Basaloid Squamous Cell Carcinoma of the Anus Revisited

Abstract

Basaloid squamous cell carcinoma (SCC) of the anus, previously called cloacogenic carcinoma, is a subtype of SCC. There are very few data on the morphologic variation within basaloid SCC of the anus, which may contribute to misdiagnosis. We retrospectively evaluated cases originally diagnosed as basaloid SCC for histologic characterization. We retrieved and reviewed cases of basaloid SCC from 1994 to 2013. Ten (27%) cases were reclassified after review, including basal cell carcinoma (n=6), melanoma (n=2), and neuroendocrine carcinoma (n=2). The final group of basaloid SCC (n=27) showed a female predominance (median age=60 y; range, 42 to 92 y). Morphologically, basaloid SCC could be categorized into 4 groups: transitional carcinoma like (n=10), basaloid with peripheral palisade (n=13), adenoid cystic carcinoma like (n=3), and mucinous microcystic (n=1). In 19 cases the histologic patterns were pure and were mixed in the remainder. CK5/6, p16, and high-risk HPV were positive in all cases (n=27). SOX2 was positive in 18/22 cases. Clinical follow-up was available on 60% of cases; 9 patients (53%) developed local recurrence or metastasis, and 5 (29%) died of disease. Basaloid SCC of the anus is characterized by 4 major histologic patterns and is consistently HPV driven.

A rare case of recurrent epidermoid anal cancer treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy—case report

“…In this case, the patient had not been operated on before, and there was no tumor extension to the peritoneal cavity, but there was advanced lymph node extension at initial presentation. Furthermore, the patient presented with basaloid SCC, a histologic subtype associated with increased risk of local and distant recurrence [26]. While it does not explain why the recurrence site was the…”

Successful treatment of basaloid squamous cell carcinoma in the rectosigmoid colon: A case report and review of literature

“…Distinguishing BSCC from other poorly differentiated carcinoma is difficult based on histopathological morphology because BSCC has several histological patterns such as mucoepidermoid and adenoid cystic carcinomas[ 3 , 15 , 16 ]. To improve histological differential diagnosis of BSCC, the most frequent morphologic pattern, including neoplastic cells arranged in trabeculae with a peripheral palisade, and focal squamous differentiation are useful.…”

“…To improve histological differential diagnosis of BSCC, the most frequent morphologic pattern, including neoplastic cells arranged in trabeculae with a peripheral palisade, and focal squamous differentiation are useful. Previous reports revealed that although the degree of squamous differentiation was variable, all cases had histopathological characteristics of basaloid carcinoma[ 3 , 17 ]. In our case, the histological criteria for BSCC, such as palisading pattern, elongated nuclei, and scant cytoplasm, were observed, and immunohistochemical staining was helpful for differential diagnosis.…”

“…Histopathological analysis is focused on its origin and differential diagnosis based on microscopic findings and immunohistochemical characterization. BSCCs are often misdiagnosed because they have several histological patterns such as mucoepidermoid carcinoma-like and adenoid cystic carcinoma-like patterns[ 3 ]. Immunohistochemistry can be performed for differential diagnosis of neuroendocrine tumors, gastrointestinal stromal tumor, and poorly differentiated anal and metastatic carcinomas from the lungs and genitourinary cancers[ 4 ].…”

Survival rate variation with different histological subtypes of poor prognostic male anal squamous cell carcinoma: a population-based study

“…Although the survival rate between genders varies significantly according to the histological subtypes, the confounding effect of other types of carcinomas was inevitable due to the restricted categorization. It was reported that about 30% of ASCC patients responded poor to chemoradiotherapy for unexplained reasons, and Graham et al [ 55 ] discovered 10 in 37 samples primitively classified as BSCC were misdiagnosed, including basal cell carcinoma (n=6), melanoma (n=2), and neuroendocrine carcinoma (n=2) and a female predominance was also noticed in the final BSCC group. A precise classification system is in need despite the fact that WHO recommends using the term “squamous carcinoma” to cover all pathological types of ASCC.…”