From the archives of MD Anderson Cancer Center: Small lymphocytic lymphoma/chronic lymphocytic leukemia diagnosed in Warthin tumor.

Warthin tumor is uncommonly associated with lymphoma. We describe a case of a 73-year-old man with persistent left neck swelling in the submandibular region. Core needle biopsy with aspiration showed Warthin tumor and small lymphocytic lymphoma (SLL)/chronic lymphocytic leukemia (CLL). Histologic sections showed fragments of a Warthin tumor composed of oncocytic ductal epithelium in a background of a diffuse infiltration of small lymphocytes with small proliferation centers. The lymphocytes were predominantly CD5-positive monotypic B-cells by immunophenotypic analysis. This is the first report in the literature describing a concurrent Warthin tumor and SLL/CLL diagnosed by needle biopsy with aspiration. Based on our review of the literature and including the current case, 45 cases of lymphoma involving Warthin tumor have been reported previously. Forty-four of these lymphomas were lymph node-based neoplasms, with follicular lymphoma most common (n = 15; 34 %). Five (11 %) cases of SLL/CLL associated with Warthin tumor including the current case have been reported. Notably, extranodal marginal zone lymphoma is rarely associated with Warthin tumor, reported in a single case. These findings support the hypothesis that Warthin tumor arises from heterotopic salivary gland ducts within lymph nodes. We review the pathogenesis of this uncommon phenomenon and discuss the differential diagnosis.