Eruptive squamous atypia (also known as eruptive keratoacanthoma): Definition of the disease entity and successful management via intralesional 5-fluorouracil

Comment on “Intralesional methotrexate for keratoacanthomas: A retrospective cohort study”

“…Indeed, the high effectiveness rate observed in these 2 studies supports the investigation by Que et al, 3 who considered KA and eruptive squamous atypia as different entities and remarked on the importance of careful management.…”

“…Recently, the term eruptive squamous atypia (ESA) was introduced by the Brigham and Women's Hospital research group, leading to the ability to distinguish between KA and those synchronous multiple hyperkeratotic lesions developing on the extremities, historically known as eruptive keratoacanthomas. 3 According to this publication, we believe that many of the tumors treated by Smith et al 1 could meet these criteria and may have been misdiagnosed. We consider that this likely situation, as well as the lack of systematic histopathologic evaluation of the tumors, could have notoriously overestimated the real efficacy of il-MTX in KA.…”

Keratoacanthoma, committed stem cells and neoplastic aberrant infundibulogenesis integral to formulating a conceptual model for an infundibulocystic pathway to squamous cell carcinoma

“…Trauma has been linked to the emergence of KAs in a range of clinical scenarios 20‐22 . This event may occur in the wake of surgery including skin grafts (Figure 3A, B) 23 radiotherapy, cryotherapy, burns and as a complication of chronic prurigo.…”

“…18,19 5 | KA AND THE WOUND HEALING PATHWAY Trauma has been linked to the emergence of KAs in a range of clinical scenarios. [20][21][22] This event may occur in the wake of surgery including skin grafts ( Figure 3A, B) 23 SCCs that can be eruptive. The relationship of stem cells, carcinogenesis, and the wound pathway is complex.…”

Intralesional methotrexate for keratoacanthomas: A retrospective cohort study

“…1,2 Treatment is often surgical; however, alternate options are often sought. Successful use of intralesional (IL) agents such as methotrexate (MTX) (up to 88% resolution) 3 or 5-fluorouracil (up to 67% resolution) 4 has been reported for KAs, although in small cohorts. This institutional review boardeapproved study reports additional data on the efficacy of IL MTX for KAs.…”