Role of positron emission tomography-computed tomography in bronchial mucoepidermoid carcinomas: a case series and review of the literature.

Introduction: Mucoepidermoid carcinoma of the tracheobronchial tree is rare. Such tumors usually present with signs and symptoms of bronchial obstruction. Histologically, they can be classified as high-grade or low-grade tumors. Experience of imaging these tumors with 18fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) is limited. We present three cases of this rare tumor, describe the functional imaging results, and review the available literature.

Case Presentation: Three Caucasian patients, two men (21 and 24 years of age) and one woman (14 years of age), with bronchial masses were evaluated by us. All three patients were symptomatic, and underwent a thorough clinical examination, bronchoscopy and biopsy, plain computed tomography, 18F-FDG PET-CT and 68Gallium 1,4,7,10-Tetraazacyclododecane-NI,NII,NIII,NIIII,- tetra acetic acid (D) - Phel1-Tyr3-octreotide positron emission tomography-computed tomography (68Ga-DOTATOC PET-CT). 18F-FDG PET-CT revealed mild uptake in all three patients, whereas 68Ga-DOTATOC PET-CT revealed no significant uptake in any patient, making carcinoid tumor unlikely. Results of histopathological examination were consistent with low-grade mucoepidermoid carcinoma in all patients.

Conclusion: Our study reveals that functional imaging may be helpful in the initial investigation of patients with mucoepidermoid carcinoma. 18F-FDG PET-CT may have a prognostic relevance by predicting the histopathologic differentiation of the tumor.