The American Journal of dermatopathology
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Piezogenic papules are lesions that occur on the feet and wrists because of the herniation of fat through the dermis. These papules can be painful or completely asymptomatic. ⋯ We report a case of a piezogenic papule simulating angiomyxolipoma on histological examination. The presented case suggests the possibility of an association between herniated fat tissue and mucin deposition with vascular proliferation.
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Minocycline has been used in the treatment of leprosy since the demonstration of its efficacy in inhibiting Mycobacterium leprae growth in 1987. Hyperpigmentation, a well-documented adverse effect, classically shows 3 clinical and histological patterns: type I consists of blue-black pigmentation in areas of current or previous inflammation, type II consists of blue-gray pigmentation of normal skin, often seen on the legs, and type III consists of diffuse muddy-brown pigmentation accentuated on sun-exposed sites. Whereas type I hyperpigmentation stains positively for hemosiderin and type III hyperpigmentation stains positively for melanin, type II hyperpigmentation stains positively for both. ⋯ Biopsies from both patients demonstrated deposition of brownish-black pigment granules within the cytoplasm of foamy histiocytes that was highlighted by both Perls and Fontana-Masson stains. Given the clinical and histological findings in our patients, it is as yet unclear whether this coexistent type I clinical pattern and type II histopathologic pattern of pigmentation is unique to multibacillary leprosy. These findings provide support for the existence of additional subtypes of minocycline-induced hyperpigmentation that do not adhere to the classic 3-type model described.