Search

Pigmented nevi, if excised incompletely, often recur and occasionally cause concern to the patient and the physician. In this study of 175 recurrent nevi from 173 patients, the clinical, gross, and microscopic features of recurrent nevi are described and criteria for diagnosis are developed. Rarely, recurrent nevi have atypical features that suggest malignant melanoma. The differential diagnosis entails clinical and histologic criteria that are presented.

A 60-year-old black woman had a large hyperkeratotic lesion and multiple smaller hyperkeratotic papules and plaques on the lower part of her legs in areas of erythema ab igne. Histologic examination of the largest lesion showed hyperplastic carcinoma in situ and the multiple smaller lesions showed varying degrees of squamous cell atypia and dermal elastosis. Histologically, these lesions were identical to solar-induced atypia, indicating that squamous cell carcinoma arising in erythema ab igne may be biologically similar to actinic carcinoma. Discussed here are clinical and histologic features of the thermal-induced lesions and other types of thermal-induced carcinomas.

The neoplastic system of human cutaneous melanoma includes three generaly recognized variants: lentigo maligna, superficial spreading melanoma, and nodular melanoma. Lentiginous melanomas other than lentigo maligna constitute a fourth group, of which plantar lentiginous melanoma qualifies as an anatomic subgroup. Histologically and clinically, plantar lentiginous melanoma (PLM) is characterized by a period of radial growth and often by one or more foci of regression. In 27 of 33 plantar melanomas, a characteristic lentiginous, radial component of melanocytic proliferation was noted. In the remaining six cases, histological material failed to document a radial component. Eighteen of the 27 patients with PLM were blacks, and 18 patients died of distant metastasis. Tumors invasive to level II did not metastasize, but at levels IV and V and in tumors with a high mitotic rate, the prognosis was poor. The presence of lymph node metastases at the time of initial therapy correlated with a poor prognosis group.