Pecoma of the lung: a benign tumor with extensive 18F-2-deoxy-D-glucose uptake.

A case of lung pecoma (i.e. tumors showing perivascular epithelioid cell differentiation) with extensive 18F-2-deoxy-D-glucose (FDG) uptake in PET/CT study is reported. Pecomas of the lung--which include the better known clear cell 'sugar' tumor--are a subset of extremely rare lung tumors which usually react positively to both melanocytic and smooth muscle markers. Although widely presumed as benign in computed tomography (CT) and positron emission tomography (PET)/CT studies they depict as malignant, thus complicating the preoperative diagnosis. A subset of pecomas could conceal a malignant potential.