Two Japanese cases of lichen planus pigmentosus-inversus

Authors


Aki Kashima, MD Department of Dermatology Faculty of Medicine University of Miyazaki 5200 Kihara Kiyotake Miyazaki 889-1692 Japan E-mail: akim@fc.miyazaki-u.ac.jp

Abstract

Case 1 was a 51-year-old Japanese woman. She presented with an asymptomatic brown macule located on the right axilla of 2 months’ duration. The smooth macule was 2 cm in diameter with a sharp demarcation (Fig. 1A).

Figure 1.

Figure 1.

Photographs of skin lesions in two patients. (A) Case 1. Well-circumscribed brown macule without an active red border in the central portion of the right axilla. (B) Case 2. Symmetric distribution of brown macules without an active red border in the popliteal fossae

Case 2 was a 62-year-old Japanese man. He presented with asymptomatic, symmetric, gray–brown macules located on the groin, axillae, and popliteal region of 6 months’ duration. The smooth macules were several millimeters to centimeters in diameter and sharply demarcated (Fig. 1B).

Oral or nail lesions, previous inflammatory processes in affected areas, and internal malignancies were absent. A causal relationship with drugs, recent sun exposure, or trauma could not be identified. Findings for work-up, including blood cell count, fasting blood sugar levels, liver function, serum electrolyte levels, serum electrophoresis, urinalysis, antinuclear antibodies, and serological examinations for human hepatitis viruses and syphilis, were within normal limits or negative. The lesions gradually disappeared without medication within 6 months.

Biopsy specimens showed a lymphocytic infiltrate with basal vacuolar changes and prominent melanin incontinence in the upper dermis (Fig. 2A). The band-like lymphocytic infiltrate was moderate in Case 1 and mild in Case 2. Immunohistochemistry showed infiltrative CD8+ T lymphocytes with keratinocytic damage, indicating cytotoxic injury of the keratinocytes (Fig. 2B). Both the epidermis and the upper dermis contained CD1a+ cells (Fig. 2C). The keratinocytes focally and weakly expressed HLA-DR (Fig. 2D). These findings were identical in samples from both patients.

Figure 2.

Figure 2.

Light and immunohistochemical microphotographs. (A) Mild, band-like, lymphocytic infiltrate with basal vacuolar change and prominent melanin incontinence in the upper dermis with apoptosis or necrosis of keratinocytes. (B) Epidermal infiltrate of CD8+ T lymphocytes with keratinocytic damage. (C) CD1a+ cells in the upper dermis. (D) Keratinocytes focally and weakly express HLA-DR (original magnifications: A, ×200; B–D, ×400)

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