Hepatic Involvement of Histiocytic Sarcoma: CT and MRI Findings

Primary carcinosarcoma of the liver: imaging features and clinical findings in six cases and a review of the literature

Background

Carcinosarcoma of the liver is a very rare tumor composed of a mixture of carcinomatous and sarcomatous elements. Less than 25 adequately documented cases have been reported, with inadequate description of imaging features. In order to improve the awareness of this rare tumor, this study aimed to analyze the clinicopathologic and imaging features of six cases of hepatic carcinosarcoma (HCS) confirmed by surgical pathologic evaluation.

Methods

We retrospectively studied the clinicopathologic and imaging features of six cases of HCS (matching the World Health Organization definition) and discussed the differential diagnosis on the basis of imaging findings. The patients, including five men and one woman, were 38 to 69 years of age. Five patients underwent CT scans, one underwent MRI scans.

Results

While 3 patients were positive for hepatitis-B surface antigen, 2 had cirrhosis. The largest tumor diameter ranged from 5.0 to 21.0 cm. Satellite nodules, venous thrombi, and organ invasion (gastric wall, gallbladder, and right adrenal gland) were identified. Pathologically, the carcinomatous components corresponded to hepatocellular carcinoma in three cases, cholangiocellular carcinoma in one case, and adenocarcinoma in two cases. The sarcomatous components exhibited complex features, with undifferentiated spindle cells in five cases and a leiomyosarcoma in one. All tumors showed heterogeneous density/intensity with extensive cystic change and necrosis; spot calcification was observed in one case. Capsule was not identified. While four tumors showed heterogeneous hypervascular enhancement, two showed hypovascular enhancement. All patients underwent surgical resection. The follow-up period ranged from 2 to 18 months. Four patients died from recurrence and metastasis.

Conclusions

The clinical and imaging features of HCS are heterogeneous. Due to the heterogenous nature and very low morbidity of HCS, combination of careful analysis of imaging findings and clinical features might be useful for a more accurate diagnosis of HCS.

Histiocytic sarcoma with bladder involvement: Case report and literature review

We report an unusual case of histiocytic sarcoma with bladder involvement. An 80 year-old man with a previous history of diffuse large B-cell malignant lymphoma presented with hematuria and back pain. Serial urine cytologies revealed no urothelial malignant cells, but cystoscopy showed a large intravesical mass. The patient underwent transurethral resection (TUR) of the tumor. The bladder TUR specimen showed a widely infiltrating epithelioid neoplasm, with intense immunohistochemical positivity for CD45 and histiocytic markers (CD68, lysozime and fascin). Histopathological diagnosis was histiocytic sarcoma. As the patient's condition was progressively deteriorating, only palliative care was indicated and he died one month after TUR. Although histiocytic sarcoma can often be widespread at the time of diagnosis, to our knowledge, this is the first report of a case presenting with urinary symptoms. Histiocytic sarcoma can mimic many other malignant lesions, and only immunohistochemistry can define the tumor cells, allowing correct therapy. We discuss the differential diagnosis and possible associations.