Ossifying fibromyxoid tumor: invariable ultrastructural features and diverse immunophenotypic expression.
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.Ear, nose, & throat journal 10/2012; 91(10):E15-7. · 1.03 Impact Factor
- Journal of oral and maxillofacial surgery: official journal of the American Association of Oral and Maxillofacial Surgeons 10/2010; 69(5):1355-60. · 1.58 Impact Factor
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ABSTRACT: Ossifying fibromyxoid tumor (OFMTs) of soft parts is a rare soft tissue and bone tumor of borderline malignancy displaying an uncertain line of differentiation. The existence of fully malignant OFMT is controversial. To better understand the natural history and line of differentiation taken by OFMT, we studied 46 cases by light microscopic, immunohistochemical (IHC), genomic, proteomic, and fluorescence in situ hybridization (FISH) methods. Cases were classified according to the 2003 Folpe and Weiss system. Clinical and follow-up information was obtained. IHC for S-100 protein, desmin, epithelial membrane antigen (EMA), cytokeratins, smooth muscle actin (SMA), INI-1, neurofilament protein (NFP), CD56d excitatory amino acid transporter-4 (EAAT4), and MUC4 was performed on formalin-fixed, paraffin-embedded (FFPE) tissues. Gene expression profiling and proteomic studies were conducted on FFPE tissues from 13 and 5 cases, respectively. FISH for INI-1 was performed on 10 cases. The 46 tumors arose in 29 men and 17 women (median age, 52 y; range 39 to 63 y) and involved the proximal (N=17) and distal extremities (N=13), head and neck (N=9), and trunk (N=5). Median tumor size was 5.4 cm (range, 1.0 to 21.0 cm). Cases were classified as typical OFMT (26 of 46, 57%), atypical OFMT (5 of 46, 11%), and malignant OFMT (15 of 46 cases, 32%). Clinical follow-up (27 cases, median 55 months' duration) showed all patients with typical and atypical OFMT to be alive without disease. Adverse events, including 3 local recurrences, 3 metastases, and 3 deaths, were seen only in malignant OFMT. IHC results were as follows: S-100 protein (30 of 41, 73%), desmin (15 of 39, 38%), cytokeratin (4 of 35, 11%), EMA (5 of 32, 16%), SMA (2 of 34, 6%), INI-1 (lost in mosaic pattern in 14 of 19, 74%), EAAT4 (31 of 39, 80%), MUC4 (3 of 14, 21%), NFP (8 of 10, 80%) and CD56 (6 of 14, 43%). Gene expression profiling showed typical and malignant OFMTs to cluster together, distinct from schwannian tumors. Proteomic study showed expression of various collagens, S-100 protein, and neuron-related proteins. FISH showed INI-1 deletion in 5 of 7 (71%) cases. We conclude that malignant OFMTs exist and may be recognized by the previously proposed criteria of Folpe and Weiss. Expression of neuron-related markers, in addition to Schwann cell and cartilage-associated markers, suggests a "scrambled" phenotype in OFMTs. Loss of INI-1 or other genes on 22q is likely important in the pathogenesis of these rare tumors.The American journal of surgical pathology 11/2011; 35(11):1615-25. · 4.59 Impact Factor