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.