Spotty skin pigmentation and multiple blue naevi as cutaneous markers for spinal melanotic schwannoma

Abstract

SUMMARYSpinal melanotic schwannomas are rare spinal tumours with a very poor prognosis in terms of mortality due to difficulty in complete resection and local recurrences. A 67-year-old man presented with acute onset progressive paraparesis for 2 weeks. The patient also had spotty skin pigmentations (blue naevi) in his right lateral thigh. MRI revealed an intradural extramedullary enhancing lesion in the lower thoracic cord level. With a preoperative diagnosis of simple nerve sheath tumour excision was planned. At laminotomy, an infiltrating "en plaque" like lesion reaching up to mid and upper thoracic cord level was identified and excision was carried out. Postoperative histopathology was unique with the identification of melanin and presence of epitheloid cells, with the additional detection of psammoma bodies and adipose-like cells. Melanotic schwannomas though rare and carry poor prognosis must be borne in mind in patients with spotty skin pigmentation and acute onset limb weakness. BACKGROUND

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

“…[ 20 ] MS may arise anywhere along the peripheral nerves including along the sympathetic chain, GI tract, mediastinum, and subcutaneous areas. [ 20 , 40 ] Reports on the most common locations of MS are mixed, but along the spinal nerve sheath and within the cranium are considered to be the two most common. [ 3 , 32 , 61 ] Our review of the MS literature revealed 78 cases of sporadic spinal and 20 cases of intracranial MS.[ 39 ] Fewer than 20 cases of cutaneous MS have been described.…”

Melanotic Schwannomas Are Rarely Seen Pigmented Tumors with Unpredictable Prognosis and Challenging Diagnosis

“…While nonpsammomatous MS is considered to be a sporadic type, encountered in fourth decades, psammomatous melanotic Schwannoma tends to occur at an earlier age (average age, 22.5 years). Psammomatous type is associated with Carney Syndrome that is characterized by the presence of myxomas in the heart, breast, uterus, skin lentigines, endocrinopathy (Cushing's syndrome), growth hormone producing pituitary adenoma, epithelioid blue nevi, Sertoli cell tumors of the testis, tumors of the thyroid, and ductal adenomas of the breast [ 1 , 4 , 6 ]. MS does not necessarily demonstrate psammoma bodies.…”

“…MS derived from the spinal nerve root is characterized by slow growth and low aggressiveness and assumes a dumbbell appearance [ 6 ]. Conventional Schwannomas are hypointense on T1-weighted and hyperintense on T2-weighted sequences, contrary to melanotic Schwannomas which are hyperintense on T1-weighted and hypointense on T2-weighted sequences [ 3 , 4 ]. Our second case was hypointense on T1-weighted and hyperintense on T2-weighted sequences.…”

“…Optimal surgical approach is complete tumor resection which is not possible all the time, owing to the local infiltration and the need for adjuvant postoperative radiotherapy and chemotherapy to prevent local recurrences and metastases [ 4 , 5 ]. Our first case did not demonstrate recurrences or metastases for 30 months.…”

“…MS was first described by Hudson in 1961 with only 100 cases reported in the literature so far [ 3 ]. Most MS cases affect intracranial structures, followed by posterior nerve roots of the spinal canal, and rarely sympathetic chain, acoustic nerve, cerebellum, orbit, choroid, soft tissue, heart, oral cavity, esophageal wall, stomach, bronchus, retroperitoneum, uterine cervix, and parotid gland [ 3 , 4 ]. Spinal MS arises in the lumbosacral region (47.2%) and thoracic (30.5%) and cervical (22.2%) levels and rarely intramedullary types are seen.…”