Nerve Sheath Myxoma Involving the Medial Rectus Muscle: A Case Report

Abstract

A 63-year-old man reported a 2-year history of painless OS proptosis. The first MRI, performed in the institution of origin, resulted in a diagnosis of hemangioma versus orbital pseudotumor. Examination revealed proptosis and mild chemosis. Ancillary tests were normal, and oral prednisone was initiated without remarkable changes. Later, an incisional biopsy identified the lesion as an intramuscular myxoma of the left rectus, and a new MRI was ordered. It described a fusiform thickening of the medial rectus with and exophytic growth below the inferior rectus and upward toward the superior oblique. Due to the localization of the lesion, a combined transcaruncular and swinging eyelid approach with a lateral orbitotomy was performed. Histopathological examination revealed a proliferation of stromal origin composed of myxoid matrix with fusocellular and stellate-shaped cells. Cells were S-100, CD34, and CD56 positive and negative for epithelial membrane antigen, CD68, CD10, actin, and desmin. Results were consistent with a left medial rectus nerve sheath myxoma.

Resection of Orbital Myxoma With Magnetic Resonance Imaging Evidence of Ethmoid Sinus Origin: Case Report and Review of 20 Patients in the Literature

“…A sufficient description was found in 20 patients with orbital myxoma (Table 1). 3,4,[6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] As summarized in Table 1, 21 patients, including the present patient, were 12 males and 9 females with the age at the initial presentation ranging from 10 to 75 years (median, 50 years). The initial symptoms were proptosis in 14 patients, eyelid swelling in 5, diplopia in 5, blepharoptosis in 1, headache in 1, and visual loss in 1 (duplicated symptoms in some patients).…”

“…Famous sites of the neoplastic origin are the atrium of the heart as cardiac myxoma 1,2 and also the jaw bone as gnathic myxoma. In the field of the face and head, myxoma has been rarely detected in the orbit, [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] cornea, 23 and conjunctiva [24][25][26][27] of the ocular surface, eyelid, [28][29][30] nasal cavity, and paranasal sinuses. [31][32][33][34][35][36][37][38][39][40] We experienced a patient with orbital myxoma who showed connection with the ethmoid sinus lesion in the follow-up period of 20 years before and after surgical resection of the orbital lesions.…”

“…We also reviewed 20 patients with orbital myxomas in the literature to know their clinical features. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]…”

“…We also reviewed 20 patients with orbital myxomas in the literature to know their clinical features. 3 - 22 …”