Fine needle aspiration (FNA) cytology of pilomatrixoma

FNA smears from five histologically confirmed cases of pilomatrixoma were reviewed to delineate the cytological features helpful in diagnosis. A combination of basaloid cells, ghost cells and foreign body giant cells appeared to be necessary in FNA smear for a confident cytodiagnosis of pilomatrixoma. Presence of naked nuclei, nucleated squamous cells and calcification were additional features in favour of the diagnosis. Another 10 cases with initial cytodiagnosis of pilomatrixoma or benign skin appendage tumour were reviewed. Using the above criteria, diagnosis of pilomatrixoma was easy in five cases. One case was problematical due to presence of atypical squamous cells. Initially the cytological features were most commonly confused with epidermal inclusion cyst, giant cell lesion or a squamous cell carcinoma. The main reasons for erroneous diagnosis were lack of awareness of cytological features, predominance of one component over the others, and non‐representative FNA smears. Atypia in nucleated squamous cells, and misinterpretation of basaloid cells as malignant can lead to diagnostic dilemma. Adequate clinical data are also necessary.     

Fine needle aspiration cytologic findings in metastatic basaloid squamous cell carcinoma of the head and neck.

Basaloid squamous cell carcinoma of the head and neck is a variant of squamous carcinoma the cytomorphology of which has not been examined previously. The cytologic features of metastatic basaloid squamous cell carcinoma in fine needle aspiration specimens from nine patients are described. The primary tumors, when known, were located in the base of the tongue, tonsil, epiglottis, nasopharynx, hypopharynx and false vocal cord. Each neoplasm had large fragments or clusters of crowded cells and scattered single cells in the cytologic smears. The cells had round or oval, hyperchromatic nuclei that often had single, small nucleoli. The nuclei usually were small or medium sized, but six tumors had a few cells the nuclei of which were large and pleomorphic. The cytoplasm was typically scant, and only three cases had occasional keratinized cells. Necrosis was present in six neoplasms. Three neoplasms, originally diagnosed as small cell undifferentiated carcinoma, contained numerous single cells and small clusters of cells with nuclear molding. On review, however, smears from these neoplasms also contained a few large fragments of tightly cohesive cells with larger, vesicular nuclei. Another basaloid squamous cell carcinoma had been interpreted elsewhere as an adenoid cystic carcinoma because of the presence of pseudoglandular structures with stromal cores. Although the cytologic features of basaloid squamous cell carcinoma may mimic those of other poorly differentiated carcinomas in fine needle aspiration specimens, they are sufficiently distinctive that a diagnosis of this variant of squamous cell carcinoma can be suggested for a patient whose primary neoplasm is located in the upper aerodigestive tract.     

Thin-layer (liquid-based) cytologic findings of papillary squamotransitional cell carcinoma of the cervix. Review of cases over a 4-year period with emphasis on potential diagnostic pitfalls

OBJECTIVE: To describe the thin-layer cytology and diagnostic pitfalls of papillary squamotransitional cell carcinoma of the cervix, with clinical and histologic correlation. STUDY DESIGN: The author reviewed the clinical findings, thin-layer cytology and histologic features of papillary squamotransitional cell carcinoma of the cervix encountered at Pamela Youde Nethersole Eastern Hospital, Hong Kong, during the 4-year period January 1998-March 2002. Strict histologic criteria (basaloid/transitional cell-like cells constituted > 70% of the tumor cell population and papillary/anastomosing, frondlike structures seen in > 70% of tumor tissue in superficial biopsies) were employed in defining this entity. RESULTS: During the study period, 10 biopsy cases of carcinoma of the lower female genital tract (9 in cervix and 1 in vagina) fulfilled the above histologic criteria. Six of them had thin-layer cytology performed The preparations were often of moderate to high cellularity and contained three-dimensional, arborizing, papillary clusters of basal/parabasal cells. Discernible fibrovascular cores were sometimes identified. Occasionally at the papillary surface, the basaloid cells were aligned horizontally. High-power cytology of the tumor cells ranged from bland-looking to high grade squamous intraepithelial lesions (HSILs) and sometimes squamous cell carcinoma. Mitotic figures were commonly identified. Tumor diathesis and dyskeratotic cells were occasional. Koilocytosis was not observed. Subsequent tumor biopsies showed evidence of stromal invasion in 3 cases. CONCLUSION: Papillary squamotransitional cell carcinoma has a distinctive appearance in thin-layer cytologic preparations. The predominance of bland-looking basaloid cells or HSIL cells, together with scantiness of tumor diathesis and carcinoma cells, may lead to underdiagnosis. Recognition of the subtle cytologic features and clinical correlation are essential in arriving at a correct diagnosis.     

Immunohistochemical studies of S-100 protein alpha and beta subunits in adenoid cystic carcinoma of salivary glands

Immunohistochemical studies were performed to explore the distribution of S-100 protein and its alpha, beta subunits in 76 adenoid cystic carcinomas (ACC) of the salivary glands. Histopathologically. ACC was divided into cribriform, tubular, basaloid and trabecular types which could be mixed in the same tumor. S-100 protein was usually positive in tumor cells forming cribriform structures; foci of strongly positive tumor cells were also distributed in the luminal layer of tubular structures, and in areas transitional between cribriform and tubular patterns. S-100 alpha staining was confined to some tumor cells in cribriform areas, to luminal tumor cells in tubular structures and to few tumor cells in basaloid structures. S-100 beta reaction was usually localized to luminal surfaces in a fine granular pattern in tubular and microtubular structures in a distribution somewhat similar to that in the normal salivary gland. Great heterogeneity in the immunohistochemical distribution of S-100, S-100 alpha and S-100 beta proteins was found in the various histologic types of ACC and the pattern was different from that seen in pleomorphic adenomas. It is possible that the ACC tumor cells positive for S-100 protein may be closely related to true or modified myoepithelial cells.     

Cytology of basaloid squamous carcinoma of the bronchus. A case report

BACKGROUND: The cytologic appearance of basaloid squamous carcinoma (BSC) arising in the lower respiratory tract has not been described very well because of its rarity. This article describes a surgical case of bronchial BSC and provides the first documentation of the sputum and imprint cytologic features of the tumor. CASE: A 74-year-old man presented with hemoptysis. An abnormal intrabronchial mass was revealed by computed tomography and bronchoscopy. Preoperative cytology and biopsy showed that the mass was composed of small, round, atypical cells, but correct diagnosis was difficult. Under a tentative diagnosis of small round cell carcinoma, a right lobectomy was performed. The resected tumor was composed of small cells showing peripheral palisading and partial epidermoid differentiation. There was no glandular differentiation. Focal necrosis was also noted. Immunohistochemical markers for smooth muscle and neuroendocrine cells were negative. The tumor was eventually diagnosed as BSC or basaloid carcinoma (BC) with squamous differentiation. CONCLUSION: It is important to recognize this disease, especially when undetermined small round cell carcinoma is noted in cytologic specimens, in order to properly assess prognosis. Cytologic detection of nuclear palisading of the neoplastic cells, one of the hallmarks of the disease, may be difficult, however, careful examination to reveal neoplastic cells showing squamous differentiation appears helpful for diagnosis.     

Pilomatricoma mimicking small round cell tumor on fine needle aspiration cytology: a case report

BACKGROUND: Pilomatricoma, a benign skin adnexal tumor, frequently leads to false positive diagnosis cytologically. We report a rapidly growing nodular swelling misdiagnosed as round cell tumor cytologically and found to be pilomatricoma histopathologically. CASE: A 32-year-old man presented with a rapidly growing, mobile nodule on his left arm for 4 months with fixed, shiny overlying skin. Fine needle aspiration cytology (FNAC) sample was cellular, showing round to ovoid cells dispersed or in clusters with occasionally rosette-like appearance. Cells displayed round, granular nuclei, single to multiple small nucleoli, absent to scant cytoplasm, a moderate amount of granular cytoplasm and apoptotic and mitotic figures in places. Nuclear moldings were encountered occasionally. Cytologically the diagnosis of blue round cell tumor was made. Histopathologic examination showed islands of basaloid cells with scant cytoplasm and shadow cells and occasional giant cells. The diagnosis was pilomatricoma bistopathologically. Rapidly growing, early lesions of pilomatricoma are predominantly composed of basaloid cells and mostly devoid of other diagnostic clues, leading to a false impression of malignancy. To avoid misdiagnosis, all skin-based nodules should undergo extensive cytologic sampling from diferent sites. Pilomatricoma should be considered in diferential diagnosis when primitive-appearing cells are aspirated, especially in rapidly growing early lesions.     

Immunohistochemical studies of S-100 protein α and β subunits in adenoid cystic carcinoma of salivary glands

Immunohistochemical studies were performed to explore the distribution of S-100 protein and its α,β subunits in 76 adenoid cystic carcinomas (ACC) of the salivary glands. Histopathologically, ACC was divided into cribriform, tubular, basaloid and trabecular types which could be mixed in the same tumor. S-100 protein was usually positive in tumor cells forming cribriform structures; foci of strongly positive tumor cells were also distributed in the luminal layer of tubular structures, and in areas transitional between cribriform and tubular patterns. S-100 α staining was confined to some tumor cells in cribriform areas, to luminal tumor cells in tubular structures and to few tumor cells in basaloid structures. S-100β reaction was usually localized to luminal surfaces in a fine granular pattern in tubular and microtubular structures in a distribution somewhat similar to that in the normal salivary gland. Great heterogeneity in the immunohistochemical distribution of S-100, S-100 a and S-100β proteins was found in the various histologic types of ACC and the pattern was different from that seen in pleomorphic adenomas. It is possible that the ACC tumor cells positive for S-100 protein may be closely related to true or modified myoepithelial cells.     

Fine needle aspiration (FNA) cytology of pilomatrixoma: report of 14 cases and review of the literature

We describe 14 cases of pilomatrixoma which were diagnosed preoperatively on FNA cytology. In contrast to the literature, our series showed male preponderance and some of the tumours in unusual locations such as thigh and breast. In three patients the tumours were larger than 5 cm. The clinical diagnosis varied from tumour not otherwise defined to sarcoma. The cytologic presentation had features which allowed a correct diagnosis in all cases and included basaloid cells surrounded by delicate pink fibres, shadow cells, giant cells, naked nuclei and calcium deposits. It is concluded that the FNA cytology of pilomatrixoma is characteristic and will allow a conclusive diagnosis even in cases with an aberrant clinical presentation.     

Ameloblastic fibroma. Report of a case with fine needle aspiration cytologic findings.

A case of ameloblastic fibroma of the jaw in an 18-year-old patient is presented. Fine needle aspiration cytologic smears showed two different types of cellular elements: a glandlike epithelial component, arranged in bidimensional, well-outlined clusters of basaloid cells with palisading of the columnar cells at the borders of those clusters, and a mesenchymal component that consisted of loosely arranged fusiform cells. These cytologic features appear to be sufficiently characteristic to suggest a diagnosis of ameloblastic fibroma by fine needle aspiration.     

Differential cytoskeletal association of ErbB1 and ErbB2 during keratinocyte differentiation

ErbB1 and ErbB2 display differential subcellular localization in human skin and cultured keratinocytes. To determine whether ErbB1 and ErbB2 also differ in cytoskeletal binding properties, normal human keratinocytes grown under conditions favoring a basal or differentiated phenotype were repeatedly extracted in a non-ionic detergent buffer. In basaloid keratinocytes, cytoskeletal association of ErbB1 and ErbB2 was limited. ErbB1 ( approximately 5%) was tightly associated with the cytoskeleton, compared to <1% of ErbB2 (p=0.004). After EGF stimulation, activated ErbB1 and ERK associated with the cytoskeleton to a greater extent than did total ErbB1 and total ERK. Association of ErbB2 increased markedly in differentiated keratinocytes, whereas association of ErbB1 was similar in basaloid and differentiated cells. Cytoskeletal association of ErbB2 correlated with plasma membrane localization. These results suggest that ErbB1 and ErbB2 employ different mechanisms of plasma membrane targeting during keratinocyte differentiation, and that cytoskeletal association may facilitate the coupling of activated ErbB1 and ERK.     

Fine needle aspiration cytologic findings in four cases of pilomatrixoma (calcifying epithelioma of Malherbe).

Four cases of pilomatrixoma studied by fine needle aspiration (FNA) biopsy prior to resection and histologic diagnosis were reviewed to identify the cytologic features useful in making the FNA cytodiagnosis. Cytopathology had initially correctly diagnosed two cases while misdiagnosing one as a carcinoma and one as a suspected carcinoma. The aspirates from all cases contained either clustered or isolated basaloid cells, with variably sized nuclei and prominent nucleoli. "Ghost cells" were also present in most smears stained with the Giemsa stain and could thus be very helpful for making the FNA diagnosis of pilomatrixoma. The occurrence of either foreign-body giant cells or calcium deposits in the aspirates could also contribute to suggesting the correct diagnosis of pilomatrixoma in some cases.     

Proteomic analysis distinguishes basaloid carcinoma as a distinct subtype of nonsmall cell lung carcinoma

The histopathologic type of lung cancer is known to be correlated with tumor behavior and prognosis. However, this classification is subjective and no specific molecular markers have been identified. The aim of this study was to identify protein markers in different types of nonsmall cell lung cancers. Two-dimensional polyacrylamide gel electrophoresis analysis was performed with paired samples of three squamous cell carcinomas, three adenocarcinomas, four large cell carcinomas, and four basaloid carcinomas. We found that 25 proteins in 14 cases of lung cancer were differentially expressed compared to matched nontumorous lung tissues. Among these 25 proteins, 11 proteins were down-regulated and 14 were up-regulated in these four types of lung cancer. Alloalbumin venezia, selenium-binding protein 1, carbonic dehydratase, heat shock 20KD-like protein, and SM22 alpha protein were down-regulated in all 14 cases of lung cancer examined, whereas alpha enolase was consistently up-regulated. Supervised hierarchical cluster analysis based on the 25 differentially expressed proteins showed that basaloid carcinoma formed one independent group, whereas the other three cancer types were not uniquely classifiable. Our findings suggest that basaloid carcinoma is a unique subtype of nonsmall cell lung carcinoma.     

Cytodiagnosis of simple and proliferating trichilemmal cysts

OBJECTIVE: To elucidate the cytologic findings in simple trichilemmal (pilar) cysts and proliferating trichilemmal cysts (pilar tumors) and the clinical importance of these lesions. STUDY DESIGN: Aspirates from 12 simple pilar cysts and three pilar tumors, all histologically confirmed, were analyzed with a view to elaborating on specific cytologic features enabling a distinction from epidermal cysts and other adnexal tumors. RESULTS: Aspirates from pilar cysts showed two different pictures, depending on the age of the cyst. Young pilar cysts showed aspirates with an abundant background of blotchy keratin with or without calcification and inflammation. Older (degenerating) cysts showed oily fluid debris with cholesterol crystals and inflammatory cells. The epithelial component was sparse, and only an occasional syncitial cluster of small squamoid cells was seen. As opposed to this, epidermal cysts usually showed a cleaner background, with very cellular aspirates containing many nucleate and anucleate squames, keratin flakes, platelike crystals and no calcification. The pilar tumors showed a lesser amount of keratin as compared to pilar cysts and yielded large and small clusters of squamoid and basaloid cells, a few of which showed an abrupt association with anucleate, keratinized globules. CONCLUSION: The cytologic diagnosis of a pilar cyst should be made especially in scalp cysts, which yield either abundant, blotchy keratin or oily, cholesterol-rich debris with a sparse epithelial component and which lack a mixture of anucleate and nucleate squames. On aspiration, pilar tumors yield comparatively more cells and less keratin and show small, basaloid or squamoid cells abruptly associated with keratin globules. The cytologic diagnosis of pilar cysts is important because these cysts recur if incompletely excised and often undergo transformation to pilar tumors. Similarly, pilar tumors often clinically mimic squamous carcinomas, and hence there is a need to outline definitive cytologic features.     

Fine needle aspiration cytology of malignant spiradenoma arising in congenital eccrine spiradenoma

The fine needle aspiration (FNA) cytology of malignant eccrine spiradenoma arising in a large benign congenital eccrine spiradenoma is described. The malignant tumor was characterized by cohesive, pleomorphic cells with malignant nuclear features and numerous mitoses. FNA of the adjacent benign eccrine spiradenoma revealed prominent basement membrane deposition with an irregular tubular and nesting growth pattern and bland basaloid cells. To our knowledge, the FNA of malignant eccrine spiradenoma has not been previously described. In this case, FNA cytology was influential in directing patient management.     

Cytology of recurrent ameloblastoma with malignant change. A case report

BACKGROUND: Ameloblastoma is a rare tumor of the jaw that arises from the odontogenic epithelium. Ameloblastomas have a propensity for local recurrence and, rarely, for metastasis. The term malignant ameloblastoma is reserved for those metastasizing tumors that retain the typical morphology of ameloblastoma. Fine needle aspiration (FNA) reports on ameloblastomas are scant, and those on malignant ameloblastomas are still more so. CASE: In a case of malignant ameloblastoma diagnosed by FNA cytology, the clinical presentation was that of a malignant neoplasm. FNA smears were highly cellular and showed isolated, scattered cells and small groups of basaloid cells and polygonal squamous epithelial cells. Stellate and spindle-shaped cells were also seen in the background. The cytologic diagnosis was subsequently confirmed on histopathology. CONCLUSION: The characteristic combination of cells in FNA smears facilitated the diagnosis of ameloblastoma. Since the biologic behavior of the tumor was that of a malignant neoplasm, the slides were reviewed. The cytologic smears did not exhibit sufficient features of malignancy to label the lesion malignant.     

Deep-seated rectal/anal basaloid carcinoma: useful immunocytochemistry in rare squamous cell carcinoma variants

Objectives:  To report the cytological aspects of ano-rectal basaloid carcinoma (BC) variant in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) conventional and liquid-based cytology (LBC), in a series of 10 cases of deep-seated squamous cell carcinomas (SCC), and to discuss the diagnostic difficulties in interpreting the morphology and immunocytochemical findings.
Methods:  Ten cases of EUS-FNA smears and LBC specimens of deep-seated pelvic masses were retrospectively collected from January 2001 to November 2006.
Results:  Ten EUS-FNA specimen cases were SCC, eight corresponding to usual SCC and two to BC-variant. Of these two cases, only one was correctly diagnosed by EUS-FNA specimen, whereas in the second case, the initial cytological diagnosis was poorly differentiated adenocarcinoma and the final diagnosis of basaloid carcinoma variant was established on surgical resection. Immunocytochemistry (ICC) using CK7, CK20 and CK34βe12 on FNA specimens confirmed the diagnosis retrospectively.
Conclusion:  The diagnosis of basaloid variant of SCC in a rectal location can be very difficult, both on account of the uncommon location and because of the low specificity of morphological aspects on EUS-FNA smears. The immunocytochemical technique, including a limited spectrum of keratins (CK7, CK20, CK34βe12, and p63) is necessary to avoid this diagnostic pitfall.     

Basal-cell adenoma of parotid. Difficulty of differentiation from adenoid cystic carcinoma on aspiration biopsy

Two cases of basal-cell adenoma (basaloid monomorphic adenoma, dermal analogue tumor) seen in a one-year period were subjected to fine needle aspiration biopsy and subsequent histologic confirmation. Two cases of adenoid cystic carcinoma occurring in the parotid region were selected for comparison; a great similarity between the two types of tumors was noted. On aspiration smear both lesions consisted of clusters and sheets of uniform, small, regular cells with scant basophilic cytoplasm and regular round or oval bland nuclei. The smears contained varying amounts of homogeneous, pale, eosinophilic stromal substance within and around the cell clusters. Individual cell differences between the two lesions were minimal, with the adenoid cystic carcinomas tending to exhibit more nuclear hyperchromatism and irregularity; the architectural arrangements of the cell clusters and the stromal substance permitted differentiation between the two lesions.