Ossifying fibromyxoid tumor: invariable ultrastructural features and diverse immunophenotypic expression.

Department of Pathology, Saitama Medical School, Saitama, Japan.
Ultrastructural Pathology (Impact Factor: 1.13). 01/2007; 31(3):233-9. DOI: 10.1080/01913120701351157
Source: PubMed

ABSTRACT Ossifying fibromyxoid tumor (OFMT) is a rare enigmatic soft tissue tumor, the origin of which is still uncertain. The authors report on 3 cases of OFMT arising in the trunk and head and neck regions of adults. Two recurred and one was suspected to have metastasis. All tumors consisted of multiple nodules, in which round or polygonal tumor cells were arranged in sheets or cords within a fibromyxoid background. Characteristic shell-like bone tissues were recognized in all tumors. Based on the grading system proposed by Folpe et al., 2 cases were designated as malignant OFMT and 1 as typical. In addition to S-100 protein, cytokeratin and neuronal markers (neurofilament, CD56 or CD57) were detected in 1 and 2 tumors, respectively. The salient and invariable ultrastructural features included reduplicated basal laminas, which seem to be crucial for the diagnosis.

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    ABSTRACT: Ossifying fibromyxoid tumor (OFMT) is a rare, recently described entity. As such, there is a paucity of information in the literature regarding this neoplasm. According to most reports, the tumor usually develops subcutaneously in the soft tissues of the extremities. Malignant forms of the tumor are far more rare than their benign counterparts. We present a new case of a malignant OFMT of the parapharyngeal space in a 33-year-old Pakistani man. The tumor was excised, and the patient did well with no complications. This case represents a rare occurrence of OFMT of the parapharyngeal space.
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