Chronic bronchitis mimicking metastases from thyroid medullary carcinoma demonstrated by indium-111 pentetreotide scintigraphy

We present a case of medullary thyroid carcinoma (MTC) with pulmonary symptoms, elevated calcitonin and CEA levels. Both [111In]pentetreotide (Octreoscan) scintigraphy and 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) scan revealed mild increased uptake of radionuclides in the upper lobe of the right lung compatible with metastases. Histopathological analysis showed it to be chronic bronchitis. The patient was followed without any treatment. Three months later, no pathological uptake on [111In]pentetreotide (Octreoscan) was observed. False positive [111In]pentetreotide uptake in the lungs was likely related to acute exacervation of the chronic bronchitis.