposits was noted. Clinical and laboratory examination excluded multiple myeloma. After local recurrence, radiotherapy was applied. Ten months later the patient was well and without systemic involvement. CONCLUSION: Two points are important. First, in the salivary gland region, because of the focal metachromasia of amyloid with Giemsa stain, amyloid can be confused with the chondromyxoid matrix of pleomorphic adenoma. Second, although localized forms of amyloid tumor exist, one should keep in mind that amyloid may be so abundant that it may mask an underlying plasma cell neoplasm, as in our case.     

Cytomorphologic spectrum of carcinoma ex pleomorphic adenoma

OBJECTIVE: To delineate the cytomorphologic features of carcinoma ex pleomorphic adenoma (CPA) and identify the diagnostic pitfalls. STUDY DESIGN: Smears of 14 cases suspected as CPA on fine needle aspiration over a period of 15 years were reviewed. Cytohistologic correlation was done in 10 cases. RESULTS: All cases had a salivary gland mass of 1-16 years' duration, with a rapid increase in size in 10 cases. Epithelial cells predominated over stroma in 11 of 14 cases. Group I showed unequivocal malignant cells admixed with benign epithelial and stromal components of pleomorphic adenoma (PA), which were considered diagnostic of CPA on review. The cytologic differential diagnosis in these cases included mucoepidermoid carcinoma, carcinosarcoma and metastatic adenocarcinoma. Group II comprised 7 cases suspected to be cellular PA with atypia or CPA. These showed mild to moderate degrees of pleomorphism, absence of unequivocal malignant cells, and a variable proportion of benign epithelial and stromal components. Four of them were histologically confirmed as CPA. CONCLUSION: Sampling error is an important cause of diagnostic pitfalls. Correlation with clinical data is essential in diagnosis of CPA on cytology. In a proper clinical setting, extensive fine needle aspiration sampling should be done initially. Any degree of nuclear atypia in PA should be documented, alerting the clinician and histopathologist to the possibility of CPA.