Clinical and histological effect of a single treatment of normal mode alexandrite (755 nm) laser on small melanocytic nevi.

BACKGROUND AND OBJECTIVE: Earlier studies on the treatment of congenital melanocytic nevi have reported the efficacy of Q-switched ruby laser and Nd:YAG lasers. In this study we evaluated the clinical and the histological effects of a single treatment of normal mode (3 msec) alexandrite laser (755 nm) on small melanocytic nevi. MATERIALS AND METHODS: Fourteen patients having 40 nevi entered into the study. Twenty six nevi were clinically followed up after laser treatment for 4 months. Fourteen nevi were biopsied after laser treatment: 8 nevi immediately, 3 nevi after 10 days and 3 nevi after 1 month. RESULTS: At the end of 4 months, 20 (76.92%) nevi attained moderate to significant lightening of color, 5 (19%) nevi had their color matching that of the surrounding skin, one nevus (3.85%) showed very mild hypopigmentation, and 18 (69%) nevi had a surface level similar to the surrounding skin. One nevus healed with keloid formation. Histologically, immediately following laser, there was necrosis of nevus cells in the papillary and uppermost reticular dermis. Nevus cells in the deeper layers of the dermis were not affected. Ten days following laser, the upper dermis showed granulation tissue. One month after laser, there was mild fibrosis in the upper dermis and persistence of nevus cells in the middle and deep dermis. CONCLUSION: These results suggest that normal mode alexandrite laser may clear or cosmetically improve small melanocytic nevi whether congenital or acquired. However, the concern about the recurrence of the nevi and the potential for malignant transformation should be addressed by long-term follow-up studies.

The spectrum of cutaneous granulomatous vasculitis: histopathologic report of eight cases with clinical correlation.

Cutaneous granulomatous vasculitis is an uncommon histopathologic finding that has been associated with lymphoproliferative disorders, systemic vasculitis, autoimmune inflammatory diseases, and infection. To define further the concept of cutaneous granulomatous vasculitis and to emphasize its clinical importance, we reviewed biopsy material from 8 patients seen from 1985 through 1992. All biopsies showed evidence of blood vessel damage with fibrinoid change or hemorrhage (or both) and granulomatous inflammation in and around vessel walls. Special stains for microorganisms were negative in all cases. Associated medical disorders included neuropathy (2 patients), sarcoid-like disease (2), systemic vasculitis (1), lymphoma and suspected lymphoma (1 each), and associated herpes simplex virus (1). T-cell gene-rearrangement studies were negative in a patient with suspected lymphoma. Granulomatous cutaneous vasculitis is most commonly associated with lymphoma and systemic vasculitis. In selected cases, infection should be considered as an underlying cause.

Mast cells, neutrophils, and eosinophils in prurigo nodularis.

BACKGROUND AND DESIGN: Prurigo nodularis is a disease of unknown cause. To characterize the involvement of mast cells, neutrophils, and eosinophils in lesional tissue, we analyzed seven skin biopsy specimens by an indirect immunofluorescence technique for localization of mast cell tryptase, neutrophil elastase, and eosinophil granule major basic protein, eosinophil cationic protein, and eosinophil-derived neurotoxin. RESULTS: Mast cells were detected in all of the specimens, with prominent numbers of mast cells in three specimens; there was minimal or no extracellular deposition of tryptase in any of the tissues. Neutrophil infiltration was observed in all specimens, but few cells were observed in four; extracellular elastase was minimal or absent in all but one specimen in which prominent dermal elastase deposition was found. Scanty eosinophil infiltration was present in all specimens; however, extracellular deposition of the eosinophil granule proteins including major basic protein, eosinophil-derived neurotoxin, and eosinophil cationic protein was present in all but one specimen and striking deposition of at least one eosinophil granule protein was present in six of the seven specimens. CONCLUSIONS: These studies suggest that mast cell numbers are increased in prurigo nodularis and that eosinophil degranulation as evidenced by striking extracellular deposition of granule proteins is prominent in lesions. In contrast, extracellular deposition of mast cell and neutrophil proteins is absent. The distinctive proteins of the eosinophil granule have potent effects on tissues; the toxicity of these proteins and their deposition in lesional tissue suggest a pathogenic role for the eosinophil in prurigo nodularis.

Benign lymphangioendothelioma.

We have studied eight cases of an acquired lymphatic endothelial lesion for which we propose the name "benign lymphangioendothelioma." The lesions developed as solitary, slowly extending, erythematous macules and plaques, usually occurring on the extremities or the shoulders in adolescents or adults. The characteristic histopathologic feature is permeation of the dermal collagen by flattened, endothelium-lined channels and spaces. Hemorrhage, iron deposition, and inflammation were not part of the lesion. Ulex europaeus agglutinin I labeled the lesional endothelial cells consistently, but factor VIII-related antigen labeling was negative. This histologic pattern and the special studies suggested a lymphatic lesion. Surgical excision, performed in six patients, was not followed by recurrence.

Woolly hair nevus.

Woolly hair nevus is a rare, nongenetically determined condition in which unruly and tightly curled hair is localized on one or several areas of the scalp. We report the first case of woolly hair nevus with onset during adolescence. Marked improvement was evident 5 years after onset. Light microscopic examination of a biopsy specimen from the scalp showed a curved hair follicle. Scanning electron microscopic examination revealed slight fluting and marked flattening of the hair shafts. A discussion of these results and a comparison with those of the previously reported cases suggest that woolly hair nevus correlates with a variety of structural changes in the hair.