Spinal melanotic schwannomas

Abstract

Schwannomas are solitary, benign, slow-growing, encapsulated neoplasms composed of differentiated neoplastic Schwann cells. The melanocytic schwannoma, a schwannian tumor variant, is rarely encountered and its ocurrences have been described as single case reports 1 . The most common site of these tumors is the posterior spinal nerve root 1,2 . However, they can occur in other locations, such as the sympathetic chain, acoustic nerve, cerebellum, orbit, choroid, soft tissues, heart, oral cavity, esophageal wall, stomach, bronchus, retroperitoneum, uterine cervix and parotid gland 2,3 . The melanotic schwannomas can be related as a part of a syndrome named Carney complex (described in 1990), characterized by the association of cutaneous pigmentation, fibromyxoid tumors of the skin, myxoma of the heart, endocrine overactivity and autosomal dominant inheritance 4 . The largest series in spinal melanotic schwanommas is composed by 5 cases. In these series, we report our experience with three cases. CASESThree cases of spinal melanotic schwannoma were studied between 2006 and 2010 in authors' institution. None of the patients had a familial history or any component of Carney complex (spotty pigmentation, endocrine overactivity or myxomas).The patients were two male and one female. The mean age was 50 years (range 42-59 years). The most frequent symptom was pain followed by motor deficit. The mean duration of symptoms was 15 months. Magnetic resonance images showed intradural, extramedullary lesions iso/hyperintense in T1- (Fig A) and hypointense in T2-weighted sequences.The histological examination revealed fusiform and epithelioid cells, with highly pigmented cytoplasm ( Fig B). Immunohistochemical studies revealed intense cytoplasm and nuclear expression of S100 protein (Fig C), HMB-45 and Melan-A (Fig D). DiSCuSSionGenerally, melanotic schwannomas affect spinal nerves, the central nervous and the autonomous nervous system, but extra-nervous locations also occur 1 . The dorsal location represents 30.5% of the spinal melanotic schwannomas and clinical presentation is similar to other extramedullary spinal tumors 5 . Psammomatous melanotic schwannoma is a distinct clinicopathologic entity and may be considered as a part of the Carney complex, which is characterized by myxomas (heart, skin and breast), mucocutaneous spotty pigmentations and endocrine overactivity (due to thyroid dysfunction or hypophysial adenoma, or Cushing's syndrome secondary to primary pigmented nodular adrenocortical hyperplasia) 4 . About 50% of patients with melanotic psammomatous schwannomas are affected by the syndrome of Carney and one-fifth of them present multiple lesions 1 . None of our patients exhibits these manifestations.The preoperative diagnosis is based on magnetic resonance imaging. While conventional schwannomas are hypointense on T1-weighted and hyperintense on T2-weighted sequences, the melanotic variant is hyperintense on T1-and hypointense on T2-weighted sequences 1 . Zhang et al. 3 demonstrated that melanotic schwannomas rec...

Melanotic schwannoma of the lumbar spine: a case report and literature review

“…[1][2][3][4][5][6][7][8] We found a mean age of about 50 years old, the masculine gender being present in slightly more than half of the cases reviewed. The thoracic level was the most affected, with prevalence of extramedullary location (eight of the eleven reported cases), as well as in our patient, in which we found the development of extramedullary and intradural injury.…”

“…Regarding their recurrence potential, we found in the literature rates ranging from 18.2% 6 to 24%, 7 being almost always related to incomplete resections. [1][2][3][4]7 Moreover, studies have shown that among patients who were followed for more than five years, only slightly more than half were disease free at the end of follow-up, suggesting that long term monitoring is necessary to assess tumor recurrence and risk of metastasis. 10 …”

“…1 The melanocytic schwannoma is a variant of these neoplasms that occurs at younger ages compared to other schwannomas, being located in almost one third of cases in the posterior nerve root, 2,3 although it can also be found in soft tissue, heart, orbit, oral cavity, stomach, bronchi, retroperitoneum, cervix and parotid.…”

“…2,3 Magnetic resonance imaging (MRI) is the most commonly used image diagnosis test, revealing hyperintense T1 and hypointense T2 images, whereas in schwannomas of the non-melanocytic type, the immage pattern is the opposite. [2][3][4] In the literature, we found few cases of melanocytic type schwannoma in the spine, the largest series consists of five cases. 2 Thus, based on its extreme rarity, this paper aims to report a case of melanocytic schwannoma of the lumbar spine and conduce a brief literature review.…”

“…[2][3][4] In the literature, we found few cases of melanocytic type schwannoma in the spine, the largest series consists of five cases. 2 Thus, based on its extreme rarity, this paper aims to report a case of melanocytic schwannoma of the lumbar spine and conduce a brief literature review.…”