A rare case report of a typical variant ossifying fibromyxoid tumor (OFMT), located in the retroauricular perimastoid region

Abstract

HighlightsOssifying fibromyxoid tumor of soft parts (OFMT) has an uncertain histopathogenesis and is characterized by a peripheral bone shell embedded in a fibromyxoid matrix.Folpe and Weiss proposed a classification with “typical”, “atypical” and “malignant” variants.The exam revealed a right perimastoid mass formation (2.2 × 1.2 × 2 cm) with an oval morphology, extended right to the back of the external ear canal, characterized by the predominant calcific component.The cytoplasm is described as a poorly eosinophilic, arranged to form solid nests and cords immersed in abundant collagenous and/or myxoid stroma, interposed in a mature irregularly shaped trabecular bone.Considering that it is extremely rare, and the possibility of local metastasis especially for the malignant type, we believe that more studies are required for this “enigmatic” tumor.

Ossifying fibromyxoid tumor of the soft tissue in the left upper arm and a review of the literature: A case report

“…When biopsy material is insufficient for pathological diagnosis, imaging techniques can be helpful, while it is more realistic to evaluate the nature of the tumors than determine their names. OFMTs commonly show positive staining for S-100 and vimentin (1,8), as in the present case. However, not all OFMT cases are positive for S-100 (16,20,21,41), potentially due to the enhanced histological malignancy (21).…”

“…Additionally, Min et al (18) described electron microscopic findings from three OFMT cases, such as centrally located round to oval nuclei, varying amounts of cytoplasm, few cytoplasmic organelles and absence of tonofilaments or actin filaments. Other studies also detected few mitotic cells in OFMT samples, particularly <1/10 HPF (22,23), while the Ki67 index is generally low (~1%) (8,22). Currently, there are no clear and accepted criteria for diagnosis of malignant subtypes of OFMT.…”

“…The most common site of OFMT is the thigh, while its incidence in the lower extremity is estimated to be >40% (1). Head and neck and trunk are also considered as tumor-prone sites (1)(2)(3)(4)(5)(6)(7)(8). The majority of tumors are subcutaneous, with only a few being intramuscular.…”

Ossifying fibromyxoid tumor: a rare case

“…The histological features of this type of soft tissue part OFMT suggest that it is a high cellular round cell lesion presented with a metaplastic bone peripheral film. In the described types of OFMT, there are three variants of it: one is benign (typical), second is malignant which carries the chances of disease recurrence or metastases and the third is atypical which does not meet the criteria of either typical or malignant 9. The malignant variant can also be called as extraskeletal osteosarcoma.…”

Ossifying fibromyxoid tumor of soft tissue: A case report with review of literature

“…However, the atypical form has an intermediate malignancy with a local aggressivity and recurrence [ [1] , [2] , [3] , [4] , 6 ]. The malignant form is considered as a sarcoma due to its aggressive behavior and its high risk of recurrence and metastasis with a rate of 20–60% [ 1 , 11 , 12 ]. The common metastatic sites are lung and soft tissue [ 1 , 4 , 6 , 12 ].…”