Melanocytic hyperplasia in scars. A histopathological investigation of 722 cases.

We studied 722 reexcision scars of benign and malignant lesions (except melanocytic lesions) excised over a 24-month period. The formalin-fixed, paraffin-embedded tissue sections were examined histologically and immunohistochemically. The histological features of melanocytic hyperplasia were present in 59 cases (8%), 56 from the sun-exposed skin of the face and neck and three from the trunk [p < 0.00001]. The most common sites were the nose and lower eyelids, but the forehead was also frequently involved. Of the 59 patients, 41 were women (p < 0.0001). Basal cell carcinoma was the most frequent original lesion in both sexes (80%). No melanocytic hyperplasia was found in 663 cases (298 on the trunk and extremities and 365 on the head and neck). We have seen this reaction pattern following reexcision of melanocytic lesions as well. Thus, interpreting reexcision margins when lentigo maligna or similar lesions are reexcised may be fraught with difficulty. It is important for pathologists and dermatopathologists to recognize this phenomenon because histologically the presence of increased numbers of large melanocytes could be misinterpreted as melanoma in situ.

[Cutaneous large cell anaplastic Ki-1 (CD 30) positive T-cell lymphoma]. / Kutanes grosszellig-anaplastisches Ki-1 (CD 30) positives T-Zell-Lymphom.

A 72-year-old female patient presented with a large ulceration on the lower half of her right abdomen. Cutaneous anaplastic large-cell lymphoma was diagnosed based upon histopathological and immunohistochemical features. There were no signs of extracutaneous involvement by the lymphoma. Complete remission was achieved by local electron beam radiation, followed by chemotherapy.

Spindle-cell lipoma of the skin.

Spindle-cell lipoma of the skin is a distinct lesion that can occur in the dermis or subcutaneous tissue. The most important aspect of histologic differential diagnosis of this benign tumor is the exclusion of liposarcoma. We report two cases of spindle-cell lipoma, in which the clinical features of these lesions did not deviate appreciably from those of the usual lipomas. However, their microscopic appearances differed in terms of the distinctive spectrum of histological growth patterns. The clinical, immunohistochemical, and light and electron microscopic features of both cases were studied and compared with those of conventional lipoma and liposarcoma. Immunohistochemically both tumors showed no expression of insulin-like growth-factor receptors I and II. Coexpression of these receptors is usually observed in liposarcomas.

Cutaneous melanoma in a patient with neurofibromatosis: a case report and review of the literature.

We report the occurrence of a malignant melanoma in a patient with neurofibromatosis (von Recklinghausen's disease; NF 1). Neurofibromatosis, like malignant melanoma, is believed to be a disorder of neural crest origin, and is associated with a number of different malignancies, but a definite association between cutaneous malignant melanoma and neurofibromatosis has not been established. We describe a patient with a malignant melanoma and with neurofibromatosis, and review the literature pertinent to this topic. The malignant melanoma was not related to a café-au-lait patch or congenital naevus. The paucity of reports of patients with neurofibromatosis associated with cutaneous malignant melanoma suggests that these diseases probably do not occur together with any greater frequency than that determined by chance alone.