CK7 expression in carcinomas of the Waldeyer's ring area

Primary carcinomas of the Waldeyer's ring area are typically nonkeratinizing squamous cell carcinomas (SCC). Their cervical lymph node metastases are not uncommonly cystic and filled with necrotic tumor cells. Some cysts, however, contain clear fluid. During the investigation of SCC producing "fluid-filled" cystic metastases, we evaluated hematoxylin and eosin (H&E) sections of 90 primary SCC for their site of origin. We analyzed the cytokeratin (CK) profile of primary and metastatic carcinoma with special focus on the expression of CK7, a putative marker for ductal differentiation. CK7 was expressed in submucosal minor salivary gland acini and ducts, but not in the squamous surface epithelium of the Waldeyer's ring. CK7 was expressed in 11 primary SCC (8 base of tongue/3 palatine tonsil). The CK7-positive SCC were deep-seated, arose from large excretory ducts of submucosal minor salivary glands, and showed only insignificant surface involvement. They were characterized by a solid infiltrative growth pattern of basaloid cells with focal ductal differentiation. Salivary ducts adjacent to the carcinoma showed extensive intraductal hyperplasia and metaplasia. All CK7-positive carcinomas produced CK7-positive cystic nodal metastases, most of which contained paucicellular fluid. No solid CK7-positive nodal metastases were identified. In summary, a subset of carcinomas occurring in the Waldeyer's ring area appear to arise from large excretory ducts of submucosal minor salivary glands with only limited surface involvement, express CK7, and produce CK7-positive cystic "fluid-filled" nodal metastases. The histomorphology and immunophenotype suggest that these carcinomas represent basaloid SCC arising from excretory ducts of the submucosal minor salivary glands.     

Basal cell adenoma with extensive squamous metaplasia and cellular atypia: a case report with cytohistopathological correlation and review of the literature

Basal cell adenoma (BCA) is a rare benign basaloid neoplasm of the salivary gland. There are four histopathological types of BCA: solid, tubular, trabecular, and membranous. It is known that focal squamous metaplasia may be seen in some BCAs, but it is rare to see extensive squamous metaplasia, especially with cellular atypia. Here, a 25-year-old male with right parotid swelling is presented. Ultrasonography revealed a 2-cm well defined mass in his parotid gland. Fine-needle aspiration (FNA), performed prior to surgical excision, showed a highly cellular tumor composed of basaloid cells, forming small duct-like or tubular structures containing basement membrane-like material, as well as squamous cells with hyperchromatic, enlarged, pleomorphic, and bizzare nuclei. We made a cytopathological diagnosis of "basaloid neoplasm" and also reported that the differential diagnosis included BCA, cellular pleomorphic adenoma, basal cell adenocarcinoma, and carcinoma ex pleomorphic adenoma. The patient underwent total parotidectomy. Both frozen and permanent sections showed a BCA with membranous, tubulotrabecular pattern, and extensive squamous metaplasia. Some of the squamous cells showed significant nuclear hyperchromasia, enlargement, and pleomorphism. As far as we know, this is the first case of BCA with extensive squamous metaplasia and prominent cellular atypia. This case has been presented to show that squamous metaplastic cells with hyperchromatic, enlarged, bizarre, and pleomorphic nuclei can be seen on FNA smears of a benign tumor like BCA. Also, the differential diagnosis of BCA of the salivary gland is discussed here.     

Salivary gland components involved in the formation of squamous metaplasia.

Squamous metaplasia is not an uncommon feature of a number of salivary gland lesions. Arterial ligation of rat submandibular and sublingual salivary glands was used for study of the processes and cell types involved in the development of the squamous metaplasia that occurs in ischemic and infarcted portions of gland parenchyma 6 to 8 days following vessel ligation. Light and electron micrographs show that the principal portion of salivary gland tissue undergoing squamous metaplasia is the acinar-intercalated duct cell complex. Early stages of this process involve a gradual dedifferentiation of acinar cells and hyperplasia of acinar, duct luminal cells, and myoepithelium. Subsequently, both luminal and myoepithelial cells have increasing accumulation of tonofilaments and formation of desmosomes, and centrally located cells may undergo keratinization. Immunohistochemical staining of ischemic salivary gland tissue with developing squamous metaplasia was performed with the use of rabbit antisera to human epidermal and Mallory body cytokeratins. The two antisera gave complementary patterns in normal acini and ducts, with antibody to epidermal cytokeratin (ECK) staining only myoepithelial cells and antibody to Mallory body cytokeratin (MBCK) staining mainly luminal epithelial cells. In early phases of squamous metaplasia (6 days after ligation), antibody to ECK stained central and peripheral (myoepithelial) cells, but by 8 days after ligation only central cells were stained. At 6 days after ligation, a proportion of central cells in squamoid clusters stained with antibody to MBCK, and myoepithelial cells were unstained. By 8 days after arterial ligation, cell clusters exhibiting squamous metaplasia were completely unstained with antibody to MBCK, despite the presence ultrastructurally of numerous tonofilament bundles in both types of cells forming these clusters. The propensity for squamous alteration of acinar-intercalated duct complexes has important connotations for salivary gland tumors such as pleomorphic adenoma and mucoepidermoid carcinoma.     

Inverted ductal papilloma of minor salivary gland: case report with immunohistochemical study and literature review

Inverted ductal papilloma (IDP) is a type of ductal papilloma arising in ducts of minor salivary glands. Very few cases, and no cases in Japan, have been reported. Reported herein is a case of IDP with a review of the literature. The patient was a 49-year-old man presenting with a lump in the right buccal mucosa of the premolar area of the mandible. The tumor was excised en bloc after a biopsy diagnosis of IDP. On the surface of the covering epithelium, an opening was seen to be filled with mucinous material. On cut surface the opening led to the tumor cavity. The major portion of the tumor parenchyma was made up of papillary proliferation of basaloid squamous cells. Some crypts, microcysts, and mucous cells were seen. There were no findings suggestive of a malignant tumor. The patient's postoperative course was uneventful and there has been no recurrence after 1 year's follow up. Immunohistochemical analysis of the present case supports the hypothesis that IDP originates from squamous metaplasia and proliferation of minor salivary gland duct cells.     

Hemangioma of the salivary gland: a study of ten cases of a rarely biopsied/excised lesion

Hemangioma is a common soft tissue tumor that frequently occurs in the oral and maxillofacial region including salivary glands, but is rarely biopsied and is therefore often unfamiliar to the surgical pathologist. Our study examined the subclassification and histologic features of salivary gland hemangioma (SGH). Consultative cases coded as hemangioma and located in salivary gland from 1970 to 2000 were retrieved from the Registry of Oral and Maxillofacial Pathology of the Armed Forces Institute of Pathology (Washington, DC). Only cases with histologic evidence of salivary gland involvement were included. Slide material and patient history for all cases were reviewed, subclassification assigned, and histologic features were noted. Ten cases coded as hemangioma with slides and history met our inclusion criteria. Seven cases were the "juvenile hemangioma" subtype in the parotid of infants, ranging in age from 3 to 10 months (mean age, 5.3 months) with a male predominance. These SGH had a distinctive histologic appearance of a cellular proliferation of capillary sized vessels around retained salivary gland ducts. Mitoses were easily identified. Three additional cases in females included an arteriovenous hemangioma of a lip minor salivary gland since birth in a 15-month-old infant and two parotid gland lesions: a lobular capillary hemangioma of a 10-year-old and a cavernous hemangioma in a 51-year-old. The latter three cases grew as replacing masses and lacked retained salivary gland ducts within the lesion, despite glandular tissue at the periphery of the tumor. No SGH cases in our series were identified in the submandibular or sublingual glands. Despite its common occurrence, SGH is relatively rare in our surgical pathology files. The parotid gland is the most common location (90%). Salivary gland hemangioma includes usual hemangioma subtypes, mainly in females, and a distinctive infantile subtype of capillary hemangioma (juvenile hemangioma), displaying distinctive histology and found predominately in males. The cellularity, mitotic activity, and retained salivary gland ducts in the latter lesion should not make one consider malignancy.     

Juvenile sclerosing polycystic adenosis cytologically mimicking Warthin tumor

Sclerosing polycystic adenosis (SPA) is a rare salivary gland disease. Histologically it resembles a low‐grade ductal carcinoma in situ or sclerosing adenosis of the breast, characterized by lobular proliferation of ducts with apocrine cellular features surrounded by fibrosclerotic stroma. Although SPA is typically benign, recurrence is not uncommon, and cases with a malignant component have been documented. Thus, complete excision is desirable but preoperative diagnosis is challenging. A 12‐year‐old boy presented with a painless mass in the right neck. We identified a well‐demarcated mass in the right parotid region measuring approximately 2 cm using cervical echography and magnetic resonance (MR) imaging. Fine‐needle aspiration (FNA) revealed two cell types. There were loosely cohesive clusters of polymorphic epithelioid cells with irregular nuclei and abundant vacuolated cytoplasm containing zymogen granules. Some of these cells were binuclear. The other cell types represented normal ductal cells. The original cytological diagnosis was Warthin tumor. Right parotidectomy was performed. Histologically, we observed proliferation of ducts with granular, vacuolated, zymogen granules, and apocrine‐like features in the cytoplasm with hyalinizing sclerotic stroma and some binuclear cells. Four years after parotidectomy, there has been no recurrence or malignant transformation.Cytological diagnosis of SPA is challenging on FNA specimens since SPA is a very rare entity of the salivary gland that can mimic other salivary gland neoplasms. A mixture of apocrine‐like cells and sebaceous‐like cells, nuclear pleomorphism, and zymogen granules can help to diagnose this rare lesion during the initial cytological diagnosis.     

Metaplastic Breast Carcinoma Invading Chest Wall

Metaplastic breast carcinoma refers to a heterogeneous group of neoplasms in which the typical glandular growth pattern of the tumor undergoes metaplasia, either epithelial or stromal. A 59-year-old woman presented with a breast mass that recurred in 1 year and showed invasion of the chest wall. Histological sections of both the tumor and the recurrence showed a tumor composed predominantly of stromal spindle cells with neoplastic epithelial ducts. Squamous metaplasia was seen in some ducts. Immunohistochemical staining showed positive cytokeratin and epithelial membrane antigen staining of the epithelial cells. Smooth muscle actin, S100, and vimentin were diffusely positive in the stromal cells. Electron microscopy of the original lesion showed cells with squamous epithelial and smooth muscle characteristics, and other cells that formed lumens into which microvilli projected. Electron microscopy of the recurrent lesion showed primarily spindle-shaped cells with abundant tonofilaments in the perinuclear cytoplasm, desmosomes with associated tonofilaments, filaments with focal densities, often aligned parallel with the cell membranes, surface attachment plaques, and fragments of basement membrane. Pinocytotic vesicles were rare. These metaplastic cells are derived from myoepithelial cells which are multipotential and able to differentiate into epithelial or stromal cells.     

Salivary gland monomorphic adenoma. Ultrastructural,immunoperoxidase, and histogenetic aspects.

Monomorphic adenoma of basal cell type is a salivary gland tumor believed to result from a proliferation of a single type of cell. However, ultrastructural and immunocytochemical investigations of 6 monomorphic adenomas (5 from parotid and 1 from intraoral minor salivary gland) indicate that there are two classes of these lesions, one composed of two types of tumor cells and the other wholly or predominantly made up of one type of cell (isomorphic). In the former group, the organization of the tumor cells closely mimicked that of normal and hyperplastic salivary gland intercalated ducts. Aggregates of tumor cells were arranged as an inner layer of luminal epithelial cells which were surrounded by an outer layer of cells that, in some cases, had ultrastructural and immunohistochemical features indicating myoepithelial cell differentiation. In some adenomas formed by two types of tumor cells, basal-lamina-lined extracellular spaces were identified ultrastructurally in relation to modified myoepithelial cells; such spaces had the same fine-structural features as those reported in pleomorphic adenoma and adenoid cystic carcinoma. Predominantly isomorphic adenomas were composed exclusively of luminal epithelial cells. These results indicate that despite the varied histologic patterns in the numerous subtypes of monomorphic adenoma, there is a central theme of differentiation and organization in this type of neoplasm which recapitulates the ductoacinar unit of normal salivary gland parenchyma.     

Basal cell adenocarcinoma of the palate with squamous metaplasia

Basal cell adenocarcinoma is a rare salivary gland tumour, especially in minor glands. The clinical, histological, and immunohistochemical features of a case involving the palate are described. Formalin fixed, paraffin embedded sections of the tumour were examined in haematoxylin and eosin (H&E) sections and also using immunostaining for cytokeratins 7, 8, 13, 14, 18, 19, vimentin, muscle specific actin (HHF35), and laminin. H&E sections showed that the tumour was composed mainly of basaloid cells and a striking feature was the presence of squamous metaplasia. Neural invasion was also conspicuous. Immunohistochemical reactions indicated that cytokeratin 14 was expressed by all tumour cells and vimentin by all cells except those in the areas of squamous metaplasia. The remaining cytokeratins and actin were present in some of the tumour cells, while laminin showed discreet positivity around cell arrangements. The foci of squamous metaplasia and the immunohistochemical findings are helpful in distinguishing basal cell adenocarcinoma from other salivary gland tumours which show basaloid cells.     

The congenital basal cell adenoma of salivary glands Contribution to the differential diagnosis of congenital salivary gland tumours

Congenital epithelial tumours of the salivary glands are very rare. The Salivary Gland Registry maintained in the Department of Pathology, University of Hamburg, contains only three cases among a total of 6,646 salivary gland tumours from the years 1965–1994. The three cases were classified as congenital basal cell adenoma, two of the parotid gland and one of the submandibular gland. Histologically, the three adenomas were similar in structure to the adult counterpart of basal cell adenoma with solid, trabecular or tubular (duct-like) patterns. In some cystic spaces of the duct-like structures PAS- and Astra blue-positive substances were secreted. On immunocytochemistry, the luminal duct-like cells showed membranous expression of cytokeratins 3, 5, 6, 7, 13 and 19. In the isomorphic basaloid cells of the solid and trabecular cell nests few cells expressed cytokeratin. On the outside of the solid cell nests there were smaller elongated myoepithelial-like cells, which expressed cytokeratin 14 and vimentin. Cytokeratins 1, 2, 4 and 18 were not expressed. The pattern of expression reflects the different stages of maturity of the tumour cells and is related to the development of the salivary glands until the end of the 3rd embryonal month with an arrest of further cell differentiation. No acinic cells, invasive growth, recurrence or metastases were observed. The differential diagnosis includes other congenital salivary gland tumours, such as hybrid basal cell adenoma-adenoid cystic carcinoma, sialoblastoma or embryoma, carcinoma, hamartoma and teratoma.     

Immunostaining patterns of myoepithelial cells in breast lesions: a comparison of CD10 and smooth muscle myosin heavy chain

BACKGROUND: Recent studies have reported CD10 expression in myoepithelial cells (MEC) of the breast, supporting its use as a marker to help distinguish invasive breast carcinoma (IC) from ductal carcinoma in situ (DCIS). Aim: To compare the effectiveness of CD10 with smooth muscle myosin heavy chain (SMMHC) in the detection of MEC in benign and malignant breast lesions. METHODS: Histological material from 25 patients with DCIS and 21 with IC were immunostained for CD10 and SMMHC. Staining was scored on a scale of 0 to 3+ (0, no staining; 3+, intense) and the staining distribution was documented as focal, partial, or circumferential. RESULTS: Uniform, 3+ circumferential CD10 and SMMHC staining of MEC was seen in normal breast ducts and lobules, and in ducts and acini involved in sclerosing adenosis and apocrine metaplasia. In an analysis of total ducts involved by DCIS, 3+ circumferential staining was seen in 65 of 366 ducts (17.7%) stained for CD10 versus 190 of 396 ducts (48%) stained for SMMHC. MEC were not detected immunohistochemically in 116 of 366 ducts (31.7%) with anti-CD10 and 50 of 396 (12.7%) with anti-SMMHC. In contrast, all ICs were negative for both CD10 and SMMHC. Focal background staining of stromal myofibroblasts was seen with both CD10 and SMMHC, but CD10 showed a higher rate of non-specific staining of epithelial cells. CONCLUSION: Although CD10 can aid in the distinction between IC and DCIS, SMMHC is a more sensitive and specific marker of MEC and shows less heterogeneity of immunostaining patterns.     

Kuttner's tumor of salivary glands resembling marginal zone B-cell lymphoma of the MALT type: a histopathologic and immunohistochemical study of 7 cases

Kuttner's tumor is a benign inflammatory process of the submandibular gland that presents as a hard mass mimicking a malignant neoplasm clinically. The histologic feature varies according to stage of evolution and severity of inflammation. We report here 7 cases of Kuttner's tumor that morphologically resemble primary salivary gland marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type. Histologically, the lobular architecture was distorted and the septa showed sclerosis. There was a dense lymphoplasmacytoid infiltration with lymphoid follicle formation accompanied by loss of acini and ducts. In 4 cases, a few salivary gland ducts contained the lymphoid cells within the epithelium. However, a true lymphoepithelial lesion was observed in none of the 7 cases. Immunohistochemical study demonstrated a disrupted follicular dendritic cell network, which is a characteristic finding of follicular colonization of MALT-type lymphoma. In 6 cases, there were a few small foci of lymphocytes somewhat resembling centrocyte-like cells of MALT-type lymphoma. However, immunohistological study demonstrated the mixed nature of the cells resembling centrocyte-like cells. Moreover, the polytypic nature of B lymphocytes was demonstrated by immunohistochemistry and polymerase chain reaction.     

Warthin's Tumor: An Ultrastructural and Immunohistochemical Study of Basilar Epithelium

The cellular characteristics of the basilar epithelium in Warthin's tumor have had limited investigation. Ultrastructural examination of basal cells in 9 Warthin's tumors reveals that in addition to numerous mitochondria these cells possess a rich complement of tonofilaments. However, in three examples there are a proportion of these tonofilament-rich cells that have a narrow band of microfilaments in the peripheral cytoplasm adjacent to the basal lamina. Frozen sections of Warthin's tumor and normal salivary glands, doubly labeled with rhodamine-phalloidin for actin and monoclonal antibody 312C8-1 for cytokeratin 14, show that normal myoepithelial cells of acini and intercalated ducts have both of these filaments, as do a proportion of basal cells in the tumor. There are distinct differences in the cytokeratin polypeptide complement between normal luminal and myoepithelial cells as well as between luminal and basal cells in Warthin's tumor. Differences occur in the cytokeratin profiles between the luminal and basal cells of Warthin's tumor and comparable cells in the normal gland; however, there continue to be some similarities in the cytokeratin polypeptides of myoepithelium and the basal cells of normal salivary ducts and the basal cells of Warthin's tumor. These findings show that basal cells in Warthin's tumor are a mixed population with some capable of differentiating as myoepithelial-like cells, and that this tumor could arise from any level of the normal salivary gland duct system.     

Warthin's Tumor: An Ultrastructural and Immunohistochemical Study of Basilar Epithelium

The cellular characteristics of the basilar epithelium in Warthin's tumor have had limited investigation. Ultrastructural examination of basal cells in 9 Warthin's tumors reveals that in addition to numerous mitochondria these cells possess a rich complement of tonofilaments. However, in three examples there are a proportion of these tonofilament-rich cells that have a narrow band of microfilaments in the peripheral cytoplasm adjacent to the basal lamina. Frozen sections of Warthin's tumor and normal salivary glands, doubly labeled with rhodamine-phalloidin for actin and monoclonal antibody 312C8-1 for cytokeratin 14, show that normal myoepithelial cells of acini and intercalated ducts have both of these filaments, as do a proportion of basal cells in the tumor. There are distinct differences in the cytokeratin polypeptide complement between normal luminal and myoepithelial cells as well as between luminal and basal cells in Warthin's tumor. Differences occur in the cytokeratin profiles between the luminal and basal cells of Warthin's tumor and comparable cells in the normal gland; however, there continue to be some similarities in the cytokeratin polypeptides of myoepithelium and the basal cells of normal salivary ducts and the basal cells of Warthin's tumor. These findings show that basal cells in Warthin's tumor are a mixed population with some capable of differentiating as myoepithelial-like cells, and that this tumor could arise from any level of the normal salivary gland duct system.     

Salivary duct carcinoma in situ of the parotid gland

Aims: To describe three cases of purely in situ salivary duct carcinoma, so as better to define the entity. Methods and results: Three primary tumours of the parotid gland are presented, in each case composed of cysts and ducts and lined by high nuclear grade epithelial cells. All parts of each tumour were surrounded by a myoepithelial cell rim and there was no evidence of invasion. The tumour cells expressed immunohistochemical markers seen in invasive salivary duct carcinoma of usual (high‐grade) type. In two cases the androgen receptor (AR) reaction was strong, but there was no immunohistochemical expression of HER2 protein or gene amplification by in situ hybridization. In the remaining case, fewer nuclei stained for AR, but both HER2 protein and gene amplification were demonstrated. Conclusions: Salivary duct carcinoma in situ is morphologically similar to breast ductal carcinoma in situ and, although our cases are few, salivary duct carcinoma in situ can possibly be subdivided into luminal and non‐luminal cell types, as can analogous mammary neoplasms. The present study cannot determine whether low‐grade cribriform cystadenocarcinoma, architecturally similar but immunohistochemically different, is part of the spectrum of salivary duct carcinoma in situ, or whether it represents a separate entity.     

The relation between anti‐TGBFR1 immunohistochemical reaction and low Ki67, small tumor size and high estrogen receptor expression in invasive breast cancer

Most breast cancers are derived from the luminal epithelium, which composes the inside of the breast ductal structure. Ductal carcinoma in situ (DCIS) leads to invasive ductal carcinoma, but noncancerous intraductal proliferative lesions are also a risk factor for ductal carcinoma. The transforming growth factor beta (TGFB) signaling pathway behaves as a tumor suppressor in the early stage of cancer, and conversely as a tumor growth factor in invasive stages in several cancers. In this study, we performed immunohistochemistry with an antibody that detects the cytoplasmic region of TGFB receptor 1 (TGFBR1) and elucidated TGFBR1 protein expression in luminal epithelial cells of noncancerous breast ducts and in several cases of DCIS and invasive carcinoma. TGFBR1 expression was higher in noncancerous breast tissue than in cancerous tissue, and a difference in expression was also seen among histological subtypes. Comparing the expression level of TGFBR1 in cancer cells and clinico‐pathological parameters, cases expressing low TGFBR1 tended to show low estrogen receptor expression, large tumor size (≥10 mm), and a high Ki67 labeling index. These data suggested that TGFBR1 protein expression may be related to the suppression of breast cancer cell growth.     

Salivary duct carcinoma in five cats.

Carcinomas of salivary gland ducts are described in five cats. The typical histological pattern was the formation of large cell aggregates resembling dilated ducts, often with central necrosis and a looping pattern. All tumours were labelled with antibody to cytokeratins (CKs) 5, 6, 8, 14, 17 and 19. Labelling of tumour cells with CK14 suggested basal cell differentiation. All tumours stained with Jack bean (Canavalia ensiformis) agglutinin (Con A); this is a feature of normal salivary gland ducts but is seen in other salivary gland tumours. Staining of tumour cells at the luminal surface of ductal structures with wheat germ (Triticum vulgaris) agglutinin (WGA) in the cat tumours was similar to that seen in ducts of normal cat salivary glands but occurs in other cat tumours. Other immunohistochemical staining results were unremarkable. 1999 Harcourt Publishers Ltd.     

Association of hepatocyte growth factor expression with salivary gland tumor differentiation

To clarify the significance of hepatocyte growth factor (HGF) expression in salivary gland tumors, HGF distribution in tissue sections and HGF concentrations in saliva and serum were examined. Sixty salivary gland adenomas, 61 salivary gland carcinomas and three autopsy fetuses were studied. Hepatocyte growth factor expression was observed in the duct-type luminal cells by immunohistochemical staining and in situ hybridization. However, HGF failed to be expressed in acinar cells and myoepithelium of normal salivary gland tissue. Hepatocyte growth factor tended to be expressed more intensely in benign salivary gland tumors than in malignant salivary gland tumors (P < 0.0001). In highly malignant tumors, the expression was limited in some cases. Salivary and serological HGF concentrations of 18 patients, comprised of 12 benign cases and six malignant cases, were analyzed before and after operation by an ELISA system. The concentrations were distinctly elevated after operation, in both saliva and serum, compared to before operation (P < 0.0005). However, there were no significant relationships between HGF concentration and histology, age, gender, size or location. Our findings suggest that HGF may play an important role in the development of salivary ducts of normal salivary tissues and differentiation of ductal structures of their neoplasms, while HGF kinetics in saliva and serum would be less likely to reflect the neoplastic character, benign or malignant.     

Kimura disease with proliferative squamous metaplasia: an unusual finding and a potential diagnostic pitfall

Kimura disease is a rare form of chronic inflammatory disorder involving subcutaneous tissue, predominantly in the head and neck region and frequently associated with regional lymphadenopathy and/or salivary gland involvement. We present a case of Kimura disease in a 28-year-old male which showed florid squamous metaplasia in the salivary gland ducts and salivary duct inclusions in the intraparotid nodes besides the usual features of Kimura disease. The squamous metaplasia was extensive enough to pose a diagnostic dilemma. We describe this case to highlight the rare histological finding of florid squamous metaplasia in Kimura disease and its diagnostic implications.     

Cylindroma (dermal analog tumor) of the breast: a comparison with cylindroma of the skin and adenoid cystic carcinoma of the breast

We compared 4 breast cylindromas with 50 dermal cylindromas and 8 adenoid cystic breast carcinomas. Except for a modest increase in the number of eccrine ducts and reactive Langerhans cells in dermal cylindromas, breast and dermal cylindromas showed identical histologic and immunohistochemical features. Both were characterized by epithelial islands containing central basaloid cells and peripheral myoepithelial cells surrounded by a thickened, continuous, periodic acid-Schiff-positive basement membrane that was immunoreactive for collagen IV. Clusters of sebaceous cells and a few eccrine ducts are described in breast cylindromas. Cytokeratin 7 labeled predominantly the central basaloid cells, and smooth muscle actin stained peripheral myoepithelial cells in breast and dermal cylindromas. Eccrine ducts were highlighted by epithelial membrane antigen and carcinoembryonic antigen. S-100 protein and CD1a showed a variable number of dendritic Langerhans cells. Cylindromas of the breast and skin did not express cytokeratin 20, gross cystic disease fluid protein 15, or estrogen or progesterone receptor. Breast cylindroma might be confused with the solid variant of adenoid cystic carcinoma, especially in needle core biopsy specimens, because they share nodular and trabecular patterns, basaloid cells, myoepithelial cells, eccrine ducts, and hyaline globules of basement membrane material. However, adenoid cystic carcinoma displays an infiltrative growth pattern, cytologic atypia, and mitotic figures and lacks the continuous, thickened basement membrane.