[Paresthetic notalgia and multiple endocrine neoplasia type 2a (Sipple's syndrome): 3 cases].

INTRODUCTION: Notalgia paresthetica is an isolated sensory mononeuropathy. Patients have a pruritus in the mid-upper back. Its association with multiple endocrine neoplasia type IIA has been reported in a few cases. We report three cases of this association.

CASE REPORTS: Case n(o) 1: A 45 year-old woman had multiple endocrine neoplasia type IIA with a medullary thyroid carcinoma and a primary hyperparathyroidism; she had a mid-upper back pigmented lesion. Histological examination showed dermal melanosis and deposits of amyloid in the dermis. Case n(o) 2: A woman had a multiple endocrine neoplasia type IIA which was diagnosed at the age of 60; she had a surgical treatment for a pheochromocytoma, a medullary thyroid carcinoma, and a primary hyperparathyroidism; she had dermatological examination for a pruriginous lesion of the mid-upper back. Case n(o) 3: The daughter of the patient n(o) 2 had had a surgical cure for a medullary thyroid carcinoma and a pheochromocytoma at the age of 31; she had a papulous and pruriginous lesion in the left scapular area. Her daughter and her sister had a multiple endocrine neoplasia type IIA without notalgia paresthetica.

DISCUSSION: Notalgia paresthetica is a benign cutaneous disorder which can be associated with multiple endocrine neoplasia type IIA. It can be considered that notalgia paresthetica is an early clinical marker of multiple endocrine neoplasia type IIA. Patients with a familial history of notalgia paresthetica or with an onset of notalgia paresthetica in childhood should be screened for multiple endocrine neoplasia type IIA. Patients with multiple endocrine neoplasia must also been screened for notalgia paresthetica because its finding is an argument for a familial form of multiple endocrine neoplasia type IIA. Dermatologists should be aware of this association.