Hemorrhagic spinal melanotic schwannoma presenting as acute chest pain: A case report and literature review

Abstract

Background: Melanotic schwannoma (MS) is a rare variant of peripheral nerve sheath tumor. MS commonly arises along the spinal nerve sheath. Patients most often experience pain along the dermatome of the affected nerve root. Symptoms development is usually insidious. About half of MS cases are associated with Carney complex, a multi-neoplastic disorder. The remaining cases arise spontaneously. About 10-44% of these tumors undergo malignant transformation.

Case description: We describe a case of hemorrhagic MS presenting as acute chest pain mimicking myocardial infarction, a presentation which has not yet been described in the literature. Neurologic examination did not reveal any abnormalities. Myocardial infarction was ruled out in the ER, and a chest CT angiogram was ordered for evaluation of PE or aortic dissection which revealed an intradural extramedullary dumbbell-shaped mass extending through the left vertebral foramen at the level of T8. MRI revealed a heterogenous mass that was hyperintense with T2 and hypointense with T1-weighted imaging. The patient underwent an open laminectomy of the left T8 and T9 vertebrae and gross total resection (GTR) of a hemorrhagic black tumor. Microscopic examination showed fascicles and nests of plump spindle cells with variable intracellular melanin. Immunohistochemistry showed the cells to be positive for S100, SOX10, HMB-45, and MART-1, confirming diagnosis of MS. Two months after the operation, the patient was doing well and is free of recurrence.

Conclusion: GTR is considered the optimal treatment for MS; radiotherapy and chemotherapy may be considered but have not been shown to improve patient outcomes.

Keywords: Carney complex; Melanotic schwannoma; Nerve sheath; Spinal neoplasia.

Figure 1:

(a and b) Sagittal T2-weighted MRI scans taken at the time of presentation show a slightly hyperintense heterogeneous mass at the level of T8-T9. (c and d) T1-weighted MRI scans taken after gadolinium administration show a hypointense mass with circumferential enhancement. Axial T1 (e) and T2 (f) images show an extramedullary intradural dumbbell-shaped mass.

Figure 2:

Intraoperative view of the dark, dumbbell-shaped tumor with apparent hemorrhage within the dural sac near the left T8 spinal nerve.

Figure 3:

(a) Tumor is circumscribed with cells in fascicles and nests. (b) Fascicles and nests composed of plump spindle cells. (c) Adipose-like cells admixed with tumor cells. (d) Melanin pigment deposition in the tumor cells (hematoxylin-eosin, original magnifications ×40 (a), ×100 (b), ×200 (c and d)).

Figure 4:

(a) S100 expression in tumor cells. (b) SOX10 expression in tumor cells. (c) HMB-45 expression in tumor cells. (d) MART-1 expression in tumor cells (original magnification ×100 (a through d)).

Figure 5:

Sagittal (a) and axial (b) T2-weighted MRI images taken 2 months after the removal of a spinal MS tumor.

Figure 6:

Bar graph visualizing reported cases of sporadic spinal melanotic schwannoma organized by primary nerve root affected. Each shade represents one of the four spinal segments.

Figure 7:

Box plot showing quartiles of patient age in reported cases of sporadic spinal melanotic schwannoma.