Melanocytic Matricoma: A Potential Mimic of Malignant Melanoma.

Melanocytic matricoma is a rare dermal tumor that typically presents on the sun-damaged skin of older patients. While there is controversy in the literature regarding the proper characterization of this tumor, there are certain histological and immunohistochemical features that have been described. This report presents a case of melanocytic matricoma with several unusual features that were initially feared to be malignant melanoma. Careful histologic and immunohistochemical analysis was required to rule out malignant melanoma and make the correct diagnosis. Given the rarity of melanocytic matricoma and the potential for it to mimic malignant melanoma, it is important for pathologists to keep melanocytic matricoma on the differential and be aware of the clinical, histological, and immunohistochemical features of this tumor.

Histopathology of Measles: Report of 2 Cases With New Findings.

The authors report 2 cases of measles demonstrating novel skin pathology that may be useful in establishing early diagnosis. Syncytial epithelial giant cells, which are characteristic of measles, were found to be present in the dermis, indicating that these cells are not specific to the lymphoid tissue and epithelia of which they are classically attributed to. The cells were not prominent, and required step sectioning to observe. These results were confirmed by electron microscopy, which showed virus capsid particles within the endoplasmic reticulum, secretory vesicles, and cytoplasm of multinucleated cells. One of the cases also demonstrated an unusual mixed infiltrate of eosinophils and fibrin thrombi, which has not been previously described. Both patients in this report recovered with supportive therapy.

Elevated rates of transaminitis during ipilimumab therapy for metastatic melanoma.

Melanoma is the deadliest form of skin cancer. Ipilimumab, a novel immunotherapy, is the first treatment shown to improve survival in patients with metastatic melanoma in large randomized controlled studies. The most concerning side effects reported in clinical studies of ipilimumab fall into the category of immune-related adverse events, which include enterocolitis, dermatitis, thyroiditis, hepatitis, hypophysitis, uveitis, and others. During the course of routine clinical care at Mount Sinai Medical Center, frequent hepatotoxicity was noted when ipilimumab was administered at a dose of 3 mg/kg according to Food and Drug Administration (FDA) guidelines. To better characterize these adverse events, we conducted a retrospective review of the first 11 patients with metastatic melanoma treated with ipilimumab at the Mount Sinai Medical Center after FDA approval. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) elevation, as defined by the National Cancer Institute's Common Terminology Criteria for Adverse Events, each occurred in six of 11 cases (≥grade 1), a notably higher frequency than could be expected on the basis of the FDA licensing study where elevations were reported in 0.8 and 1.5% of patients for AST and ALT, respectively. Grade 3 elevations in AST occurred in three of 11 patients as compared with 0% in the licensing trial. All cases of transaminitis resolved when ipilimumab was temporarily withheld without administration of immunosuppressive medication. During routine clinical care of late-stage melanoma patients with ipilimumab, physicians should monitor patients closely for hepatotoxicity and be aware that toxicity rates may differ across populations during ipilimumab therapy.

Dermatology clinics: what's new in dermatopathology: news in nonmelanocytic neoplasia.

This article reviews the recent dermatopathology literature involving nonmelanocytic neoplasia, with a focus on important work done over the last 5 years. The discussion includes advances in the understanding of Merkel cell carcinoma pathogenesis and prognosis; changes in the seventh edition of the American Joint Committee of Cancer staging manual in reference to staging of squamous cell carcinoma and Merkel cell carcinoma; newly described or rare histopathologic patterns and entities including squamoid eccrine ductal carcinoma, rippled-pattern adnexal neoplasms, onychomatricoma, spindle cell predominant trichodiscoma/neurofollicular hamartoma, and myoepithelioma; and microsatellite instability in sebaceous neoplasms of Muir-Torre syndrome and other tumors.

Morphologic features of extrahepatic manifestations of hepatitis C virus infection.

Cirrhosis and hepatocellular carcinoma are the prototypic complications of chronic hepatitis C virus infection in the liver. However, hepatitis C virus also affects a variety of other organs that may lead to significant morbidity and mortality. Extrahepatic manifestations of hepatitis C infection include a multitude of disease processes affecting the small vessels, skin, kidneys, salivary gland, eyes, thyroid, and immunologic system. The majority of these conditions are thought to be immune mediated. The most documented of these entities is mixed cryoglobulinemia. Morphologically, immune complex depositions can be identified in small vessels and glomerular capillary walls, leading to leukoclastic vasculitis in the skin and membranoproliferative glomerulonephritis in the kidney. Other HCV-associated entities include porphyria cutanea tarda, lichen planus, necrolytic acral erythema, membranous glomerulonephritis, diabetic nephropathy, B-cell non-Hodgkin lymphomas, insulin resistance, sialadenitis, sicca syndrome, and autoimmune thyroiditis. This paper highlights the histomorphologic features of these processes, which are typically characterized by chronic inflammation, immune complex deposition, and immunoproliferative disease in the affected organ.

Fuzeon-induced collagenophagic granuloma: a peculiar granulomatous injection site reaction to Fuzeon--a case report and review of literature.

Enfuvirtide (ENF, T-20, or Fuzeon [Hoffman-La Roche Inc, Nutley, NJ, and Trimeris, Inc, Durham, NC]) is an HIV-1 fusion inhibitor and is the only injectable antiretroviral drug available. Injection site reactions (ISRs) are the most frequently reported adverse events, occurring in about 98% of patients. A granuloma annulare-like granulomatous ISR has been reported. We report a granulomatous ISR that is different from granuloma annulare and granuloma annulare-like reaction because it is rich in multinucleated giant cells engulfing altered collagen. We call this type of ISR a collagenophagic granuloma. Most previous reports-with the exception of 1 report-about ISRs with ENF treatment have used punch biopsies, which lack the depth to analyze the reticular dermis and subcutaneous tissue and, therefore, may have missed ISRs, which look like granuloma annulare, and the collagenophagic granulomatous reaction.