Tuberous sclerosis diagnosed by incidental computed tomography findings of multifocal micronodular pneumocyte hyperplasia: a case report

INTRODUCTION: The majority of multifocal micronodular pneumocyte hyperplasia associated with tuberous sclerosis complex is diagnosed with the classical clinical triad of seizures, mental retardation, and skin lesions. We report a rare case of tuberous sclerosis complex with no classical clinical findings, which was diagnosed through incidental computed tomography findings of multiple nodular lesions of multifocal micronodular pneumocyte hyperplasia. CASE PRESENTATION: A chest computed tomography scan of a 51-year-old Japanese woman showed multiple nodular ground-glass opacities that were not seen on chest X-ray. Video-assisted thoracoscopic surgery was performed. A histological examination demonstrated type II pneumocyte hyperplasia with thickened fibrotic alveolar septa, which was consistent with multifocal micronodular pneumocyte hyperplasia. Brain magnetic resonance imaging displayed multiple cortical tubers, and abdominal computed tomography showed bilateral renal angiomyolipoma. Our patient was finally diagnosed as having tuberous sclerosis complex with multifocal micronodular pneumocyte hyperplasia, although she had no episodes of epilepsy, no skin lesions, and no family history. CONCLUSIONS: Multifocal micronodular pneumocyte hyperplasia with latent tuberous sclerosis complex should be considered in the differential diagnosis of multiple ground-glass opacities.