Dermal nerve sheath myxoma of the hallux: a case report

Neurothekeoma: Another differential in the diagnosis of a subungual swelling

CASE

Lesions, which commonly grow and protrude beneath the distal end of a toe nail and present to the podiatrist or foot and ankle surgeon, include subungual exostosis or enchondroma and a Nora lesion. Neurothekeoma is a benign dermal tumour of the peripheral nerve sheath that usually affects the skin of the head, neck, shoulders and arms. It occurs less commonly in the lower limbs and has only been reported twice in a subungual location. A case of subungual neurothekeoma that recurred twice due to inadequate margins of resection is presented.

CONCLUSION

Although rare, neurothekeoma should be included in the differential diagnosis of a subungual lesion. Histopathological diagnosis is reached by differential immunostaining. Adequate clear margins of resection are recommended to prevent recurrence.

Nerve Sheath Myxoma in the Lower Extremity: A Rare Case with Description of Magnetic Resonance Imaging and Sonographic Findings

BACKGROUND This report is of a nerve sheath myxoma presenting as a slow-growing mass in the back of the left ankle of a 36-year-old man that was investigated by ultrasound and magnetic resonance imaging (MRI) before the diagnosis was confirmed by histopathology. CASE REPORT We report a nerve sheath myxoma of the ankle in a 36-year-old man. The palpable abnormality was falsely assumed to be a ganglion cyst prior to advanced imaging. Magnetic resonance imaging demonstrated a lobular mass with high T2 and intermediate T1 signal as well as moderate enhancement. T2 sequences also demonstrated distinctive internal septae. These internal septae were also noted on sonographic evaluation prior to biopsy. The patient was treated with surgical excision, and pathologic analysis showed myxoid nodules with loose arrangements of spindled cells separated by fibrous septae. S-100 protein and glial fibrillary acidic protein positivity by immunohistochemistry staining was demonstrated. Follow-up imaging at 12 months showed no evidence of tumor recurrence. CONCLUSIONS This case highlights that while nerve sheath myxomas are rare tumors, they should be considered in cases of cutaneous soft-tissue masses with myxoid imaging features. Ultrasound and magnetic resonance imaging features of thin internal septae may be present and correspond well with the unique histopathological characteristics of these lesions. This report shows the importance of imaging of peripheral soft-tissue masses, including ultrasound and MRI, which can identify localized and benign features and the solid, cystic, and myxoid areas, which were characteristic in this case of benign nerve sheath myxoma.

Neurothekeoma: report of a case in an infant and review of the literature

Neurothekeomas (nerve sheath myxomas) are uncommon benign tumors of nerve sheath origin. We describe an infant with a neurothekeoma and review the literature of neurothekeomas in children and adults. Neurothekeomas have been reported in 292 patients whose ages have ranged from 15 months to 84 years. They occur twice as often in women as in men. Neurothekeomas were most commonly located on the upper extremities and the head and neck. They also occurred on the trunk, the lower extremities, and mucosa. Histologic variants of neurothekeomas include classical, cellular, and mixed tumors. Surgical excision was the most common treatment. Recurrences were attributed to an incomplete excision; treatment of these tumors is by complete excision. Neurothekeomas should be included in the differential diagnosis of dermal nodules in infants and children.