Sir, Malignant fibrous histocytoma (MFH) is the most common, malignant bone, and soft tissue tumor.[1] A 60-year-old male was admitted with a history of progressive distention of the abdomen since the last 6 months, that was not associated with pain, fever, loss of weight and appetite, or abdominal trauma. Abdominal examination revealed gross abdominal distention; the abdominal girth was 150 cm. There was a 60 × 60 cm2 intra-abdominal lump of variable consistency and an infraumbilical scar from a previous umbilical hernia repair procedure. On ultrasonography (USG) and computed tomography (CT) of the abdomen, a huge mass of mixed echogenicity and that gave inconclusive fine needle aspiration cytology (FNAC) results, was found to be separate from the liver, spleen, pancreas, kidneys, and the gut. Exploration revealed a huge mass having solid and cystic components occupying most of the abdominal cavity, separate from the liver superiorly and the gut inferiorly [Figure 1]. Inferiorly, the mass was adherent to the transverse colon, which was resected along with the mass and an end-to-end colocolic anastomosis was done. The whole resected tumor was 60 × 40 × 30 cm3 in size and weighed 32 kg. Cystic areas contained 1.5 l of dark brown fluid containing necrotic material. Histopathological examination revealed a fibrous histocytoma with mild pleomorphism, which was rare for such a large tumor. Postoperatively, the patient was given six cycles of chemotherapy consisting of Endoxan, Vincristine, Doxirubicin, and DTIC. CT of the abdomen showed no evidence of tumor recurrence after one year. Figure 1 The tumor during surgery Malignant fibrous histocytoma first described by O'Brien and Stout in 1964, is the most common soft tissue sarcoma occurring in the later stages of adult life.[2] The male-to-female ratio of its incidence is 2:1 and its incidence peaks in the fifth and sixth decades of life. The extremities (70-75% of the cases) followed by the retroperitoneum are the sites affected by this sarcoma.[3] Uncommon locations include the head and neck region, dura mater, brain, lung, aorta, pancreas, liver, spleen, breasts, intestine, and the mesentery.[4] The differential diagnosis of retroperitoneal MFH includes duplication cysts, pancreatic pseudocysts, cysticleiomyoma, leiomyosarcoma, teratoma, cysticmesotheliomas, lymphangioma, haematoma, abscess, and synovial sarcoma.[5] Retroperinoneal MFH should be considered in the differential diagnosis of abdominal cystic masses in older adults. Surgical excision is the first choice of treatment for MFH and its local recurrence. Due to its frequent metastasis, it is important to perform wide resection of the tumor including the connective tissue, fascia and muscles around the tumor, and the regional lymph nodes. Hashimoto[3] reported survival rates of >5 years in 87% of the cases treated with wide resection in comparison vs. only 50% of cases treated with simple excision. When the tumor becomes large without outward symptoms, curative resection becomes more difficult. Dalton et al.[6] reported survival rates >5 years in 56 and 36% of the patients with tumors larger than 5 cm in size and those with infiltrating tumors, respectively. It is assumed that cases with large tumors and with tumors of retroperitoneal origin have poor prognoses with frequent hematological metastases. Weiss and Enzinger[7] reported many advanced cases of MFH in whom the local recurrence and metastatic rates were 44 and 42%, respectively. According to Hashimoto,[3] metastasis has occurred in 61.5% of surgically treated patients within a year of surgery.
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Aug 5, 2024
Shivali Kashikar + 4
Open Access
