Malignant Warthin''s tumour: a case study

Malignant transformation of a benign Warthin's tumour (adenolymphoma) is extremely rare. The light microscopic and ultrastructural features of an adenocarcinoma arising in a Warthin's tumour in the parotid gland are described. Light microscopy demonstrated a transition zone from the benign to the malignant component, and the malignant cells revealed oncocytic features by both light- and electronmicroscopy.     

Oncocytic adenocarcinoma arising in Warthin's tumor

Warthin's tumor (adenolymphoma) is a monomorphous adenoma of the salivary glands well characterized histologically. Its clinical evolution is almost invariably benign, the malignant change being extremely unusual. We present the case of a 67 year-old man with a right retromandibular tumor which has evolved over a two year period, with peripheral involvement of V, VI and VII cranial nerves on the same side, and direct invasion of intracranial structures. The biopsy revealed a classic adenolymphoma which shows foci of well differentiated adenocarcinoma. Transitional areas between benign and malignant epithelium were evident. In addition, histological findings support the hypothesis of the origin of adenolymphoma from epithelial ducts trapped in the regional lymphatic tissue.     

腮腺腺淋巴瘤的临床病理研究

目的：探讨腮腺腺淋巴瘤的临床病理特点。方法：收集并分析26例腮腺腺淋巴瘤病例资料,研究其临床特点、病理形态学特征,并复习相关文献。结果：男性21例,女性5例,年龄45~78岁,平均年龄61.3岁。临床均表现为腮腺区无痛性缓慢生长的肿物,界限清楚;肉眼呈分叶状,包膜大多完整,质中,切面灰白灰褐色,可见囊腔;镜下可见嗜酸性上皮细胞和反应性淋巴细胞,上皮多呈乳头状排列,间质为淋巴细胞。结论：腮腺腺淋巴瘤为良性肿瘤,临床少见,多位于腮腺后下极,大多为单灶,多见于老年男性,吸烟为其诱因,可根据其独特的病理学特征明确诊断。     

Malignant lymphoepithelial lesion

A case of undifferentiated carcinoma arising from benign lymphoepithelial lesion (BLEL) of the parotid gland was studied by light and electron microscopy. Histopathologically, the carcinoma was composed of pleomorphic anaplastic cells showing an undifferentiated type among abundant lymphoid tissue forming germinal center. Among the prominent lymphoid tissue, epithelial hyperplasia, dysplasia, and squamous metaplasia of the duct epithelium were found. Dysplastic epithelium revealed a transition with carcinomatous component in some areas. On the electron microscopic observation, the tumor cells were poorly differentiated, possessing desmosomes and intracytoplasmic filaments. The patient is alive and well 2 months after resection of the tumor, but has a high titer of serum Epstein-Barr virus capsid antigen in IgG. Eighty five cases of the malignant lymphoepithelial lesion (MLEL) including the present case are summarized.     

MALIGNANT LYMPHOEPITHELIAL LESION

A case of undifferentiated carcinoma arising from benign lymphoepithelial lesion (BLEL) of the parotid gland was studied by light and electron microscopy. Histopathologically, the carcinoma was composed of pleomorphic anaplastic cells showing an undifferentiated type among abundant lymphoid tissue forming germinal center. Among the prominent lymphoid tissue, epithelial hyperplasia, dysplasia, and squamous metaplasia of the duct epithelium were found. Dysplastic epithelium revealed a transition with carcinomatous component in some areas. On the electron microscopic observation, the tumor cells were poorly differentiated, possessing desmosomes and intracytoplasmic filaments. The patient is alive and well 2 months after resection of the tumor, but has a high titer of serum Epstein-Barr virus capsid antigen in IgG. Eighty five cases of the malignant lymphoepithelial lesion (MLEL) including the present case are summarized.     

Lymphoma arising in an adenolymphoma

A malignant lymphoma that originated in association with an adenolymphoma (Warthin's tumor) of the parotid salivary gland is reported. The occurrence of lymphomas in salivary glands is discussed briefly.     

Undifferentiated carcinoma of the salivary gland in Greenlandic Eskimos: demonstration of Epstein-Barr virus DNA by in situ nucleic acid hybridization.

Paraffin sections of 11 undifferentiated salivary gland carcinomas of lymphoepithelioma type (malignant lymphoepithelial lesion) arising in Greenlandic Eskimos (Inuit) were examined for the presence of Epstein-Barr virus (EBV) using in situ nucleic acid hybridization with a 35S-labeled EBV-specific probe. Epstein-Barr virus genomes were detected in each case in malignant epithelial cells, but were not found in lymphoid stroma or in residual benign salivary epithelium. Eight undifferentiated salivary gland carcinomas from non-Eskimo patients (including two with lymphoepithelioma-like features) were negative for EBV-DNA. Our results confirm the existence of a consistent and specific association between EBV and tumor cells of undifferentiated salivary gland carcinoma of lymphoepithelioma type arising in Greenlandic Eskimos.     

Ultrastructural criteria of malignancy of adrenal medullary tumor

Histological analysis and electron microscopy of 12 benign pheochromocytomas and 9 malignant pheochromoblastomas showed that there are no reliable histological differences between cells of benign and malignant tumor of the adrenal medulla. The ratio of ultrastructurally differentiated and undifferentiated cells in the tumor can reflect their maturity; the more ultrastructurally undifferentiated and less differentiated cells in the tumor, the higher is the malignant potential of this tumor.     

Malignancies arising in oncocytic schneiderian papillomas: a report of 2 cases and review of the literature

Oncocytic schneiderian papillomas (OSPs) are uncommon benign neoplasms that arise from the sinonasal schneiderian epithelium. Malignancies arising in OSPs are rare, and, to our knowledge, only 14 such instances have been reported in the medical literature. We report 2 additional cases--a small cell carcinoma and a sinonasal undifferentiated carcinoma arising in OSPs and presenting synchronously with the benign neoplasm. The potential for malignant transformation in OSPs is small, but warrants that these papillomas be completely excised to exclude a coexisting carcinoma.     

UNDIFFERENTIATED CARCINOMA OF THE THYROID GLAND WITH OSTEOCLAST-LIKE GIANT CELLS

Three cases of undifferentiated carcinoma of the thyroid gland with osteoclast-like giant cells resembling those of giant-cell tumor of bone are presented. The clinical and morphologic characteristics of these cases are described and the literature concerning these tumors is reviewed. The lesions occur in elderly people, grow rapidly and are fatal, as do the usual undifferentiated carcinomas of the thyroid gland. Nevertheless, the tumors differ histologically from the usual undifferentiated carcinoma of giant cell or spindle cell type in having the osteoclast-like giant cells with many, small, uniform, benign appearing nuclei. All three tumors contained partial areas of moderately to well differentiated carcinoma; papillary carcinoma in two, and follicular carcinoma in one. Although the histogenesis of the osteoclast-like multinucleated giant cells is not definitely established, it is proposed that the giant cells are reactive in nature and histiocytic in origin because of their benign appearance, phagocytic activity, high level of acid-phosphatase activity, and some ultrastructural features and that they are formed by fusion of mononucleated histiocytes.     

Mucoepidermoid carcinoma arising in Warthin's tumor of the parotid gland

Malignant transformation of Warthin's tumor is extremely rare, although it is the second most common benign tumor of the parotid gland. We describe our experience of mucoepidermoid carcinoma arising in Warthin's tumor of the parotid gland in a 64-year-old man. He had a swelling in the left parotid-masseteric region. The removed tumor was well encapsulated and histopathologically comprised Warthin's tumor and low-grade mucoepidermoid carcinoma. The mucoepidermoid carcinoma infiltrated lymphoid stroma of the Warthin's tumor, but capsular invasion is not found. Considering the clinical course and physical examination, the lesion was diagnosed as mucoepidermoid carcinoma arising in Warthin's tumor because its features filled the criteria of malignant transformation of Warthin's tumor. There has been no recurrence or distant metastasis for 19 months. Histological change from Warthin's tumor to mucoepidermoid carcinoma may be implicated in squamous or goblet cell metaplasia of epithelial cells. It is considered that the neoplastic cells of Warthin's tumor acquire malignant genotypes simultaneously with this dual differentiation.     

Malignant eccrine spiradenoma: a case report with pulmonary metastasis

Malignant eccrine spiradenoma is an extremely rare sweat gland tumor. It may develop de novo or arise in pre-existing benign eccrine spiradenoma. However, most tumors are presented in the latter mode. The case of a 50-year-old man with malignant transformation from previously existing benign eccrine spiradenoma over his right lateral thigh is reported. Evidence for this diagnosis includes two distinct morphological components. One is the well demarcated, small round to oval benign eccrine spiradenoma and the other is the malignant element with sarcomatoid differentiation. Some foci of transition between the benign eccrine spiradenoma and the sarcomatoid part are evident and represents that the latter may arise from the former. Whether different morphological patterns influence the patients' outcome is still doubtful. However, the malignant eccrine spiradenoma is thought to have the capacity of metastasis and lethal potentiality.     

Undifferentiated sarcoma of the parotid gland with osseous metaplasia

Malignant spindle cell tumors of the parotid gland are a diagnostic challenge. We present an unusual case of such a tumor that occurred in the right parotid gland of a 53-year-old man. The clinical and histologic assessments were consistent with a primary sarcoma of the parotid gland. The tumor was composed of sheets of pleomorphic, spindle-shaped cells with an area of bone formation. By immunohistochemistry, the tumor cells were positive for vimentin and negative for epithelial markers. Electron microscopy revealed mesenchymal cells containing moderate amounts of rough endoplasmic reticulum. The major differential diagnostic considerations were spindle cell carcinoma, carcinosarcoma, and primary undifferentiated sarcoma with osseous metaplasia. The lack of epithelial features and the benign appearance of the bone formation led to a diagnosis of undifferentiated sarcoma of the parotid gland.     

Intraductal papillary tumors of the major salivary glands: case reports of benign and malignant variants

Intraductal papilloma is an extremely rare benign salivary gland tumor that occurs most commonly in the minor salivary glands. To our knowledge, a malignant counterpart of intraductal papilloma has not been described previously. We report one case each of benign and malignant intraductal papillary tumors. The benign tumor occurred in the sublingual gland and was a typical example of intraductal papilloma, with the exception that we found no previously published reports of this type of tumor in this location. The other patient had a left parotid gland tumor that was architecturally similar to the intraductal papilloma, with the addition of cytologic atypia, intraductal extension, microinvasion, and lymph node metastases. This tumor was diagnosed as intraductal papillary adenocarcinoma with an invasive component. Both patients were alive and well without evidence of recurrence 2 years and 6 months (case 1) and 6 years (case 2) after surgery. Immunohistochemical examination revealed that the tumor cells resembled duct luminal cells in both cases. The 2 tumors had different immunoreactivities for carcinoembryonic antigen, p53, and Ki-67. The malignant counterpart of intraductal papilloma should be considered in the differential diagnosis of salivary gland tumors with a predominantly papillary structure, even though this tumor is extremely rare.     

Myoepithelial Carcinoma Arising in a Benign Myoepithelioma: Immunohistochemical, Ultrastructural, and Flow-Cytometrical Study

A case of myoepithelial carcinoma arising in a benign myoepithelioma of the minor salivary gland in a 71-year-old patient is reported. The tumor presented initially on the palate and had been diagnosed as “benign lesion” 40 years before. It recurred 22, 36, and 40 years after initial presentation, and a similar histopathological diagnosis was rendered. One year after the last recurrence, the tumor recurred showing typical changes of malignant transformation, and the diagnosis was malignant myoepithelioma. The light microscopy and ultra-structural features of the initial tumor were typical of plasmocytoid myoepithelioma. There were abundant round cells and rare spindle cells with uniform dispersed filaments, sometimes arranged in parallel streams without evidence of dense bodies. These cells showed micropinocytotic vesicles along the cell membrane with poorly developed intercellular junctions and were surrounded by a basal membrane. The malignant counterpart showed fewer plasmocytoid cells and a rather epithelial pattern with marked nuclear pleomorphism and formation of small, or rarely large, glandular lumina. The immunohistochemical features were similar for the benign and malignant tumors, with positivity for S-100 protein, vi-mentin, cytokeratins, and CAM 5.2, and were negative for GFAP, muscle-specific actin, CEA, and desmin. Flow cytometry showed a change in the DNA content profile. The benign myoepithelioma had a diploid DNA content with a low S-phase fraction of 3.9% and proliferative index of 9.1%, while the myoepithelial carcinoma had an evident aneuploid DNA stem line and an increased S-phase fraction of 8.3% with a proliferative index of 18.1%.     

Mixed epithelial and stromal tumor of kidney with malignant transformation: report of two cases and review of literature

We present 2 cases of mixed epithelial and stromal tumor of the kidney with sarcomatous transformation. One patient was a 53-year-old woman who presented with macroscopic hematuria. The resected tumor involved the right renal parenchyma, measuring 13.0 x 8.0 x 4.0 cm, and extended to perirenal adipose tissue. The second patient was a 56-year-old woman who presented with right flank colic pain. The tumor measured 6.0 x 5.5 x 4.0 cm, with an intact capsule at the upper pole. Both tumors showed a well-circumscribed, multilocular, cystic, and focally solid mass. Sections of both tumors revealed benign and malignant components. The benign component consisted of multilocular cysts and fibrous stroma with a focally ovarian stromalike component. The malignant component in both cases was predominantly composed of undifferentiated cellular spindle cell sarcoma with frequent mitoses. One case showed additional heterologous malignant elements, including rhabdomyosarcomatous, chondrosarcomatous, and focal carcinomatous components. We report 2 additional cases of sarcomatous transformation in mixed epithelial and stromal tumor of the kidney.     

UNDIFFERENTIATED CARCINOMA OF THE PAROTID GLAND WITH BIZARRE GIANT CELLS

A rare autopsy case of undifferentiated carcinoma of the parotid gland with bizarre giant cells is reported. Grossly, the tumor was fist-sized, firm, solid, grayish-white in color, and was not encapsulated, with a bean-sized ulceration on the skin. Microscopical examination revealed undifferentiated carcinoma of the parotid gland composed of bizarre giant cells, large tumor cells, and spindle cells in part. Ultrastructural examination, recovered from formalin-fixed material, disclosed filamentous structure in some large tumor cells. It is strongly suggested that myoepithelial cells played an important role in the development of the undifferentiated carcinoma of the parotid gland. The clinical and histopathological characteristics of this case is described, and the literature concerning undifferentiated carcinoma of the parotid gland is reviewed.     

Mammary analog secretory carcinoma of salivary gland with high-grade histology arising in hard palate,report of a case and review of literature

Mammary gland analog secretary carcinoma (MASC) of salivary gland is typically a tumor of low histologic grade and behaves as a low-grade malignancy with relatively benign course. This tumor shares histologic features, immunohistochemical profile, and a highly specific genetic translocation, ETV6-NTRK3, with secretory carcinoma of breast. Histologically, it is often mistaken as acinic cell carcinoma, adenocarcinoma not otherwise specified, and other primary salivary gland tumors. Here we report a case of MASC with high-grade transformation and cervical lymph node metastases confirmed with ETV6-NTRK3 translocation arising in the hard palate of a 41 year-old adult. Interestingly, the metastatic carcinoma has lower grade than the original tumor which strongly support malignant transformation of the original tumor. Most commonly, MASC arises from the parotid gland and less often in minor salivary glands. Metastasis is relatively uncommon and high-grade histology has only been reported in four cases with three of them arising from the parotid gland and the location of the fourth one has not been reported. This is the first case with high grade histology that arise from minor salivary gland and it emphasizes the importance of molecular screening of salivary gland tumor with high-grade histology for ETV6-NTRK3 translocation. In our literature of 115 cases that includes the current case, MASC occurred predominantly in adult with only a few cases under 18 years of age and a male to female ratio of 1.2:1. Parotid gland is more commonly affected but there is also significant occurrence in minor salivary glands. Except for the cases with high grade histology, the overall prognosis is good.     

Multiple reciprocal translocations in salivary gland mucoepidermoid carcinomas

Mucoepidermoid carcinoma, the most common human malignant salivary gland tumor, can arise from both major and minor salivary glands, including sites within the pulmonary tracheobronchial tree. We performed comparative genomic hybridization (CGH) and spectral karyotyping (SKY) on two tumor cell lines: H3118, derived from tumor originating in the parotid gland, and H292, from tumor in the lung. In both cell lines, CGH showed a partial gain within the short arm of chromosome 7 and SKY revealed the presence of the previously reported reciprocal translocation t(11;19)(q21;p12). Additional chromosomal rearrangements were found in both cell lines, including three more reciprocal translocations in cell line H292 [t(1;16), t(6;8)x2] and three other reciprocal translocations in cell line H3118 [t(1;7), t(3;15), and t(7;15)]. A review of the literature of other reported cases of mucoepidermoid carcinomas analyzed with standard G-banding techniques, as well as distinct benign salivary gland tumors, such as pleomorphic adenomas and Warthin tumor, confirmed the presence of a karyotype dominated by reciprocal translocations. Four chromosomal bands were involved in chromosomal translocations in both cell lines: 1q32, 5p15, 7q22, and 15q22. Fluorescence in situ hybridization studies showed that the breakpoints in these four bands were often within a few megabases of each other. The involvement of similar chromosomal bands in breakpoints in these two cell lines suggests that these regions may be predisposed or selected for chromosomal rearrangements in this tumor type. The presence of multiple reciprocal translocations in both benign and malignant salivary gland tumors may also suggest a particular mechanism within mucous or serous glands mediating chromosomal rearrangements.     

Primitive neuroectodermal tumor of prostate

Primitive neuroectodermal tumors (PNETs) are malignant proliferations of small, undifferentiated neuroectodermal cells occurring mainly in children and share the same reciprocal translocation between chromosomes 11 and 22 and the same patterns of biochemical and oncogene expression as osseus and extraosseus Ewing's sarcoma. Some PNETs occur in the brain, while others (the peripheral PNETs) occur in sites outside the brain, such as in the extremities, pelvis and the chest wall. They mostly originate in the chest, pelvis and retroperitoneum; in rare cases, occurrence in the head and neck area has also been seen. We present a rare case of primitive neuroectodermal tumor arising in the prostate gland in a 25-year-old male. To the best of our knowledge, this is the first documentation of a primary peripheral primitive neuroectodermal tumor in the prostate gland of any patient from India and rarely reported in English literature.