Synchronous metastatic cutaneous squamous cell carcinoma and chronic lymphocytic leukaemia/small lymphocytic lymphoma in a cervical lymph node: Case report of an unusual event.

UNLABELLED: The synchronous occurrence of two different neoplasias is an uncommon event, which may arise between tumors originating in the same organ or in cancer-to-cancer metastasis. We report a rare case of chronic lymphocytic leukaemia / small lymphocytic lymphoma associated with a cutaneous metastatic squamous cell carcinoma in a cervical lymph node. In the affected lymph node, it was observed an effacement of the normal architecture by neoplastic lymphocytes and it was noted the presence of neoplastic invasive epithelial islands. Immunohistochemical analysis demonstrated that lymphocytic proliferation was positive for CD20, CD5, CD23 and Kappa, and negative for CD3, CD10, Cyclin D1 and Lambda. The morphological and immunohistochemical profile lead to a phenotype of B-cell chronic lymphocytic leukaemia / small lymphocytic lymphoma. The epithelial cells were positive for CK5, thus rendering the diagnosis of synchronous metastatic cutaneous squamous cell carcinoma and chronic lymphocytic leukaemia/small lymphocytic lymphoma. Literature supports the poor prognosis in cases that present coexistence of squamous cell carcinoma and chronic lymphocytic leukaemia / small lymphocytic lymphoma. Thus, it is necessary to be aware about this unusual finding in order to provide specific treatment. KEY WORDS: Chronic lymphocytic leukaemia, small lymphocytic lymphoma, squamous cell carcinoma, metastasis.