Multinucleate cell angiohistiocytoma: Case report and literature review.

Multinucleate cell angiohistiocytoma is a rare, vascular, fibrohistiocytic proliferation that has a benign but progressive course. The clinical presentation is that of grouped red-purple papules and nodules characteristically located on the lower extremities in women. The histopathology shows a proliferation of narrow vessels within thickened collagen bundles associated with multinucleate giant cells. These lesions are probably reactive in nature, and several mechanisms of pathogenesis, including hormonal, have been proposed. Different modalities, including intense pulsed light and pulsed-dye laser, have been used for treatment of these lesions. We report a case of a 74-year-old Caucasian woman with long-standing multinucleate angiohistiocytoma on her bilateral thighs that eluded diagnosis for several years. Upon biopsy and histopathological analysis, the diagnosis was made. Treatment options were entertained, although ultimately not pursued by the patient. We report this case to increase clinical awareness of this rare disease and to contribute to the ongoing literature aimed to further characterize this condition.

Acrokeratoelastoidosis and knuckle pads coexisting in a child.

Acrokeratoelastoidosis (AKE) is a marginal papular keratoderma that typically presents in childhood and young adulthood. Childhood cases have exhibited autosomal-dominant inheritance. Acrokeratoelastoidosis is distinct from other palmoplantar marginal papular keratodermas because of its characteristic dermal elastorrhexis with an overlying epithelial dell. We report an 11-year-old boy with multiple translucent hyperkeratotic papules in a linear fashion on the bilateral palmoplantar surfaces characteristic of AKE. He also presented with knuckle pads on the proximal and distal interphalangeal joints that rarely have been reported with AKE, suggesting that AKE and atraumatic knuckle pads may coexist.

Lichen Planus With Predominate Plasma Cell Infiltrate: Two Case Reports.

Lichen planus (LP) is a mucocutaneous inflammatory dermatitis of idiopathic origin that can involve the skin, mucous membranes, hair, and nails. LP has an associated set of characteristic histopathologic findings which include hyperkeratosis, vacuolization of the basal layer, Civatte bodies, wedge-shaped hypergranulosis, band-like lymphocytic infiltrate at the dermal epidermal junction, eosinophilic colloid bodies in the papillary dermis, and pigment incontinence. The infiltrate is usually composed of lymphocytes with few histiocytes, mast cells, and macrophages. The presence of plasma cell predominant infiltrate in LP has only been reported in four previous cases and 2 other cases of lichen nitidus. The authors report another 2 cases of LP with predominate plasma cell infiltrate in 2 female patients on the legs. The differential includes a drug-induced lichenoid reaction with predominate plasma cell infiltrate. However, there have been no case reports of that type of reaction. Because plasma cells are seen commonly in certain infectious diseases, malignancy, and macroglobulinemia, it is prudent to rule out those entities. Our patients responded well with a class 1 topical steroid, with improvement of their lower leg lesions within 1 month of treatment.

Merkel cell carcinoma: a review.

Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor of unknown origin that usually presents in the elderly population. A novel polyomavirus has been associated with a large percentage of tumors. Immune response plays an important role in pathogenesis of MCC. This article reviews the history, pathogenesis, presentation, and treatment of MCC. Future treatments also are discussed briefly.