Primary Malignant Fibrous Histiocytoma of the Spleen-an Extremely Rare Entity

Undifferentiated pleomorphic sarcoma of the spleen: a case report and literature review

BACKGROUND

Undifferentiated pleomorphic sarcoma is an uncommon sarcoma and its presence in the spleen is even rarer, with only a handful of cases reported in English literature. It is typically only diagnosed following histological analysis. Its rarity also means that there is little consensus over ideal management.

CASE PRESENTATION

This report presents a case of a 40-year-old Caucasian male who was found to have a splenic mass after presenting with non-specific abdominal pain and generalized malaise. Numerous imaging modalities were used which demonstrated a large partially solid and partially cystic lesion in spleen with no evidence of metastasis. As core biopsies were undiagnostic, he was planned for a diagnostic and therapeutic splenectomy. However, despite magnetic resonance imaging 11 days prior to his operation showed no evidence of liver metastasis, a massive splenic tumour with hepatic metastases was identified intraoperatively. An open splenectomy, distal pancreatectomy and liver metastasectomy was hence carried out. Histological analysis confirmed liver metastasis secondary to a splenic undifferentiated pleomorphic sarcoma. The patient recovered well and was discharged home. He presented again three weeks after his operation with lower back pain, abdominal pain and fever. Computed tomography demonstrated extensive recurrent disease burden in the peritoneum and liver. The patient passed away a month after surgery.

CONCLUSION

Splenic undifferentiated pleomorphic sarcoma is a rare tumour which may pose a significant diagnostic challenge on both clinical and histopathological grounds. Following diagnosis and treatment, its aggressive nature often results in a poor prognosis. Current literature fails to delineate any superior management strategy to increase survival.

Pleomorphic spindle cell sarcoma (PSCS) (formerly known as malignant fibrous histiocytoma, MFH) of the spleen, mimics an atypical haemangioma on 99mTc-RBC, CT and Ultrasound: staging with 18F-FDG PET/CT

A 63-year-old male was found to have a 7.5-cm splenic mass that had imaging appearances of an atypical haemangioma on CT, ultrasound and a ^99mTc-RBC scan, and he was followed conservatively with serial ultrasounds. Sixteen months later, however, the splenic lesion grew and he developed numerous new liver masses which were biopsy confirmed to be a pleomorphic spindle cell sarcoma (PSCS), formerly known as malignant fibrous histiocytoma (MFH). A staging ¹⁸F-FDG PET/CT was performed and showed innumerable, mostly necrotic hepatic and splenic masses. The patient passed away a few days after the PET/CT, before a treatment program could be implemented. The use of ¹⁸F-FDG PET/CT in the staging of splenic PSCS has not been previously described. We present the ^99mTc-RBC and ¹⁸F-FDG PET/CT image characteristics of a patient with splenic PSCS.