Keratoacanthoma formation after skin grafting: A brief report and pathophysiological hypothesis.

Keratoacanthoma formation after skin grafting is rare. We report the third case in the literature of multiple keratoacanthomas developed at both split-thickness skin graft donor and recipient sites. We provide possible explanations for this poorly understood phenomenon and highlight its implications on treatment options.

Keratoacanthoma: a distinct entity?

Keratoacanthoma (KA) are common but exceptional benign tumors, often appearing on sun-exposed areas of light skinned people and showing spontaneous resolution. The goal of this study was to review existing literature, to point out the etiological complexity of KA biology and to answer the controversial debate if or not KA is a distinct entity or a variant of squamous cell carcinoma (SCC). Relying on recent results, we highlight that KA is an individual lesion with a unique molecular signature caused by alterations in the TGFß signalling pathway. These recent findings will help to understand the nature of KA and to develop new reliable diagnostic tools, simplifying the discrimination of the histologically similar KA and SCC.

Neglect leads to extremes: maggots and malignancy in a case of discoid lupus erythematosus.

Discoid lupus erythematosus (DLE) is a chronic form of cutaneous lupus erythematosus that runs an indolent course. The rare complications of DLE include scarring, mutilation, non-healing ulceration, cicatricial alopecia and malignancy. DLE progresses to systemic lupus erythematosus (SLE) in around 5% of localized cases and 22% of generalized cases. We report a case of DLE, presenting with a six-month history of ulcerated fungating plaques and small crusted nodules superimposed on DLE plaques over both the forearms. Two weeks prior to the presentation, maggots were also noticed on these plaques. Skin biopsies from these lesions were suggestive of squamous cell carcinoma (SCC) and keratoacanthoma. A wide surgical excision of the tumor followed by partial split-thickness skin grafting was performed with complete healing of the lesions. No recurrence has been noted 18 months from follow-up.

Keratoacanthoma (KA): An update and review.

Keratoacanthoma (KA) is a common but underreported tumor of the skin. Two striking features of KA are its clinical behavior with spontaneous regression after rapid growth and its nosological position on the border between benignity and malignancy. We review current knowledge on the clinical, histopathological, and dermoscopic features of KA to ensure a proper diagnosis and describe its variants, including different types of multiple KAs. We highlight current concepts of KA ethiopathogenesis with special emphasis on the genetic background of multiple familial KA, the role of Wnt signaling pathway, and induction of KA by BRAF inhibitors and procedures of esthetic dermatology. Finally, treatment strategies are presented with surgical excision as a first option, followed by other modalities, including intralesional chemotherapy, topical and systemic agents, lasers, cryotherapy, and photodynamic therapy.

Multiple Eruptive Keratoacanthomas Secondary to Nivolumab Immunotherapy.

Immune checkpoint inhibitors are increasingly being utilized for the treatment of advanced neoplastic disease and have been associated with wide-ranging cutaneous adverse effects. Though exceedingly rare, eruptive keratoacanthomas have been associated with the use of immune checkpoint inhibitors such as pembrolizumab and nivolumab, whose molecular target is the programmed cell death protein 1. Herein, we detail a case of numerous eruptive keratoacanthomas arising in a patient one month after initiation of nivolumab for recurrent metastatic oropharyngeal squamous cell carcinoma. Treatment with multiple rounds of intralesional corticosteroids and a several-month course of oral acitretin resulted in partial improvement. Subsequent treatment with intralesional 5-fluorouracil demonstrated near-complete resolution of the keratoacanthomas without discontinuation of nivolumab. Although eruptive keratoacanthomas secondary to immune checkpoint inhibitors are exceptionally rare, physicians should be aware of this cutaneous adverse effect as their use becomes more widespread.

Spontaneous resolution of eruptive papules following ablative laser resurfacing-Case report and review of laser-associated eruptive keratoacanthomas.

BACKGROUND: Keratoacanthomas (KAs) following laser treatment are a rare, but well-described entity. AIM: Herein, we describe a case of eruptive keratoacanthoma (KA) following laser resurfacing treatment and aim to better characterize laser-associated KAs. METHODS: A literature search was performed on PubMed reviewing laser-associated KAs including various characteristics: epidemiology, history of skin cancer, location, and number, type of laser, as well as the management and outcome. RESULTS: Fractional ablative was the most common type of laser triggering KAs, and most cases presented within the first month following treatment. The majority of cases of laser-induced KA had a prior history of a malignant or premalignant skin neoplasm. Laser-induced KAs were treated using modalities similar to KAs arising in other contexts. CONCLUSION: Clinicians need to be knowledgeable and prepared to understand, and manage complications following laser treatments, as rare as they may be, including KAs.

A pathergic response to fractional CO2.

Pathergy is a nonspecific response to stimuli seen in a multitude of disease states. We present what we feel is a unique variant of this phenomenon, a case of multiple keratoacanthomas developing following treatment with Fractional CO2. This state of acute tumor emergence, which is similar to an isomorphic response, is believed to be related to changes in both the inflammatory and immune response. It is imperative that one keeps this process in their differential when evaluating a patient that has not only a potential predisposing disease, but also a history of traumatic exposure.

Analysis of the 3'UTR of the prostaglandin synthetase-2 (PTGS-2/COX-2) gene in non-melanoma skin cancer after organ transplantation.

To define the potential involvement of polymorphisms in the 3'untranslated region (3'UTR) of the prostaglandin synthetase-2 (PTGS-2) gene to non-melanoma skin cancer (NMSC) predisposition after transplantation, we screened for genetic variant, relevant parts of this region. It contains binding sites for trans-acting factors, an alternative polyadenylation site and putative target sequences for miRNAs. Variant +8473T>C did not appear to play a functional role in the regulation of gene expression in human keratinocyte-transfected cells. In addition to the well-known +8473T>C, we identified four polymorphisms: +8293G>C, +10259T>G, +10267G>A and +10335G>A. No allele frequency differences were observed between cases and controls neither for +8473T>C nor for any of the identified polymorphisms, suggesting that polymorphisms in the 3'UTR of the PTGS2 gene are rare and unlikely to represent risk factor for NMSC after transplantation.

Tattoo-associated keratoacanthomas: a series of 8 patients with 11 keratoacanthomas.

BACKGROUND: Keratoacanthoma is interpreted by many dermatopathologists in the United States as a form of squamous cell carcinoma that can spontaneously involute. Rare examples arising in tattoos have been reported in the literature. MATERIALS AND METHODS: We retrospectively reviewed all cases from our institution received between 2000 and 2008 for any that reported a tumor within a tattoo. RESULTS: We identified eight patients with keratoacanthomas that arose within tattoos. One of the patients had four separate keratoacanthomas arising within two separate tattoos. Red tattoo ink was associated with 82% of the keratoacanthomas. CONCLUSIONS: Keratoacanthomas are more common than previously reported in tattoos and are easily misinterpreted. The association with red tattoo ink suggests a form of hypersensitivity-associated with adnexal hyperplasia. Tattoo-associated squamous tumors with innocuous nuclei, infundibulocystic structures, adnexal hyperplasia, and signs of regression should be reported as keratoacanthomas rather than as variants of squamous cell carcinoma.

Keratoacanthomas: overview and comparison between Houston and minneapolis experiences.

Keratoacanthomas represent approximately 1% of skin malignancies treated in a Mohs practice in Houston, TX. The authors compared the age of onset, sex, location and month of prevalence of keratoacanthomas between Houston, TX and Minneapolis, MN. An earlier age of presentation was observed in men in Houston (65.9 years) versus in women (71.3 years) or in men and women in Minneapolis (71 years). There was a predominance of facial tumors in Texas males compared to females and tumors seen in Minneapolis. The tumors occurred more frequently during the winter months in Houston, TX versus June, November and December in Minneapolis, MN.