Primary hepatic leiomyosarcoma in a patient with autosomal dominant polycystic kidney disease.

Primary hepatic leiomyosarcoma is an extremely rare tumor. The diagnosis is difficult, and its etiologic factors have not been clarified. A 63-year-old woman with numerous cysts in her kidneys and liver was diagnosed with autosomal dominant polycystic kidney disease (ADPKD). Several members of her family also had ADPKD. She underwent treatment with tolvaptan to inhibit cyst growth and slow the decline in kidney function. Eight months after the start of the therapy, she was hospitalized with fatigue and fever of unknown origin. Diagnostic imaging showed a very large hepatic tumor, and histologic examination of a fine-needle biopsy specimen revealed the tumor to be malignant. Differentiation between carcinoma and sarcoma was difficult based on the histological findings. The tumor was thought to be excisable; therefore, hepatic resection was attempted. At the time of surgery, as the tumor had grown larger than when imaged, complete resection was impossible. However, a part of the tumor was resected. Histopathological and immunohistological examinations of the surgical specimen confirmed a primary hepatic leiomyosarcoma. Whether the tumor was associated with the presence of ADPKD remains unclear, however, this is the first report of the combination of these two diseases in a patient.