A 58-year-old man with a 40 pack-year smoking history presents with hemoptysis and weight loss. CXR shows a central hilar mass with cavitation. Biopsy shows keratin pearls and intercellular bridges. Which paraneoplastic syndrome is most strongly associated with this tumor type?
- A Syndrome of inappropriate ADH secretion (SIADH)
- B Ectopic ACTH production causing Cushing syndrome
- C PTHrP-mediated hypercalcemia ✓
- D Lambert-Eaton myasthenic syndrome
Correct answer: C. PTHrP-mediated hypercalcemia
Explanation
The biopsy showing keratin pearls and intercellular bridges confirms squamous cell carcinoma, which is centrally located and strongly associated with smoking. Squamous cell lung carcinoma classically causes PTHrP-mediated hypercalcemia as a paraneoplastic syndrome. SIADH, ectopic ACTH, and Lambert-Eaton syndrome are paraneoplastic manifestations of small cell lung carcinoma, not squamous 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.