Concurrent Langerhans cell histiocytosis and acute myeloid leukemia: A rare presentation of a rare case.

A 72-year-old woman with no significant past medical history was admitted to the hospital for new-onset of leukocytosis with neutropenia, anemia, and thrombocytopenia, as well as a pruritic skin eruption. She was found to have acute myeloid leukemia (AML) with myelomonocytic differentiation. Her skin eruption consisted of widespread hemorrhagic crusted papules on the scalp and trunk. A skin biopsy was performed, which revealed a proliferation of mononuclear cells in the dermis with prominent epidermotropism and positive expression of CD1a and langerin (CD207), supporting a diagnosis of Langerhans cell histiocytosis (LCH). LCH is an uncommon proliferative disorder of activated Langerhans cells, which generally presents in children. In adults, it is exceptionally infrequent. Associated malignancies and rare reports of AML developing in subsequent years after an initial presentation of LCH have been described. Here we present an unusual concurrent presentation of LCH and AML in an adult.

Cutaneous crospovidone reaction secondary to subcutaneous injection of buprenorphine.

Crospovidone is an insoluble pharmaceutical disintegrant that has been implicated in a rare foreign body reaction in injection drug users, classically associated with pulmonary angiothrombosis. We recently reported the first known cases of cutaneous crospovidone deposition. We herein report two additional cases with unique clinicopathologic manifestations, both in the setting of suspected injection drug abuse. Additionally, we provide a comprehensive overview of the distinct histomorphology and reproducible histochemistry of crospovidone.

Concordance Analysis of the 23-Gene Expression Signature (myPath Melanoma) With Fluorescence In Situ Hybridization Assay and Single Nucleotide Polymorphism Array in the Analysis of Challenging Melanocytic Lesions: Results From an Academic Medical Center.

BACKGROUND: Fluorescence in situ hybridization (FISH) and single nucleotide polymorphism (SNP) arrays are well-established molecular tests for the analysis of challenging melanocytic lesions. A 23-gene expression signature (GES), marketed as myPath Melanoma, is a recently introduced molecular test that categorizes melanocytic lesions as "benign," "malignant," and "indeterminate." There are few studies on the concordance between FISH, SNP, and GES in the analysis of melanocytic lesions. METHODS: A single-institution retrospective analysis of 61 contiguous cases of challenging melanocytic lesions with molecular analysis by 2 or more techniques. The primary objective was to determine the intertest agreement, which was calculated as percent agreement. A secondary objective was to determine the combined-test performance, that is, the frequency of obtaining a successful test (a test with an abnormal or normal, benign or malignant result) when 2 or more molecular tests were performed. RESULTS: Of the 61 cases, 58 cases were submitted for analysis using the GES assay, 44 cases were submitted for FISH analysis, and 21 cases were submitted for SNP array analysis. Percent agreement between GES and FISH array was 50.9% (18/34), which improved to 69.7% (18/23) when indeterminate/equivocal results were excluded. Similarly, percent agreement between GES and SNP array was 57.1% (8/14); this improved to 77.8% (7/9) when indeterminate/equivocal results were excluded. In 44% of cases submitted for GES and FISH and in 39% of cases submitted for GES and SNP, one test was successful and the other was not. CONCLUSION: For challenging melanocytic lesions, the choice of a molecular test is consequential as the GES assay correlated with FISH and SNP arrays approximately only half of the time. This improved when cases with indeterminate/equivocal results were excluded from the calculations. The combined-test analysis supports the utility of conducting more than one molecular test, as this increased the odds of obtaining a successful test.

Pachydermodactyly associated with extensive computer gaming: A report of three cases.

Pachydermodactyly is an uncommon, progressive, nontender thickening of the fingers with prominent involvement of the proximal interphalangeal joints. Pachydermodactyly mimics inflammatory arthritis but plain film radiography is normal in this condition. Pachydermodactyly has been previously described in workers performing manual labor. Mechanical stimulation has been identified as a predisposing factor in the majority of cases. We present three cases in adolescent males arising in association with excessive computer gaming.

Adenopathy and extensive skin patch overlying a plasmacytoma with unusual histologic findings in a patient with polyneuropathy, organomegaly, endocrinopathy, monoclonal protein and skin changes syndrome and Castleman disease.

A 56-year-old previously healthy man presented to the dermatology clinic with a 2-year history of an expanding, violaceous, infiltrated plaque on the right flank. Biopsy revealed a diffuse dermal vascular proliferation of bland, capillary-sized vessels admixed with conspicuous fibrohistiocytic cells including scattered multinucleated floret cells. Further workup revealed a monoclonal gammopathy, an osteolytic chest wall plasmacytoma underlying the plaque, and regional lymphadenopathy leading to a diagnosis of adenopathy and extensive skin patch overlying a plasmacytoma (AESOP). Biopsy of an enlarged lymph node revealed Castleman disease. The patient subsequently developed polyneuropathy and peripheral edema, which supported an additional diagnosis of polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes (POEMS) syndrome. Herein, we discuss the unique findings of our patient, the potential pathogenesis of AESOP, and the link between these three rare paraneoplastic entities along with review of the literature.

What's eating you? head lice (Pediculus humanus capitis).

The head louse (Pediculus humanus capitis) is a blood-sucking arthropod of the suborder Anoplura. Infestation continues in epidemic proportions in children of all socioeconomic groups. Although not implicated as a disease vector, infestation can lead to considerable distress, missed days of school, and secondary infections. Pyrethroids are recommended for treatment, but resistance is common. Newer agents, including benzyl alcohol and spinosad, have been developed to address this gap in care.

Atypical herpes zoster presentation in a healthy vaccinated pediatric patient.

We report the case of a 6-year-old girl with no notable medical history who presented to the dermatology clinic for evaluation of left leg pain with an overlying erythematous rash of 4 days' duration. Clinical examination revealed pink patches and plaques in a unilateral L5 distribution with an isolated pinpoint vesicle. Direct fluorescent antibody testing confirmed varicella-zoster virus (VZV) infection, establishing a diagnosis of herpes zoster (HZ). The patient previously had received the VZV vaccine in the left leg and arm and had no history of primary VZV infection. We summarize this case and discuss the epidemiology and clinical characteristics of HZ in vaccinated children.