Mucoepidermoid carcinoma of the lung: common findings and unusual appearances on CT.

Objectives: This study aimed to analyze the computed tomographic (CT) various findings of mucoepidermoid carcinoma of the lung and to improve the diagnostic efficacy for such tumor.

Materials And Methods: Sixteen consecutive patients with mucoepidermoid carcinoma of the lung confirmed by pathology were reviewed retrospectively. All the patients had undergone unenhanced and contrast-enhanced examinations; one of them also had undergone 18F-FDG PET/CT examinations.

Results: There were 6 males and 10 females with a mean age of 34.1 years. On CT plain scan, 14 out of 16 cases showed a well-defined endobronchus mass (n=12) or single peripheral nodule (n=2) with obstructive pneumonia or atelectasis (n=4), one case appeared a cavity in the tumor mass, and one presented diffuse circumferential wall thickening. Punctate calcification was observed in four cases (25%). Tumors showed mild (n=4, 25 %), moderate (n=6, 37.5%), and marked (n=6, 37.5%) degrees of contrast enhancement. Two patients had mediastinal lymph node metastasis, and one of them also had bone metastasis.

Conclusions: Mucoepidermoid carcinoma of the lung likely affects young adults. The common findings included a well-defined ovoid or rounded intraluminal mass; and uncommon findings included cavitation, diffuse thickening, or spiculation. Although CT manifestations of it are variable and nonspecific, a well-defined ovoid or lobulated intraluminal or lung peripheral mass with moderate to marked heterogeneous contrast enhancement may suggest the diagnosis of mucoepidermoid carcinoma of the lung. It should be included in the differential diagnosis of regional tumors.