Primary mucinous carcinoma of the skin: the Mayo Clinic experience over the past 2 decades.

BACKGROUND: Primary mucinous carcinoma of the skin (PMCS) is a rare adnexal eccrine sweat gland neoplasm, often mistaken for metastasis from extracutaneous sites or misdiagnosed. Primary mucinous carcinoma of the skin is a slow-growing tumor with a high recurrence rate after conventional excision. OBJECTIVE: To describe clinicopathologic features, rate of recurrence, and metastasis and to review relevant literature. MATERIALS AND METHODS: The authors identified patients with PMCS treated from January 1992 through December 2012 at Mayo Clinic. The authors retrospectively reviewed medical records and histology slides. Relevant publications were identified through Ovid MEDLINE and PubMed. RESULTS: Six patients with PMCS were identified (1 male). The average age at diagnosis was 63 years. Tumor size ranged from 0.5 to 2.0 cm, and all were confined within the dermis. No evidence of metastatic mucinous adenocarcinoma was documented at the time of diagnosis. Five patients underwent Mohs micrographic surgery, and 1 was treated with wide local excision. There were no episodes of recurrence or metastases after a median follow-up of 20 months (range, 0.5-207 months). CONCLUSION: Mohs micrographic surgery may offer reduced recurrence rates and better outcomes in PMCS. Further studies with longer follow-up and bigger cohorts of patients with PMCS are warranted.

OnabotulinumtoxinA therapy for compensatory hyperhidrosis.

BACKGROUND: Compensatory hyperhidrosis due to the treatment for focal primary hyperhidrosis can be devastating and life-altering. OBJECTIVE: The purpose of this paper is to discuss use of the iodine starch test and dilute botulinum toxin to decrease compensatory hyperhidrosis over large surface areas. METHODS: A large area of the trunk affected by compensatory hyperhidrosis was treated with dilute botulinum toxin therapy using a starch iodine test for localization. RESULTS: The patient had exceptional results with his compensatory truncal sweating returning to normal and remaining stable for multiple months. CONCLUSION: Treating compensatory hyperhidrosis of large surface areas with dilute botulinum toxin therapy is effective and safe.

Metal-free ALS variants of dimeric human Cu,Zn-superoxide dismutase have enhanced populations of monomeric species.

Amino acid replacements at dozens of positions in the dimeric protein human, Cu,Zn superoxide dismutase (SOD1) can cause amyotrophic lateral sclerosis (ALS). Although it has long been hypothesized that these mutations might enhance the populations of marginally-stable aggregation-prone species responsible for cellular toxicity, there has been little quantitative evidence to support this notion. Perturbations of the folding free energy landscapes of metal-free versions of five ALS-inducing variants, A4V, L38V, G93A, L106V and S134N SOD1, were determined with a global analysis of kinetic and thermodynamic folding data for dimeric and stable monomeric versions of these variants. Utilizing this global analysis approach, the perturbations on the global stability in response to mutation can be partitioned between the monomer folding and association steps, and the effects of mutation on the populations of the folded and unfolded monomeric states can be determined. The 2- to 10-fold increase in the population of the folded monomeric state for A4V, L38V and L106V and the 80- to 480-fold increase in the population of the unfolded monomeric states for all but S134N would dramatically increase their propensity for aggregation through high-order nucleation reactions. The wild-type-like populations of these states for the metal-binding region S134N variant suggest that even wild-type SOD1 may also be prone to aggregation in the absence of metals.