A 65-year-old man with a 40 pack-year smoking history presents with hemoptysis. Bronchoscopy reveals a central, cavitating mass in the upper lobe. Biopsy shows keratin pearls and intercellular junctions. Which paraneoplastic syndrome is most classically associated with this tumor type?
- A Cushing syndrome
- B Myasthenia gravis
- C Hypercalcemia due to PTHrP secretion ✓
- D Polycythemia
Correct answer: C. Hypercalcemia due to PTHrP secretion
Explanation
The central cavitating upper lobe mass with keratin pearls and intercellular bridges (desmosomes) is classic squamous cell carcinoma of the lung. Squamous cell carcinoma classically causes humoral hypercalcemia of malignancy via PTHrP secretion. Cushing syndrome and SIADH are associated with small cell carcinoma. Myasthenia gravis is associated with thymoma. Polycythemia is associated with renal cell carcinoma.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.