Mixed Versus Pure Variants of Desmoplastic Melanoma

BackgroundDesmoplastic melanoma (DM) is a subvariant of spindle cell melanoma, accounting for less than 4% of all cutaneous melanomas. It occurs later in life and is associated with chronic sun exposure. Desmoplastic melanoma prognosis is considered more favorable than other variants, with lower rates of metastasis and higher survival. Recently, DM has been further subclassified into pure and mixed, calling into question surgical management and patient outcomes as well as viability of current nationwide databases without this distinction.MethodsWe identified all patients with a histopathologic diagnosis of DM from the Cleveland Clinic electronic melanoma database (n = 58) from 1997 to 2013. Clinical and histopathologic data were collected. Comparison in clinical variables was performed between patients who had pure (n = 15) and mixed (n = 43) variants of DM.ResultsThere were no differences in age, sex, location of lesion, Breslow depth, ulceration, or regression. Patients with mixed DM were more likely to have lymphovascular invasion (P = 0.03) compared with pure DM. There was no difference in performance of sentinel lymph node biopsy (P = 0.25) or sentinel lymph node positivity (P = 0.31) between the 2 groups. Recurrence was present in 13.3% of pure and 30.2% of mixed patients. Overall, Kaplan-Meier 3-year survival was 75% for pure and 80% for mixed DM (P = 0.53).ConclusionsPure and mixed DMs seem to have similar clinical characteristics and outcomes. This indicates that analysis of national datasets without this subclassification remains viable

σ1 Receptor Modulation of G-Protein-Coupled Receptor Signaling: Potentiation of Opioid Transduction Independent from Receptor Binding

σ Ligands modulate opioid actions in vivo, with agonists diminishing morphine analgesia and antagonists enhancing the response. Using human BE(2)-C neuroblastoma cells that natively express opioid receptors and human embryonic kidney (HEK) cells transfected with a cloned μ opioid receptor, we now demonstrate a similar modulation of opioid function, as assessed by guanosine 5′-O-(3-[35S]thio)triphosphate ([35S]GTPγS) binding, by σ1 receptors. σ Ligands do not compete opioid receptor binding. Administered alone, neither σ agonists nor antagonists significantly stimulated [35S]GTPγS binding. Yet σ receptor selective antagonists, but not agonists, shifted the EC50 of opioid-induced stimulation of [35S]GTPγS binding by 3- to 10-fold to the left. This enhanced potency was seen without a change in the efficacy of the opioid, as assessed by the maximal stimulation of [35S]GTPγS binding. σ1 Receptors physically associate with μ opioid receptors, as shown by coimmunoprecipitation studies in transfected HEK cells, implying a direct interaction between the proteins. Thus, σ receptors modulate opioid transduction without influencing opioid receptor binding. RNA interference knockdown of σ1 in BE(2)-C cells also potentiated μ opioid-induced stimulation of [35S]GTPγS binding. These modulatory actions are not limited to μ and δ opioid receptors. In mouse brain membrane preparations, σ1-selective antagonists also potentiated both opioid receptor and muscarinic acetylcholine receptor-mediated stimulation of [35S]GTPγS binding, suggesting a broader role for σ receptors in modulating G-protein-coupled receptor signaling

Accuracy in melanoma detection: a 10-year multicenter survey

Early excision is the only strategy to reduce melanoma mortality, but unnecessary excision of benign lesions increases morbidity and healthcare costs