Thoracic splenosis diagnosed by fine-needle aspiration cytology: a case report.

A case of thoracic splenosis diagnosed by fine-needle aspiration (FNA) of subpleural lung lesions is presented. The patient, a 49-yr-old male with a history of gunshot wound to his trunk with splenic rupture and splenectomy several years previously, presented with recent hemoptysis and multiple subpleural solid nodules shown in the left lung field by CT scan. As the possibility of a metastatic malignancy vs. mesothelioma was entertained, an FNA was performed on one of these lesions, revealing lymphoid tissue with abundant vascularity simulating the structure of splenic tissue. In view of this finding, supported by the absence of splenic outline in the CT radiograph, the diagnosis of splenosis was made. This is the fourth reported case of thoracic splenosis in which FNA cytology was utilized for diagnosis, yet the first in which the diagnosis was based exclusively on the FNA cytologic findings. Clinical, pathologic, and diagnostic aspects of this entity are discussed.