Primary pulmonary Hodgkin's lymphoma: a rare pitfall in transthoracic fine needle aspiration cytology.

Primary pulmonary Hodgkin's lymphoma (PPHL) is extremely rare. At an extranodal location such as the lung this lymphoma is likely to be confused with the more commonly occurring carcinomas at this site. We report the fine needle aspiration cytology (FNAC) findings of a PPHL in a 36-year-old male with a view to discuss the pitfalls and clues to the accurate cytologic diagnosis. This patient presented with a large, heterogeneously enhancing mass involving the anterior segment of right upper lobe without any evidence of nodal involvement. A CT-guided transthoracic FNAC of this mass revealed large connective tissue fragments with entrapped voluminous cells amidst a polymorphous population of eosinophils, polymorphs, and lymphocytes. The large cells showed abundant often stripped off cytoplasm, an irregular nucleus with nucleolus and were initially diagnosed as non-small cell carcinoma of the lung. In view of the locally advanced stage, patient received a carboplatin and gemcite-based chemotherapy with complete response but postchemotherapy patient refused local surgery. Two years later, the patient developed enlarged nodes which were diagnosed as Hodgkin's lymphoma, and a review of prior lung tumor confirmed the diagnosis of PPHL. Hence the rare diagnosis of PPHL should be kept in mind when a cytopathologist observes large cells embedded in collagenous tissue fragments with dominant cell dispersal amidst an inflammatory infiltrate in an aspirate from a primary lung tumor.