Histologic mimics of malignant melanoma

Although spongiotic (eczematous), psoriatic and cutaneous skin infections are among the most common in dermatology consultations, melanocytic lesions - including the different types of nevi and melanomas - are among those that cause a great deal of concern and stress to patients and their clinicians. A diagnosis of benign melanocytic nevus carries a very good prognosis. However, a diagnosis of melanoma might indicate more aggressive treatment, lifelong surveillance and a worse prognosis. Differentiating between these conditions is not always a straightforward process for clinicians and pathologists. Therefore, knowledge of melanoma mimickers is very important for clinicians in general, and dermatologists and pathologists in particular. In this review, we called attention to some of the more frequent benign but unusual melanocytic lesions that are of diagnostic concern for clinicians evaluating these cutaneous proliferations.

Deep Penetrating Nevus / 대한피부과학회지

Deep penetrating nevus (DPN) is a distinctive melanocytic nevus firstly reported by Seab et al. in 1989. It is characterized by its dark pigmentation, occurring mostly on the face, neck, or shoulder, and usually measures less than 1 cm in diameter. Since it has histologic similarities with other cutaneous pigmented lesions such as combined nevus, blue nevus, Spitz nevus, and pigmented spindle cell nevus, it is often difficult to diagnose and it may be clinically and histologically mistaken for a malignant melanoma. There have been 2 reported cases of DPN in the Korean dermatologic literatures; therefore, we report a case of DPN mimicking malignant melanoma.

Deep penetrating nevus: A distinct variant of melanocytic nevus.

Deep penetrating nevus (DPN) is a variant of melanocytic nevus which goes unrecognized due to its relative rarity and may be misinterpreted as malignant melanoma. It commonly presents in young adults as a dark pigmented lesion on the face, neck, or shoulder. A 60-year-old lady presented with a mole over the left arm of 8 years duration. A biopsy of the lesion was performed under the clinical impression of a compound nevus with suspicion of malignancy. Based on the histologic features, a diagnosis of DPN was put forward.

A Case of Deep Penetrating Nevus / 대한피부과학회지

Deep penetrating nevus is a recently described variant of melanocytic nevi. It's clinical and histopathological features can be confused with malignant melanoma, blue nevus, Spitz nevus, pigmented spindle cell nevus, or congenital melanocytic nevus. Histopathologically, the lesions are characterized by loosely-organized nests of slightly to distinctively pleomorphic pigmented cells which deeply penetrate the reticular dermis and often extend into the subcutis. We report a case of deep penetrating nevus on the right arm of a 21-year-old female.

A Case of Deep Penetrating Nevus / 대한피부과학회지

Deep penetrating nevus is a distinctive entity first described by Seab et al. in 1989. This is a variant of melanocytic nevus found on the face, the upper part of the trunk, and the proximal part of the limbs of young adults. It is often deeply pigmented with some variegation in color, and it may lead one to a misdiagnosis of blue nevus or malignant melanoma. Histopathologically the lesions are composed of loosely organized nests of slightly to distinctively pleomorphic pigmented cells that deeply penetrated reticular dermis and often extended into the subcutis. There have been no report of deep penetrating nevus in the Korean literature. We report a case of deep penetrating nevus occurring on the chest in a 19-year-old male.