Intraneural Synovial Sarcoma Originating From the Median Nerve -Case Report-

Abstract

A 33-year-old female presented with a rare synovial sarcoma manifesting as a painful 12 × 15 mm tumor in the median palmar carpus. Preoperative neurological examination detected only radiating spontaneous pain in her right radial palm and decreased right grasping power. Magnetic resonance (MR) imaging confirmed the presence of the tumor. The preoperative diagnosis was schwannoma originating from the right median nerve. Subcapsular removal of the tumor was performed for preservation of the nerve function. However, postoperative histological and immunohistochemical studies suggested synovial sarcoma originating from the median nerve. No systemic metastasis was detected and the residual tumor capsule was totally removed. Local radiation therapy of 40 Gy, 2 Gy per day, was administered. Fourteen months later, local recurrence was detected on MR imaging. Total removal of the recurrent tumor was performed. Synovial sarcoma was finally diagnosed by the identification of SYT-SSX1 fusion gene transcripts using reverse transcriptase-polymerase chain reaction with a frozen tumor tissue sample.

Synovial sarcoma of nerve

“…Only 12 examples have been described to date [5][6][7][8][9][10][11][12][13][14][15]. This may not only reflect its true rarity in this anatomical location but may also reflect the natural tendency of pathologists to diagnose as "malignant peripheral nerve sheath tumor" (MPNST) all monomorphous, spindle cell sarcomas arising in nerve.…”

Intraneural Synovial Sarcoma of the Median Nerve in a 15-Year-Old Male: A Case Report and Review of Literature

“…Our patient is the youngest reported and had a 3-year disease free follow-up. 3,6-9 This case is particularly notable for rarity of disease, age of the patient, tumor location, and extent of nerve involvement.…”

“…Four of the 6 cases (including ours) reported monophasic histologic findings. 3,[6][7][8][9] However, interestingly the biphasic type is the most commonly reported histologic finding for all SSs. 9 Three cases reported patients that underwent total resection of the tumor and one who underwent extended resection.…”

“…Only 2 cases were positive for the SS18-SSX fusion gene. 3,[6][7][8][9] The treatment of SSs is multifaceted, often incorporating surgical resection, local radiation therapy, and chemotherapy. Primary, localized SS is approached with wide, local surgical resection.…”

Two malignant peripheral nerve lesions of non‐neurogenic origin

“…20,21,23 The imaging features of the mass were also non-specific, with a heterogenous, lobular mass arising from the nerve. An intranerual site for synovial sarcoma has been described 24,25 and like epithelioid sarcoma, it can show 'triple signal' due to the presence of haemorrhage and calcification, although it has a variable appearance and signal depending on size. Leiomyosarcoma and clear cell sarcoma have also been reported in an intraneural site.…”