Spitz/Reed nevi: a review of clinical-dermatoscopic and histological correlation

[Reed nevus and cutaneous melanoma in children: an immunohistochemical study]

Certain difficulties arise in the differential diagnosis between Reed nevus that is common in children and adolescents and cutaneous melanoma that is extremely rare in patients of this age group. In addition to the classical histological examination, an immunohistochemical test for marker proteins is carried out to improve the accuracy of the diagnosis of pigmented skin neoplasms.

OBJECTIVE

To evaluate the suitability of a set of proteins (cyclin D1, p16^INK4a, and HLA class I antigens) in the differential diagnosis of Reed nevus and cutaneous melanoma in children and adolescents.

MATERIAL AND METHODS

Three samples of pigmented skin neoplasms were taken during surgical treatment in patients at the Blokhin National Medical Research Center of Oncology: two samples of Reed nevus (from a 9-year-old girl and a 15-year-old boy) and a sample of cutaneous melanoma that had developed in an 8-year-old boy. The materials were presented by paraffin blocks. Immunohistochemical staining was performed using antibodies against cyclin D1, p16^INK4a, and HLA class I antigens.

RESULTS

Differences were found between nevus and melanoma in the expression of all three markers. Thus, the nuclear expression of cyclin D1, a proliferation activator, occurred in some cells in the nevus samples and in the vast majority of cells in the melanoma samples. The nuclear expression of the cell cycle inhibitor p16^INK4a was dramatically reduced in melanoma compared to nevus. HLA class I antigens were detected on the surface of individual nevus cells, but were completely absent on the membranes and in the cytoplasm of melanoma cells, which could promote the evasion of this tumor from the body's immunological supervision.

CONCLUSION

Immunohistochemical test for the proteins cyclin D1, p16^INK4a, and HLA class 1 antigens is a promising approach to differentially diagnosing between Reed nevus and cutaneous melanoma in children and adolescents.

Mimics of melanoma in reflectance confocal microscopy

The diagnosis of melanoma is challenging for both dermatologists and oncologists. Incidence of melanoma increases at a rate of 3-7% per year. Usage of modern tools such as dermoscopy and in vivo reflectance confocal microscopy improve early diagnosis and can save a life. There are a few melanoma simulators which can cause confusion and mislead in the differential diagnosis. This study aims to present skin lesions which can be similar to melanoma in confocal microscopy and to emphasize the importance of a detailed differential diagnosis. We describe five melanocytic lesions similar to melanoma and misleading confocal features. Although in vivo reflectance confocal microscopy is very useful in differentiating melanocytic lesions, histopathology evaluation in cases of melanoma mimics is definitive.

The color of skin: black diseases of the skin, nails, and mucosa

Gradations in skin color are a consequence of differing amounts of melanin and their varying distribution. Although many darkly pigmented skin lesions are melanocytic and can be attributed to melanin content, the color of a black lesion can also be due to blood, necrotic tissue, or exogenous pigment. The source, pattern, and distribution of the color in black lesions usually offer important insight into its etiology. This contribution reviews conditions that can take on a black color, discussing the cause of the hue and any additional impact sun exposure may have.

THE FAST CLINICAL EVOLUTION OF A SPITZ NEVUS: THREE-YEAR FOLLOW-UP OF A CHILD

Objective:

To report the clinical evolution and handling of a Spitz nevus, from its initial flat feature to becoming an irregular, nodular, reddish lesion.

Case description:

Female child, phototype II, with a small congenital nevus on the left lower limb and other sustained small nevi. The patient went through annual clinical and dermoscopic evaluations between the ages of three and seven, period during which the nevi located on the left thigh grew rapidly. The clinical hypothesis was Spitz nevus, with indication of surgical removal with a safety margin and anatomopathological study. Considering patient’s age and clinical/histological aspects, the diagnosis of Spitz nevus was confirmed.

Comments:

Initial globular pattern and size under 5 mm upon dermoscopy allowed clinical follow-up. However, onset of hyperchromia and rapid growing of the lesion, along with aesthetic concerns, possibility of trauma in the region, and risk of malignancy at puberty guided the decision of total resection and follow-up for recurrence.

Pigmented Spindle Cell Nevus of Reed of the Eyelid

Purpose

To report the clinical, pathological, and immunohistochemical features of the first pigmented spindle cell nevus (PSCN) of Reed documented to have appeared in the eyelid.

Methods

The findings of clinical and histopathological examination are presented, along with differential diagnoses and a review of the pertinent literature.

Case

A 3-year-old boy presented with a rapidly growing, heavily pigmented left lower lid papule raising the concern of malignancy, warranting excisional biopsy. Nests of predominantly junctional Mart-1-positive spindle cells were identified by histopathological examination. The cells were largely uniform in size, elongated, surrounded by granular and coarse melanin, with a Ki-67 proliferation index of 0-2%. Five-month follow-up did not evidence any recurrence or invasive behavior of this benign melanocytic tumor.

Conclusion

This is the first documented case of PSCN of Reed, a distinct entity from Spitz nevus, presenting in the eyelid. The differential diagnoses include spindle cell and superficially spreading malignant melanoma as well as dysplastic nevus. Integration of clinical and histopathological findings with immunohistochemical and fluorescence in situ hybridization markers plays a central role in the diagnosis.