February 2022 Medical Image of the Month: Multifocal Micronodular Pneumocyte Hyperplasia in the Setting of Tuberous Sclerosis

No abstract available. Article truncated at 150 words. A 22-year-old man with a known diagnosis of Tuberous Sclerosis Complex (TSC) presents for a follow-up unenhanced chest CT to re-evaluate pulmonary nodules seen in the lung bases on a prior abdominal CT. The patient also has a history of multiple renal lesions consistent with lipid-poor angiomyolipomas based on previous abdominal MRI findings. The chest CT demonstrated multiple scattered, randomly distributed sub-centimeter pulmonary nodules of solid or subsolid morphology [Figure 1A]. Those nodules visible in the lung bases on the prior abdominal CT had remined stable over the 12-month interval consistent with multifocal microscopic pneumocyte hyperplasia (MMPH)[Figure 1B,C]. Myocardial fatty foci (MFF) were visualized in the heart on soft tissue window display settings [Figure 2A] as were multiple scattered sclerotic bone lesions on bone window display settings [Figure 2B,C]. No pulmonary cysts were seen to suggest lymphangioleiomyomatosis (LAM) and there were no thoracic lymphangiomas. MMPH represents a benign hamartomatous proliferation …