Pulmonary non-Hodgkin's lymphoma (NHL) of diffuse large B-cell type with simultaneous humeral involvement in a young lady: An uncommon presentation with cytologic implications

A bronchogenic carcinoma, almost invariably, presents as a lung mass. Primary pulmonary lymphomas are rare. We report an unusual case of a pulmonary non‐Hodgkin's lymphoma (NHL) with simultaneous involvement of the right humerus in a 37 year old lady. Bronchial lavage smears showed atypical cells with irregular nuclear membranes raising a suspicion of a hematolymphoid tumor, over a small cell carcinoma that was the closest differential diagnosis. Biopsy from the lung mass and from the lesion in the humerus showed an identical malignant round cell tumor with prominent apoptosis. On immunohistochemistry (IHC), tumor cells were diffusely positive for leukocyte common antigen (LCA), CD20 and MIB1 (70%), while negative for cytokeratin (CK), epithelial membrane antigen (EMA) synaptophysin, chromogranin, neuron specific enolase (NSE), CD3, and CD10. Diagnosis of a pulmonary NHL of diffuse large B‐cell type with involvement of the humerus was formed. The case is presented to create an index of suspicion for the possibility of a NHL on respiratory samples, while dealing with small round cells with irregular nuclear membranes. IHC is necessary to confirm he diagnosis. A simultaneous association in the humerus in our case makes it unusual. Diagn. Cytopathol. 2010. © 2009 Wiley‐Liss, Inc.