Cutaneous Carcinosarcoma With Myoepithelial Differentiation: Immunohistochemical and Cytogenetic Analysis of a Case Presenting in an Unusual Location

Abstract

Primary cutaneous carcinosarcoma is an uncommon tumor that is characterized by an admixture of malignant epithelial and mesenchymal elements. To our knowledge, only approximately forty cases have been reported to date in the literature. The majority of these neoplasms occurred on the extremities and the head and neck region of older individuals. We report an additional case, which presented in an 87-year-old man in an unusual location, the buttock. Histologically, the lesion was characterized by a biphasic proliferation of malignant epithelial areas admixed with an infiltrative, poorly differentiated spindle cell component. The epithelial areas consisted of nodular aggregates of basaloid to squamoid cells forming focal ductal structures with central lumens containing proteinaceous debris. The sarcomatoid component consisted of malignant spindle to epithelioid-appearing cells admixed with bizarre-appearing tumor giant cells within a myxochondroid stroma. The epithelial cells showed positive staining with pan-cytokeratin, BerEP4, p63, and keratin 5/6 and were focally positive for S-100, calponin, and actin, consistent with myoepithelial differentiation. An epithelial membrane antigen stain highlighted the scattered ductal structures. The high-grade spindle cell areas were negative for S-100, actin, desmin, calponin, p63, epithelial membrane antigen, and keratin 5/6.

Cutaneous basal cell carcinosarcoma: case report and literature review

“…The immunophenotypic studies performed in the reported cases are summarized in Table . Immunophenotypically, the basaloid epithelial component marks as expected, with immunoreactivity for cytokeratins, p63, bcl‐2, Ber‐EP4, variable EMA, and negative for mesenchymal and melanocytic markers.…”

“…Our case also showed coexpression of p16 and p63. Although p63 expression has been frequently reported in non‐cutaneous and squamous carcinosarcomas, it has been reported negative in all previous reports of basal cell carcinosarcomas . The coexpression of these three markers in both components supports the notion that they have a common origin.…”

“…In the reported cases, the epithelial component has been predominantly squamous cell and BCCs, and less frequently adnexal and Merkel cell carcinomas . Including this case, 47 cases of basal cell carcinosarcomas have been reported …”

Erythematous and Ulcerated Plaque on the Left Temple

“…4 Histologically, the sarcomatous components of PCCS often are highly variable, with an absence of transitional areas within the epithelial component, which frequently resembles basal cell carcinoma and/ or SCC. [5][6][7] Primary cutaneous carcinosarcoma favors areas of chronic UV radiation exposure, particularly on the head and neck. Most tumors present with a slowly growing, polypoid, flesh-colored to erythematous nodule due to the infiltrative mesenchymal component.…”

Primary Cutaneous Carcinosarcomas

“…The priority of long-term immunosuppression must be discussed critically. 42 In summary, division can be made into epithelial components (most commonly, BCCs and/or SCCs) and adnexal CS (benign/malignant spiradenomas, proliferating trichilemmal cystic carcinomas, or porocarcinomas).…”