Parachordoma of Soft Tissues of the Arm

Abstract

Parachordoma, or myoepithelioma, is a very rare tumor histologically resembling chordoma but occurring in the nonaxial soft tissues. It typically has an indolent nature, with occasional late recurrence and even rare metastases. Review of existing literature reveals a male predilection, with the tumor typically occurring in the fourth decade of life in the lower extremity. It typically is managed with wide resection. We report the case of a 60-year-old woman with a right distal upper arm parachordoma treated with wide resection of the tumor.

Clinical and Radiological Presentations of Pelvic Parachordoma

“…3,4 According to previous studies, 3,5 the majority of the tumors arise from the extremities and the most common symptom is painless swelling. Few cases complain of localized pain.…”

Parachordoma of Soft Tissues of the Arm: A Very Rare Tumour

“…The destruction of adjacent osseous structures seen in our case is highly unusual; only two similar cases have been reported in the literature [3, 4]. On MRi, the lesion appears as hypo- or isointense on T1-weighted sequences and as hyperintense on T2 and STIR images [2–4]; it can sometimes be surrounded by edematous soft tissues [2]. …”

“…The condition affects both sexes, although it is slightly more common in males than in females. Mean age at presentation is 34.4 years (range: 4–86) [2]. …”

“…The most common location of parachordoma is the soft tissues of the extremities (78%), followed by the chest, the trunk, and the pelvis [2]. Clinically, it presents as a painless slow-growing nodular mass, which means that it usually goes unnoticed, and so diagnosis is normally established at a late stage.…”

“…Although some authors claim that both conditions are in fact the same entity [6], the current state of the art is to regard them as two different neoplasms on the basis of their immunohistochemical and cytogenetic characteristics. Both tumors are positive for S-100 protein and the epithelial membrane antigen (EMA), but they differ in the expression of cytokeratins, with CK-10 and CK-19 eliciting a positive reaction in chordoma and a negative reaction in parachordoma [2, 7, 8]. In addition, only chordoma expresses the T-box transcription factor Brachyury, which participates in mesoderm differentiation and axial development [9].…”