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The original article was published on March 15, 2020 and corrected on June 15, 2020. The revised version of the article corrects an Author's name. The changes appear in the revised online PDF copy of this article.

The original article was published on March 15, 2020 and corrected on June 15, 2020. The revised version of the article corrects an Author's name. The changes appear in the revised online PDF copy of this article.

Keratoacanthomas are rapidly growing neoplasms of squamous epithelium. Despite their benign nature, they are often difficult to distinguish from squamous cell carcinoma and require excision. In cases in which excision is not successful or not desired, intralesional treatments may be considered. However, limited research exists on individual therapeutic efficacy. We present a 68-year-old man who developed multiple eruptive keratoacanthomas around the wound edge of a previous keratoacanthoma excision. Considering previous excisional failure, intralesional 5-fluorouracil was used as a treatment modality. Injections every 3-4 weeks over a course of 12 weeks induced clinical keratoacanthoma clearance with excellent cosmetic results. This case showcases that weekly intralesional 5-fluorouracil injections, as was the standard mode of treatment in previous case reports, may not be necessary. This less frequent injection strategy is more convenient for the patient and may lead to fewer treatments and less medication necessary. Although a case-by-case basis is needed for any alternative approach to keratoacanthoma treatment, this report is useful for the practicing clinician in showing that 5-fluorouracil may be efficacious in these difficult-to-treat patients.

Pyoderma gangrenosum (PG) is a rare inflammatory cutaneous disease. Much of the underlying pathophysiology and etiology remain poorly understood, but PG is often associated with autoimmunity and chronic inflammatory and/or neoplastic diseases.1, 2 The disease can be extremely variable in presentation with either single or multiple lesions presenting on various parts of the body. PG is often difficult to diagnose because of variability of presentation, nonspecific laboratory findings, and indeterminate histology.3 Other conditions associated with cutaneous ulcerations must be considered in the differential diagnosis, such as infections, vasculitis, and malignancies. No official protocol exists for treatment of PG, but therapy usually involves immunosuppression in conjunction with wound care.1, 2, 4 We present a case of recalcitrant PG with widespread involvement that resolved with rituximab.

BackgroundKeratoacanthomas (KAs) are neoplasms of squamous epithelium which exhibit rapid growth and are often difficult to distinguish clinically from squamous cell carcinoma. Excision is the most common treatment, but in refractory cases or for KAs in cosmetically sensitive areas, nonoperative modalities may be better suited.ObjectiveTo compare efficacies of topical and intralesional therapies for the treatment of KAs.MethodsA systematic literature review was performed using Medline, Ovid, and Embase. Studies looking at the efficacy of topical or intralesional treatments for KAs were included. To compare efficacy, 2-tailed t-tests were performed, with P < .05 considered statistically significant.ResultsForty-one studies were identified across 5 modalities. Both topical and intralesional treatments had high KA eradication rates (92%-100%). Intralesional 5-fluorouracil led to faster KA healing times when compared to intralesional methotrexate (3.7 vs 4.6 weeks, P = .017). Similarly, topical 5-fluorouracil led to faster time to heal than topical imiquimod (3.8 vs 7.6 weeks with imiquimod, P < .0001).ConclusionFor nonoperative treatment of KAs, strong evidence currently exists for both topical and intralesional therapies. Decisions on which modality to use should be made on a case-by-case basis.

An 81-year-old man presented to the dermatology clinic with a painful lesion on his chest. The nodule would occasionally bleed and leak serous fluid for 10 years. Physical examination revealed an unspecified nodule with two superimposed nodules. A deep shave biopsy of the lesion was obtained and expressed a solid-cystic dermal neoplasm that was comprised of an admixture of cell types. Through the presenting clinical and histological features seen, a final diagnosis of nodular hidradenoma was made.

Patients with schizophrenia exhibit poor working memory (WM). Although several subcomponents of WM can be measured, evidence suggests the primary subcomponent affected in schizophrenia is span capacity (WMC). Indeed, the NIMH-funded MATRICS initiative recommended assaying the WMC when assessing the efficacy of a putative therapeutic for FDA approval. Although dopamine D1 receptor agonists improve delay-dependent memory in animals, evidence for improvements in WMC due to dopamine D1 receptor activation is limited. In contrast, the dopamine D2-family agonist bromocriptine improves WMC in humans. The radial arm maze (RAM) can be used to assess WMC, although complications due to ceiling effects or strategy confounds have limited its use. We describe a 12-arm RAM protocol designed to assess whether the dopamine D1-family agonist SKF 38393 (0, 1, 3, and 10 mg/kg) or bromocriptine (0, 1, 3, and 10 mg/kg) could improve WMC in C57BL/6N mice (n=12) in cross-over designs. WMC increased and strategy usage decreased with training. The dopamine D1 agonist SKF 38393 had no effect on WMC or long-term memory. Bromocriptine decreased WMC errors, without affecting long-term memory, consistent with human studies. These data confirm that WMC can be measured in mice and reveal drug effects that are consistent with reported effects in humans. Future research is warranted to identify the subtype of the D2-family of receptors responsible for the observed improvement in WMC. Finally, this RAM procedure may prove useful in developing animal models of deficient WMC to further assess putative treatments for the cognitive deficits in schizophrenia.