MCQ – 88354

A 52-year-old woman presents with a 1-year history of upper truncal obesity and moderate depression. Physical examination shows hirsutism and moon facies. Endocrinologic studies reveal hypokalemia, high plasma corticotropin levels, and increased concentrations of serum and urine cortisol. CT scan of the thorax demonstrates a hilar mass. A transbronchial lung biopsy is shown in the image. Electron microscopy discloses neuroendocrine granules within the cytoplasm of some tumor cells. What is the appropriate diagnosis?

Correct Answer � D Explanation

Answer : D Small cell carcinoma

Small cell carcinoma (previously referred to as “oat-cell” carcinoma) is a highly malignant epithelial tumor of the lung that exhibits neuroendocrine features. 

It accounts for 20% of all lung cancers and is strongly associated with cigarette smoking.  Metastases occur early and are widespread. 

Carcinoid tumors  also contain neuroendocrine granules, but the tumor cells are arranged in a distinctive pattern.

Cushing syndrome is often encountered in patients with small cell carcinoma, but not carcinoid tumor.