We report two atypical cases of membranous aplasia cutis surrounded by a rim of hairs, one case associated with dense dermal melanocytosis and the other with naevus flammeus, with characteristic clinical features. A r...We report two atypical cases of membranous aplasia cutis surrounded by a rim of hairs, one case associated with dense dermal melanocytosis and the other with naevus flammeus, with characteristic clinical features. A rim of hypertrichosis, ‘hair collar’sign, is proposed to have a close association with neuroectodermal defects. A failure of the normal closure of the cranial neural tube might have affected foetal skin development, including melanoblast migration and capillary network formation. The changes in the present cases, as well as the hair collar sign may suggest a complex hamartomatous nature of membranous aplasia cutis.展开更多
Background: Neurofibromatosis, type 1, is associated with cutaneous melanin pigmentation, but an association with ordinary melanocytic nevi has not been described. Methods: This retrospective case-control study was de...Background: Neurofibromatosis, type 1, is associated with cutaneous melanin pigmentation, but an association with ordinary melanocytic nevi has not been described. Methods: This retrospective case-control study was designed to see if neurofibromas in patients with neurofibromatosis, type 1 (NF-1) differ from sporadic neurofibromas (SN) in their incidence of associated melanocytic nevi and other histologic features. Slides from 114 NF-1 were compared with 112 SN and 300 intradermal melanocytic nevi (IDN). Results: Small lentiginous melanocytic nevi were identified over 13 NF-1 (11%) but no SN (P=0.0002). Compared with other NF-1, NF-1 with nevi were more frequently associated with melanocytic hyperplasia, giantmelanosomes and diffuse neurofibroma (P < 0.03). Compared with SN, NF-1 were also more frequently assoc iated with melanocytic hyperplasia, lentigo simplex-like changes, diffuse neuro fibroma and plexiform neurofibroma (P < 0.001). Sebaceous hyperplasia (14%), de rmal elastosis (9%), lipomatous change (8%), epithelial cysts (4%) and kerati n granulomas or folliculitis (3%) were not significantly different in prevalenc e between NF-1, SN and the control group of IDN. Conclusions: This study sugges ts that there is a difference in the potential for melanocytic proliferation in NF-1 compared with SN. NF-1, SN and IDN are associated with a similar range of incidental histologic changes.展开更多
文摘We report two atypical cases of membranous aplasia cutis surrounded by a rim of hairs, one case associated with dense dermal melanocytosis and the other with naevus flammeus, with characteristic clinical features. A rim of hypertrichosis, ‘hair collar’sign, is proposed to have a close association with neuroectodermal defects. A failure of the normal closure of the cranial neural tube might have affected foetal skin development, including melanoblast migration and capillary network formation. The changes in the present cases, as well as the hair collar sign may suggest a complex hamartomatous nature of membranous aplasia cutis.
文摘Background: Neurofibromatosis, type 1, is associated with cutaneous melanin pigmentation, but an association with ordinary melanocytic nevi has not been described. Methods: This retrospective case-control study was designed to see if neurofibromas in patients with neurofibromatosis, type 1 (NF-1) differ from sporadic neurofibromas (SN) in their incidence of associated melanocytic nevi and other histologic features. Slides from 114 NF-1 were compared with 112 SN and 300 intradermal melanocytic nevi (IDN). Results: Small lentiginous melanocytic nevi were identified over 13 NF-1 (11%) but no SN (P=0.0002). Compared with other NF-1, NF-1 with nevi were more frequently associated with melanocytic hyperplasia, giantmelanosomes and diffuse neurofibroma (P < 0.03). Compared with SN, NF-1 were also more frequently assoc iated with melanocytic hyperplasia, lentigo simplex-like changes, diffuse neuro fibroma and plexiform neurofibroma (P < 0.001). Sebaceous hyperplasia (14%), de rmal elastosis (9%), lipomatous change (8%), epithelial cysts (4%) and kerati n granulomas or folliculitis (3%) were not significantly different in prevalenc e between NF-1, SN and the control group of IDN. Conclusions: This study sugges ts that there is a difference in the potential for melanocytic proliferation in NF-1 compared with SN. NF-1, SN and IDN are associated with a similar range of incidental histologic changes.
