Benign nerve sheath myxoma D36.1

Harkin and Reed 1969

Dermal, also mucosal (oral mucosa area), solitary, soft papular or nodular neoplasm in children and adults of all ages, which is localized in the head-neck-torso area and the extremities and whose diagnosis generally proves to be a histological chance diagnosis. Also described as a tumour of the orbit.

Rare, reliable epidemiological figures do not exist; w>m.

All age groups (5 months - adults) are affected.

Mostly solitary, dermal/mucosal and/or subcutaneous/submucous, skin-coloured, soft nodules, rarely nodules of any other unspectacular aspect. The tumors are classified as cysts or dermal melanocytic nevi.

Dermally localized, well defined tumor fasciae, consisting of spindle, star-shaped cells with hyperchromatic nuclei. Occasionally also multinucleated giant cells. The histological image is dominated by a myxoid stroma. The mitosis rate is not increased. The tumor parenchyma is immunoreactive for the S-100 protein, for NGFR (nerve growth factor receptor) and NSE (neuron specific enolase), but negative for SMA (smooth muscle actin). Reactivity with Ki-67 <5%.

The cellular neurothekeoma is often equated with the myxoid neurothekeoma.

1. Avninder S et al (2007) Benign nerve sheath myxoma (myxoid neurothekeoma) in the leg. Dermatol Online J 13:14.
2. Fetsch JF et al (2007) Neurothekeoma: an analysis of 178 tumors with detailed immunohistochemical data and long-term patient follow-up information. Am J Surg Pathol 31:1103-1114.
3. Han TY et al (2016) A Rare Case of Atypical Myxoid Cellular Neurothekeoma in a 6-Year-Old Girl. Pediatrist Dermatol 33:e123-124.
4. Hornick JL et al (2007) Cellular neurothekeoma: detailed characterization in a series of 133 cases. At J Surg Pathol 31:329-340.
5. Li J et al (2014) Neurothekeoma of the thoracic and lumbar area in an adult man: A case report. Mol Clin Oncol 2:156-158.
6. Rodríguez-Uña I et al (2105) Orbital nerve seath myxoma with extraocular muscle involvement: a rare case. Semin Ophthalmol 30:316-320.
7. Yun SJ et al (2014) Myxoid Cellular Neurothekeoma: A New Entity of S100-Negative, CD68-Positive Myxoid Neurothekeoma. Ann Dermatol 26: 510-513.