Keratoacanthoma as a postoperative complication of skin cancer excision

Advances in cutaneous squamous cell carcinoma

Human malignancies arise predominantly in tissues of epithelial origin, where the stepwise transformation from healthy epithelium to premalignant dysplasia to invasive neoplasia involves sequential dysregulation of biological networks that govern essential functions of epithelial homeostasis. Cutaneous squamous cell carcinoma (cSCC) is a prototype epithelial malignancy, often with a high tumour mutational burden. A plethora of risk genes, dominated by UV-induced sun damage, drive disease progression in conjunction with stromal interactions and local immunomodulation, enabling continuous tumour growth. Recent studies have identified subpopulations of SCC cells that specifically interact with the tumour microenvironment. These advances, along with increased knowledge of the impact of germline genetics and somatic mutations on cSCC development, have led to a greater appreciation of the complexity of skin cancer pathogenesis and have enabled progress in neoadjuvant immunotherapy, which has improved pathological complete response rates. Although measures for the prevention and therapeutic management of cSCC are associated with clinical benefit, the prognosis remains poor for advanced disease. Elucidating how the genetic mechanisms that drive cSCC interact with the tumour microenvironment is a current focus in efforts to understand, prevent and treat cSCC.

Eruptive Non-melanoma Skin Cancers/Squamous Atypia Following Skin Surgery. Report of Two New Cases, Concise Review of the Literature With Special Emphasis on Treatment Options

INTRODUCTION

Eruptive cutaneous squamous cell carcinomas (ESCC), eruptive squamous atypia (ESA) and eruptive keratoacanthomas (EKA) are different terms used to describe the occurrence of multiple cutaneous squamous neoplasms after skin surgery, laser treatment, traumas, such as tattoos, and local or systemic medical treatments. ESCC have been reported to arise at the sites of skin surgery, including the area affected by the primary tumor and split thickness skin graft (STSG) donor and recipient sites.

OBJECTIVES

The aim of this study is to report 2 additional cases of ESCC after skin surgery and make a critical revision of the literature, analyzing the clinical, histological features and outcomes of ESCC after cutaneous surgery.

METHODS

Up to August 2021, according to our systematic review of the literature, we have collected 19 published articles and a total of 34 patients, including our 2 cases.

RESULTS

The results of this review highlight five red flags that clinicians should consider: (i) lower and upper limbs represent the cutaneous site with the highest risk, representing 83,78% of the cases in the literature; (ii) the median time to onset of ESCC is approximately 6 weeks; (iii) primary cutaneous squamous cell carcinomas were completely excised with free margins on histologic examination in the totality of the cases of the literature, and therefore ESCC should not be considered recurrences; (iv) any surgical technique involves a risk to promote ESCC; (v) treatment of ESCC includes medical treatment, surgery or combined surgical and medical treatment.

CONCLUSIONS

This review highlights 5 red flags which could support clinicians in the diagnosis and management of ESCC after skin surgery.

A clinical and biological review of keratoacanthoma

Keratoacanthoma (KA) is a common skin tumour that remains controversial regarding classification, epidemiology, diagnosis, prognosis and management. Classically, a KA manifests as a rapidly growing, well-differentiated, squamoid lesion with a predilection for sun-exposed sites in elderly people and a tendency to spontaneously regress. Historically, KAs have been considered a variant of cutaneous squamous cell carcinoma (cSCC) and are often reported as KA-type cSCC. However, the penchant for regression has led many to categorize KAs as biologically benign tumours with distinct pathophysiological mechanisms from malignant cSCC. The clinical and histopathological similarities between KA and cSCC, particularly the well-differentiated variant of cSCC, have made definitive differentiation difficult or impossible in many cases. The ambiguity between entities has led to the general recommendation for surgical excision of KAs to ensure a potentially malignant cSCC is not left untreated. This current standard creates unnecessary surgical morbidity and financial strain for patients, especially the at-risk elderly population. There have been no reports of death from a definitive KA to date, while cSCC has an approximate mortality rate of 1·5%. Reliably distinguishing cSCC from KA would shift management strategies for KAs towards less-invasive treatment modalities, prevent unnecessary surgical morbidity, and likely reduce associated healthcare costs. Herein, we review the pathophysiology and clinical characteristics of KA, and conclude on the balance of current evidence that KA is a benign lesion and distinct from cSCC.

Incisional squamous cell carcinoma after total knee arthroplasty

With the rising number of total knee arthroplasties being performed annually, the number of complications associated with this procedure will also continue to rise. The most common reasons for revision include infection, instability, and aseptic loosening. Fortunately, wound complications are rare, and in this case report, we describe the development of a well-differentiated squamous cell carcinoma, keratoacanthomatous type, within the surgical incision of a total knee arthroplasty several months after the index procedure.

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

BACKGROUND

Eruptive squamous atypia (ESA), which is an idiopathic, sometimes koebnerizing, proliferation of atypical but well-differentiated keratinocytes (also termed eruptive keratoacanthoma), is often misdiagnosed as cancer and managed by excisional surgery, provoking further koebnerization. A clear definition of this phenomenon and treatment outcome data are lacking.

OBJECTIVE

To define ESA and evaluate efficacy of intralesional (IL) 5-fluorouracil (5-FU) treatment.

METHODS

A retrospective cohort study examined patients with ESA that arose spontaneously or within a recent surgical scar and was treated with IL 5-FU at a tertiary academic center between January 2008 and December 2016. Complete clearance, partial clearance, and number of surgical excisions performed were tabulated.

RESULTS

Of 30 patients with 136 ESA lesions, 20 (67%) had resolution of ESA with IL 5-FU monotherapy. In all, 10 patients (33%) required additional therapy (topical 5-FU, steroids, cryotherapy, or acitretin). No IL 5-FU-treated ESA lesions required surgical excision. The number of excisional procedures decreased significantly (P = .006), with 27 patients (90%) needing fewer excisions 12 months after versus 12 months before initiation of IL 5-FU therapy. Dyspigmentation was the only adverse event.

LIMITATIONS

Limitations include retrospective analysis and use of data from a single institution.

CONCLUSION

With close clinical monitoring, IL 5-FU can be used to successfully treat ESA.

Clear-Cell Atypical Fibroxanthoma: A Combined Immunohistochemistry Analysis

Atypical fibroxanthoma is considered to be a low-grade sarcoma, characterized by a proliferation of bizarre spindled cells. A case of a rare variant of this tumor, a clear-cell atypical fibroxanthoma, presenting with rapid growth on a 63-year-old female, is reported. The differential diagnosis of a clear cell proliferation and a review of the immunohistochemistry markers used in the diagnosis of atypical fibroxanthoma are discussed. In particular, the usefulness of markers such as CD10, procollagen 1, CD68, CD163, CD99, and S100A6, and the importance of negative markers such as S100, cytokeratin, and desmin are emphasized. Furthermore, the development of a keratoacanthoma at the site of previous Mohs surgery is recounted.

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.

Squamous cell carcinoma of the skin: epidemiology, classification, management, and novel trends

Squamous cell carcinoma (SCC) is the second most common non-melanoma skin cancer. It originates from epidermal keratinocytes or adnexal structures (such as eccrine glands or pilosebaceous units). We describe the salient features of cutaneous SCC. We also review novel classification schemes proposed during the last decade which attempt to stratify SCC lesions based on prognosis. Biopsy leads to definitive diagnosis. Treatment includes surgical excision; Mohs micrographic surgery produces excellent cure rates and spares the maximal amount of tissue. Other modalities include electrodessication and curettage, cryosurgery, radiotherapy, topical medications, photodynamic therapy, and systemic therapy. Management and follow-up depend on the risk stratification of individual lesions.

Perforating granulomatous dermatitis reaction to exogenous tattoo pigment: a case report and review of the literature

: The majority of cutaneous hypersensitivity reactions to exogenous tattoo pigments can be histologically classified as lichenoid or granulomatous. The etiology is still uncertain but is generally accepted to be a delayed-type hypersensitivity reaction to either the pigment itself or its carrier solution. In this report, we review the literature concerning adverse reactions to tattoos. In addition, we describe the second case of a localized granulomatous dermatitis to the red dye within a tattoo that histologically resembled granuloma annulare. This is the first reported example of a perforating granuloma annulare-like reaction.

AAD/ACMS/ASDSA/ASMS 2012 appropriate use criteria for Mohs micrographic surgery: a report of the American Academy of Dermatology, American College of Mohs Surgery, American Society for Dermatologic Surgery Association, and the American Society for Mohs Surgery

The appropriate use criteria process synthesizes evidence-based medicine, clinical practice experience, and expert judgment. The American Academy of Dermatology in collaboration with the American College of Mohs Surgery, the American Society for Dermatologic Surgery Association, and the American Society for Mohs Surgery has developed appropriate use criteria for 270 scenarios for which Mohs micrographic surgery (MMS) is frequently considered based on tumor and patient characteristics. This document reflects the rating of appropriateness of MMS for each of these clinical scenarios by a ratings panel in a process based on the appropriateness method developed by the RAND Corp (Santa Monica, CA)/University of California-Los Angeles (RAND/UCLA). At the conclusion of the rating process, consensus was reached for all 270 (100%) scenarios by the Ratings Panel, with 200 (74.07%) deemed as appropriate, 24 (8.89%) as uncertain, and 46 (17.04%) as inappropriate. For the 69 basal cell carcinoma scenarios, 53 were deemed appropriate, 6 uncertain, and 10 inappropriate. For the 143 squamous cell carcinoma scenarios, 102 were deemed appropriate, 7 uncertain, and 34 inappropriate. For the 12 lentigo maligna and melanoma in situ scenarios, 10 were deemed appropriate, 2 uncertain, and 0 inappropriate. For the 46 rare cutaneous malignancies scenarios, 35 were deemed appropriate, 9 uncertain, and 2 inappropriate. These appropriate use criteria have the potential to impact health care delivery, reimbursement policy, and physician decision making on patient selection for MMS, and aim to optimize the use of MMS for scenarios in which the expected clinical benefit is anticipated to be the greatest. In addition, recognition of those scenarios rated as uncertain facilitates an understanding of areas that would benefit from further research. Each clinical scenario identified in this document is crafted for the average patient and not the exception. Thus, the ultimate decision regarding the appropriateness of MMS should be determined by the expertise and clinical experience of the physician.

Skin cancers of the hand and upper extremity

Skin cancers represent the most common primary malignancies of the hand. They typically present as painless lesions on areas of high sun exposure, such as the dorsum of the hand and upper extremity. The most common malignancy is squamous cell carcinoma, followed by basal cell carcinoma and melanoma. The key to successful treatment is early and accurate diagnosis and treatment. Unlike open biopsies, which are indicated for deep soft tissue and bone lesions, biopsies for skin cancer can be performed under local anesthesia in the office setting in the form of shave or punch biopsies. A number of nonsurgical treatment options are available for treatment. However, when surgical excision is indicated, appropriate margin resections are dictated by the grade and stage of the malignancy.

Needs assessment for Mohs micrographic surgery

Mohs micrographic surgery (MMS) is a unique technique that can offer the highest cure rates and maximum tissue conservation in the management of specific primary and recurrent skin cancers. However, there are many areas of controversy that surround MMS, including appropriate indications for its use, technical quandaries, and outcomes. Recent efforts in these areas need to be assessed to identify research gaps in MMS to help fuel further work. The usefulness of MMS and its methods for delivery need more stringent, evidence-based, rigorous study.

Eruptive squamous cell carcinomas, keratoacanthoma type, arising in a multicolor tattoo

Permanent tattoos are formed through the injection of ink solids through the epidermis into the dermis and can cause multiple adverse reactions. We report a 38-year-old man who presented to our Dermatologic Surgery Unit with a diagnosis of a superficially invasive squamous cell carcinoma (SCC), keratoacanthoma (KA) type, of the left forearm in a 1-month-old tattoo. Since his initial biopsy, he developed four more similar lesions on his left forearm within his tattoo. On physical examination, the patient had a large, multicolor tattoo on his left forearm, a well-healed surgical biopsy site and four erythematous hyperkeratotic papules within differently pigmented areas of the patient's tattoo. Histopathological examination showed KA and tattoo pigment. Based on the eruptive nature of these lesions, their clinical presentation and the histopathological changes, we report this as the first case of eruptive KA arising in a multicolor tattoo.

Multiple keratoacanthomas in a young woman: report of a case emphasizing medical management and a review of the spectrum of multiple keratoacanthomas

A 27-year-old white woman was referred for consultation with regard to the presence of extensive multiple keratotic lesions. She began to develop these lesions at the age of 9 years, with healing of the lesions resulting in scar formation. A biopsy was performed at the age of 16 years, but the patient was unsure of the results. Since then, she had not had any treatment or biopsies, and stated that she had not suffered from any health problems during the intervening period. She was most concerned about the tumors on her heels and soles, which caused difficulty with ambulation. The family history was negative for skin diseases, including melanoma, nonmelanoma skin cancer, psoriasis, and eczema, and positive for Type II diabetes mellitus. A relative reported that the patient's grandfather had similar lesions, but the patient's parents and siblings were healthy. She was married and had one child, a 9-year-old daughter. Her child had no skin lesions. The patient's only medication was Ortho-Tricyclene birth control pills. She had no known drug allergies. Physical examination revealed the presence of multiple lesions on her body (Fig. 1). Her left superior helix contained a well-demarcated, dome-shaped nodule with a rolled, mildly erythematous border with a central hyperkeratotic plug. A similar lesion was present in the scaphoid fossa of the left ear and smaller lesions were scattered on her face. Numerous lesions were present on the arms and legs bilaterally, with the majority of lesions being located on the anterior lower legs. There were also lesions present on the palms and soles. The lesions ranged in size from 5 mm to 3 cm, the largest being a verrucous exophytic nodule on the anterior aspect of her left leg. Overall, there appeared to be two distinct types of lesion. One type appeared round, oval, and symmetric with a central keratotic plug, similar to that on the ear. The other type was larger, more exophytic, and verrucous, including the lesions on the volar surfaces. Also present were numerous, irregularly shaped atrophic scars where previous lesions had healed spontaneously. There were no oral lesions or lesions on her fingernails or toenails, and her teeth and hair were normal. A biopsy was obtained from an early lesion on the right dorsal forearm. Histology revealed an exo-/endophytic growth having a central crater containing keratinous material (Fig. 2). The crater was surrounded by markedly hyperplastic squamous epithelium with large squamous epithelial cells having abundant glassy cytoplasm. Some cells were dyskeratotic. Within the dermis was a dense, chiefly mononuclear inflammatory infiltrate. A buttress of epidermis surrounded the crater. The clinical and pathologic data were consistent with keratoacanthomas. Initial laboratory screenings revealed elevated triglycerides and total cholesterol, 537 mg/dL (normal, < 150 mg/dL) and 225 mg/dL (normal, < 200 mg/dL), respectively, with all other laboratory results within normal limits. In anticipation of starting oral retinoid therapy for her multiple keratoacanthomas, she was referred to her primary care physician for control of hyperlipidemia. After her lipids had been controlled, she was placed on isotretinoin (Accutane) 40 mg/day. There was some interval improvement with regression of some lesions leaving atrophic scars. She was also started on topical application of tazarotene (Tazorac) for all nonresolving lesions. Possible side-effects from the isotretinoin occurred, including dry mouth and eyes. After 8 months of isotretinoin, the patient was switched to acitretin (Soriatane) 25 mg to determine whether it might have a more beneficial effect on the resistant lesions. Many of the larger lesions regressed leaving atrophic scars. The dose of acitretin was subsequently increased to 35 mg because the lesions on her heel and the ball of her foot persisted. Almost all of the lesions resolved, except those on her feet, which are slowly regressing. Currently, the patient is on a regimen of acitretin 25 mg once a day with tazarotene 0.1% gel applied directly to the few residual keratoacanthomas on her feet, which are slowly improving.

Transformation-specific matrix metalloproteinases, MMP-7 and MMP-13, are present in epithelial cells of keratoacanthomas

Keratoacanthomas are rapidly growing hyperproliferative skin tumors that may clinically or histologically be difficult to distinguish from well-differentiated squamous cell cancers (SCCs). UV light, trauma, and immune suppression represent their etiological factors. As matrix metalloproteinases (MMPs) are implicated at all stages of tumorigenesis, we investigated the expression profile of several cancer-related MMPs to find markers that would differentiate keratoacanthomas from SCCs and shed light to the pathobiology of keratoacanthoma. Samples from 31 keratoacanthomas and 15 grade I SCCs were studied using immunohistochemistry for MMP-2, -7, -8, -9, -10, -13, and -19 and p16 and laminin-5gamma2 chain. In situ hybridization for MMP-7, -10, and -13 was performed in a subset of tumors. Keratinocytes with atypia, presence of neovascularization, and composition of the inflammatory infiltrate were graded from hematoxylin-eosin stainings. MMP-7 was present in the epithelium of 4/31 keratoacanthomas and 9/15 SCCs, MMP-8 in 3/30 keratoacanthomas and 0/15 SCCs, but MMP-13 in 16/31 keratoacanthomas and 10/15 SCCs, and MMP-10 in 28/31 keratoacanthomas and all cancers. MMP-9 was detected in the epithelium in 5/31 keratoacanthomas and 8/15 SCCs, whereas MMP-2 was only present in fibroblasts in both tumors. MMP-19 was upregulated in proliferating epithelium of keratoacanthomas as was p16. Cytoplasmic laminin-5gamma2 was particularly abundant in keratinocytes at the pushing border of MMP-13-positive keratoacanthomas. We conclude that although some MMPs (MMP-10 and -13) are abundantly expressed in keratoacanthomas, the presence of MMP-7 and -9 in their epithelial pushing border is rare and should raise suspicion of SCC. Further, the loss of MMP-19 and p16 could aid in making the differential diagnosis between well-differentiated SCC and keratoacanthoma. Frequent expression of the transformation-specific MMP-13 in keratoacanthomas suggests that they are not benign tumors but incomplete SCCs.

Intralesional methotrexate for keratoacanthoma of the nose

A 56-year-old woman developed a nodule on her nose. A shave biopsy of the enlarging lesion was performed after 2 weeks and showed a keratoacanthoma. During the subsequent 4 weeks, the lesion continued to grow rapidly, and she was referred for excision of the lesion using the Mohs microscopically controlled technique. A tender 10x12 mm (120 mm2) erythematous nodule with a keratin-filled central umbilication was present on her left nasal ala (Figure 1). Treatment options were discussed. The left nasal ala was locally anesthetized with 1% lidocaine with 1:100,000 epinephrine and the keratoacanthoma was circumferentially infiltrated with 10 mg of methotrexate (0.8 mL of 12.5 mg/mL methotrexate) using a 30-gauge needle. The total amount of methotrexate injected was divided among several injection sites: the peripheral shoulder of the lesion (such that there was blanching of the entire rim) and under the center of the lesion at a depth clinically judged to be the deepest area of involvement. Within the next 7 days, the tumor began to decrease in size and ulcerate centrally. Examination 2 weeks after the initial injection showed a 71% reduction in the area of the tumor, which now measured 35 mm2 (7.0x5.0 mm). The tumor was injected in a similar manner as before with 5 mg of methotrexate. After another 2 weeks, the tumor had continued to shrink. It was flat without nodularity and measured 12 mm2 (4.0x3.0 mm); the tumor area was 66% less than 2 weeks earlier and 90% less than its original size. The residual tumor was again injected with 4.5 mg of methotrexate. There was complete clinical involution of the tumor when the patient returned for evaluation 6 weeks after her initial injection of methotrexate (Figure 2). A biopsy of the lesional area to confirm histologic resolution of the keratoacanthoma was not performed since there was no visible residual tumor. Periodic follow-up examination has been performed and there has been no subsequent recurrence of the keratoacanthoma.