Multifocal Micronodular Pneumocyte Hyperplasia and Osteosclerotic Lesions in a Patient with Tuberous Sclerosis Complex Misdiagnosed with Lung Adenocarcinoma.

A 45-year-old woman presented with multiple ground-glass nodules (GGNs) in both lungs. Osteosclerotic changes were observed on a thoracoabdominal computed tomography scan. She underwent surgical resection of a single GGN and was diagnosed with lung adenocarcinoma with bone metastases; however, neither lung nor bone lesions progressed. Pathological reexamination of the biopsy confirmed multifocal micronodular pneumocyte hyperplasia (MMPH) diagnosis, and subsequent genetic analysis identified a nonsense mutation in the tuberous sclerosis complex (TSC) 1 gene. The case report presented here suggests a potential role for MMPH and osteosclerotic lesions in diagnosing TSC.