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.

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. K E Y W O R D S adenopathy and extensive skin patch overlying a plasmacytoma, AESOP, Castleman disease, POEMS, polyneuropathy, organomegaly, endocrinopathy, monoclonal protein and skin changes

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.

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.

milii-related ICD has not been described before, it may induce keratoconjunctivitis causing burning pain, photophobia, lacrimation, and even decreased visual acuity. 4 Although one study testing sap or herb extracts from 60 different species in the Euphorbia genus on mice ears for the irritant effects concluded that 7 species including E. milii failed to produce irritation, the phorbol esters (one of the contents in croton oil), milliamines, euphorbol, and euphorbin in the sap were actually irritants to human skin. 1,5 Weber et al 3 suggested that Euphorbia sap-induced dermatitis is the result of a complex of cytopathogenic and proinflammatory effects. The direct pH-induced cytotoxicity of phorbol esters may induce corrosive effect leading to keratinocytes necrosis, whereas ingenol mebutate may cause recruitment of immune cells and augment the irritant reaction. 3 This report highlights the first case of ICD caused by E. milii with an atypical presentation as purpuric patches and provides an explanation of possible underlying pathophysiologic mechanisms. ZEBRAThe sap of E. milii is a potential source of ICD, and protective measures are necessary during handling these ornamental plants. ACKNOWLEDGMENTThe patient in this article has given written informed consent to publication of case details.