Sonographic Features of an Ossifying Fibromyxoid Tumor of the Buttock

Abstract

n ossifying fibromyxoid tumor (OFMT) is a rare soft tissue neoplasm that presents as a solitary painless well-circumscribed mass usually located in the subcutaneous layer of the trunk or extremities. 1,2 The lesion mainly affects adults and is slightly predominant in men. 2 Almost all of the cases reported in the past were based on the clinical and histologic findings of OFMTs, with only a few reports about radiologic findings. To our knowledge, there have been no previous reports that described the sonographic features of this uncommon tumor. Here we describe the clinical, sonographic, and histologic findings in a case of an OFMT of the buttock. Case ReportA 24-year-old man came to our clinic with a nontender mass on his right buttock, which had been growing slowly for the past 6 months. On physical examination, there was a hard movable well-circumscribed mass that measured about 5.0 × 3.0 × 3.0 cm. Sonography of the central portion of the right buttock was done with an iU22 scanner and a 17-5 linear array transducer (Philips Medical Systems, Eindhoven, the Netherlands). It revealed a well-demarcated oval hypoechoic mass located just below the skin. There were marginal calcifications with posterior shadowing at both lateral aspects ( Figure 1A), and on color Doppler imaging, the inner portion showed an avascular lesion with posterior enhancement ( Figure 1B). The size of the mass was 4.3 × 2.9 × 1.9 cm. Muscle involvement and surrounding soft tissue infiltration were not seen. A presumptive diagnosis of an epidermoid cyst was made, and wide local excision of the mass was performed under spinal anesthesia with the patient in the prone position.

Ossifying fibromyxoid tumor in the lower extremity mimicking a sebaceous cyst. Case report and literature review

“…The proliferation fraction (Ki67) was less than 1%. Our case resulted to be of the typical variant as most of the reported OFMT cases in Table 1 [ [12] , [13] , [14] , [15] , [16] ], with the exception of two patients that were atypical and malignant variants respectively [ 10 , 11 ].…”

“…Our patient was booked for excision without further imaging. Interestingly, Table 1 reveals that US is not regularly used in the diagnosis of OFMT, where only two of the reported cases underwent preoperative US [ 12 , 13 ].…”

Tumeurs des tissus mous

“…Elle est formée de cordons ou de travées de cellules monomorphes sur un fond myxoïde . En échographie, outre les calcifications, elle présente un contenu hypoéchogène hétérogène [108] . Après exérèse, elle peut récidiver et métastaser [186] .…”

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

“…The clinical course of the disease is long, ranging from 1 to 20 years (10). OFMT is often characterized by an entire or incomplete fibrous pseudocapsule (5,11,12). In addition, an incomplete ossification ring is commonly observed in the periphery of the mass, while the boundary of the tumor is clear.…”