Spinal myxomas: review of a rare entity

Abstract

Intramuscular myxomas are rare, benign mesenchymal tumours, occurring predominantly in large skeletal muscles as large, slow-growing and painless masses. Spinal occurrence is rare, and may present incidentally, or diagnosed via localized symptoms secondary to local infiltration of surrounding structures. Differential diagnosis based on imaging includes sarcomas, meningiomas and lipomas. We discuss two contrasting cases presenting with well-circumscribed cystic paraspinal lesions indicative of an infiltrative tumour and discuss the radiological and histological differences that distinguish myxomas from similar tumours. Surgical resection of the tumour was performed in both cases, however one patient required surgical fixation due to bony erosion secondary to tumour infiltration. Immuno-histopathological analysis confirmed the diagnosis of a cellular myxoma. Follow up imaging at 6 months confirmed no symptomatic or tumour recurrence in both cases. Histological analysis is the definitive means for diagnosis to differentiate myxomas from other tumours. Recurrence is rare if full resection is achieved.

Figure 1

Pre-operative T1 and T2 weighted MRI: left-sided extra-axial mass at C4/5 hypointense on T1 and hyperintense on T2.

Figure 2

Histological staining of intraoperative tumour smears: (A) intraoperative smear Toluidine blue stained slide. (B): H&E ×10. (C): H&E ×10. (D): vimentin IHC ×10.

Figure 3

Pre-operative T1 post Gadolinium and T2 weighted MRI: left-sided extra-axial mass at C5/6 with heterogenous enhancement on T1 and hyperintense on T2. Moderate compression of the spinal cord and invasion into surrounding soft tissue.

Figure 4

Tumour specimen resected en bloc. Solitary, relatively well-delineated nodule covered by a thick capsule measuring 30 × 25 × 20 mm.

Figure 5

PRISMA flow of literature search.