A 60-year-old man with a heavy smoking history presents with a persistent cough and a central lung lesion near the right hilum and hypercalcemia. Which diagnosis is most likely?

• A. Bronchioalveolar carcinoma
• B. Squamous cell carcinoma
• C. Adenocarcinoma
• D. Hamartoma

Answer: (B)

Central, hilar-located lung tumors in heavy smokers point to squamous cell carcinoma. This cancer tends to arise in the bronchial epithelium and often presents as a central mass near the hilum. A hallmark paraneoplastic feature is hypercalcemia, usually from tumor production of PTH-related peptide (PTHrP) that increases calcium release from bone and calcium reabsorption in the kidneys.

In contrast, adenocarcinoma is more likely peripheral and common in non-smokers; bronchioalveolar-type lesions are typically peripheral and have different imaging features, and hamartomas are benign lesions with characteristic calcifications and do not cause hypercalcemia. Thus, the combination of a central, hilar location and hypercalcemia best fits squamous cell carcinoma.