Malignant Ossifying Fibromyxoid Tumor of the Parapharyngeal Space

Abstract

Ossifying Fibromyxoid Tumor (OFMT) is a rare, recently described tumor. As such, there is a paucity of information in the literature regarding this neoplasm. Most reports cite that the tumor most commonly occurs subcutaneously in the soft tissues of the extremities. 1-3 Additionally, OFMT has a predilection for men and exhibits a moderate recurrence rate (27%). 2 Malignant forms of the tumor are even rarer than their benign counterparts. At the time of manuscript preparation, the authors found only 27 reported cases of the malignant OFMT (versus 82 reports of benign OFMT). Similar to benign OFMT, most of the reported malignant cases occurred subcutaneously in extremities. However, a few uncommon locations have been described such as the mandible, 4 oral cavity, 5 and scalp. 6 While rare occurrences in the head and neck have been noted, to the authors' knowledge no such tumor has been reported in the parapharyngeal space. The authors present a case of a malignant ossifying fibromyxoid tumor in the parapharyngeal space.A 33-year old Pakistani male presented for evaluation for a two-year history of progressively enlarging right-sided neck mass. The patient also complained of gradual dysphonia but denied any dysphagia, odynophagia, snoring, stridor, trismus, or otologic symptoms. His past medical and surgical history were otherwise non-contributory. He did report a history of nicotine use, having smoked _ pack per day for the past 16 years. He denied daily alcohol consumption.On physical examination, the patient had symmetric palatal elevation, but the tonsillar fossae were asymmetrical (right buldge). With palpation of the neck, a firm right neck mass was detected, located anterior and deep to the right sternocleidomastoid and spanned from the angle of the jaw to the midlevel of the neck. Flexible nasopharyngolaryngoscopy revealed a slight bulge of the right pharyngeal wall and partial obliteration of the right piriform sinus (Figure 1). Vocal cord abduction and adduction was otherwise intact and symmetric.Magnetic resonance imaging (MRI) of the lesion indicated a 5.2 x 5.0 x 7.0 right neck mass extending from the skull base to the level of the thyroid cartilage ( Figure 2). It showed areas of cystic degeneration and enhancement with gadolinium. Magnetic resonance angiogram revealed lateral displacement of the right internal jugular vein anterior displacement of the external and internal carotid arteries. There was however, no splaying of the external and internal carotid arteries. Preoperative FNA was not performed secondary to the potential risk of bleeding associated with a suspected paraganglioma.The patient underwent uncomplicated right transcervical excision of the parapharyngeal lesion. Histopathologic analysis of the mass demonstrated features consistent with malignant OFMT. It demonstrated high nuclear grade and cellularity along with >2 MF/ 50 HPF . Immunohistochemical studies showed the presence of basal lamina, immunoreactivity of the neopastic cells to S-100 protein and glial fibrillary acidic treatment...

Malignant ossifying fibromyxoid tumor of the calvaria: illustrative case

“…1 While historically considered benign or indeterminate/ borderline malignant potential, frank malignant variants have been recognized and are considered part of the high-grade sarcoma spectrum. [2][3][4][5][6][7][8][9][10][11][12][13][14] While the exact differentiation cell line remains unknown, there is some evidence of putative Schwannian/neuroectodermal etiopathogenesis or myoepithelial/cartilaginous differentiation, 1,4,5,13,15,16 with a "scrambled phenotype" 10 being a leading hypothesis.…”