Low-grade fibromyxoid sarcoma with heterotopic bone formation: case report and review of the literature

Introduction/Objective Low-grade fibromyxoid sarcoma (LGFMS) is an uncommon soft tissue malignancy with deceptively bland histologic appearance, and a tendency for late recurrence and metastasis. Cases with significant heterotopic ossification are rare. This presentation aims to characterize the features of LGFMSs showing heterotopic ossification reported in the literature, and further review the morphologic spectrum of this malignant neoplasm. Methods/Case Report We report the case of a 42-year-old male presenting with a 20-year history of a painless tumor in his left upper thigh. Computed tomography images showed coarse punctate peripheral calcifications, and the mass was resected. The tumor cells were immunohistochemically positive for MUC4, and positive for FUS (16p11.2) gene rearrangement by fluorescence in situ hybridization. Lamellar and woven bone with admixed adipose tissue was seen. Immunohistochemistry also showed focal weak to moderate staining for TLE-1. An English literature search using the terms “Evans tumor”, “low-grade fibromyxoid sarcoma”, “ossification”, “osseous metaplasia”, “bone metaplasia” and “bone formation” was performed. Nine cases were identified. The majority of subjects were males, with a mean age of 38 years (range of 12-61 years). The duration of symptoms before diagnosis ranged from a few months to 10 years. The tumor size ranged from 2.5 and to more than 12 cm. In a minority of subjects, calcifications were identified on imaging studies. Histologically, bone metaplasia was mainly seen at the periphery of the tumor. The majority of cases had a chromosomal translocation (FUS-CREB3L2 in 5 cases and EWSR1-CREB3L1 in one). Results (if a Case Study enter NA) NA Conclusion LGFMS is a tumor that can occur in a wide range of anatomical sites, and should be included in the differential diagnosis of any spindle cell neoplasm with hypocellular areas and bland cytology. Pathologists and clinicians should be aware of the rare possibility of heterotopic ossification in this tumor type, which can be radiologically detected as calcification and then confirmed histopathologically.

Giant hand osteolipoma: Case Report

Hand lipomas are rare in the hand, and they account for less than 1% of tumors. Osteolipoma is a rare variant of lipoma that is associated with bone metaplasia. It presents as a painless tumor that can cause symptoms when compressing adjacent structures. Magnetic resonance imaging (MRI) is the imaging study of choice. The treatment is surgical resection, with no recurrences being reported. We present the case of a patient with a giant subfascial hand osteolipoma, which, to the best of our knowledge has not yet been reported in the literature.

Osteolipoma of Parotid Gland: A Rare Presentation

Background Osteolipoma is an uncommon benign tumor containing mature adipose tissue with bone metaplasia foci. It is rarely observed in head and neck region as compared to the lipoma, especially in the region of parotid gland. Case presentation: We report the first case of intraparotid osteolipoma with its clinical, radiographic and pathological findings. A 47-year-old men presented with an immovable mass in his left cheek with a 10-year evolution. Magnetic resonance imaging (MRI) scans showed a 3.2-cm fat-containing mass involving in the left parotid. The patient was taken to the operating room for excision of the mass and the final pathologic diagnosis was osteolipoma. Due to its rarity and clinical significance, we also reviewed the osteolipoma presenting in major salivary gland regions. Conclusion Intraparotid osteolipoma is an extremely rare neoplasm originating from adipogenic tissue, which should be taken into consideration in the differential diagnosis of parotid tumor.