Traumatic keratoacanthoma arising in a 15-year-old boy following a motor vehicle accident

Keratoacanthomas appear most commonly in sun-damaged skin in middle-aged and elderly people. We present a 15-year-old boy who developed a rapidly growing nodule within a hypertrophic scar that was the result of trauma suffered in a roll-over motor vehicle accident 8 months prior to presentation. Histologic analysis of a biopsy specimen of the nodule confirmed the presence of squamous cell carcinoma, keratoacanthoma type. The development of keratoacanthoma has been associated with sun exposure, chemical carcinogens, radiation therapy, genetic factors, and various forms of antecedent trauma, including surgery or grafting, thermal burns, laser resurfacing, and vaccination. This report describes the youngest patient with traumatically-induced keratoacanthoma, and is the first instance of this entity arising in a friction burn.     

Intraläsionale Methotrexat-Injektion

A 53 year old female patient developed a keratoacanthoma, present on the left side of her nose for two months. After repeated unsuccessful trials with cryotherapy, she was treated with intralesional injection of methotrexate performed twice with a weekly internal. This led to complete resolution within 5 weeks. Although controlled studies on the effect of methotrexate in keratoacanthoma are not available, the rapid regression and the good cosmetic result suggest that this therapy may play a beneficial role in treating these lesions especially in problem locations.     

Multiple keratoacanthoma-like neurodermatitis nodularis

Two cases of an unusual neurodermatitis are presented. It is felt that these differ from prurigo and from keratoacanthoma. It is suggested that the condition is a type of pseudoepitheliomatous hyperplasia due to trauma and chronic infection.     

Do viruses play a role in the etiology of keratoacanthoma?

We report on investigations concerning the role of viruses with regard to the etiology of keratoacanthoma. At present, there is no evidence for any involvement of viruses in this process.     

Perianal and perineal keratoacanthoma: Two cases demonstrating histologic similarity to subungual keratoacanthoma

Perianal keratoacanthomas are rare, with 10 cases reported to date. Perineal keratoacanthoma has not previously been described. In this report, we describe two cases of keratoacanthoma, one perianal and one perineal. Both lesions show prominent dyskeratotic keratinocytes, with striking and curious histologic resemblance to subungual keratoacanthoma.     

Ferguson Smith type multiple keratoacanthomas and a keratoacanthoma centrifugum marginatum in a woman from Japan

We report a case of multiple keratoacanthomas on the sun-exposed skin of a 37-year-old woman from Japan. She had experienced 4 similar episodes of evolution and involution of multiple keratoacanthomas during a period of 10 years since she was 27 years old. She was given the diagnosis of Ferguson Smith type keratoacanthoma. This is the seventh Japanese case of Ferguson Smith type keratoacanthoma described in detail in the literature. In addition, the patient was found to have an annular, coral reef-like eruption on the front of her neck, which was diagnosed as a keratoacanthoma centrifugum marginatum. A combination of different variants of keratoacanthoma in 1 patient is uncommon, and only 2 patients with the same combination of lesions, as that seen in our patient, have been reported. Our patient was treated by a relatively low dose (0.5 mg/kg body weight) of etretinate. Both variants of keratoacanthoma showed good response to the treatment. Effectiveness of etretinate for treating keratoacanthoma centrifugum marginatum has only been reported in a few cases. Our patient had no relapse during a period of 15 months after cessation of etretinate treatment.     

Subungual keratoacanthoma—a report of four cases and review of the literature

Subungual keratoacanthoma is a rare benign neoplasm which most commonly occurs in middle-aged Caucasians. It usually presents as a painful, rapidly growing lesion of the terminal phalanx. Radiography consistently demonstrates a well-defined cup-shaped erosion of the underlying bone. Clinically, subungual keratoacanthoma must be distinguished from subungual squamous carcinoma. We report four further cases and discuss the literature.     

Intravascular spread of keratoacanthoma. An alarming but benign phenomenon.

We report a patient with a keratoacanthoma of the scalp in which there was invasion of several medium-sized vessels by the tumour at a distance from the main lesion. A marked inflammatory response within the invaded vessels as well as a benign clinical course do not suggest that this phenomenon represents malignant transformation.     

A case of Grzybowski's generalized eruptive keratoacanthomas

We report a case of Grzybowski's generalized eruptive keratoacanthoma which demonstrates the characteristic features of this rare condition. The recurring nature of the eruption each summer supports the suggestion that UV irradiation may act as a precitating factor in eruptive keratoacanthoma.     

Generalized eruptive keratoacanthoma with vitiligo followed by the development of prurigo nodularis: A case report and published work review

Herein, we report a unique case of generalized eruptive keratoacanthoma (GEKA) in a 47‐year‐old Chinese man presenting with extensive pruritic papules and nodules accompanied by oral lesions. He also had a 2‐year history of vitiligo and long‐term experience of working outdoors. Biopsies were consistent with keratoacanthoma . Interestingly, prurigo nodularis (PN) was found in histopathology at 1‐year follow up. To our knowledge, this is the first report describing a case of GEKA with oral lesions complicated with vitiligo and developed with PN.     

Solitary Keratoacanthoma of the Nipple in a Male. Case Report

A heretofore undescribed localization for solitary keratoacanthoma, namely the skin of the nipple, is reported. The tumor developed in a 69-year-old man who had suffered a trauma in the thorax near the left nipple 5 months before. A possible origin in mammary ducts, considering the breast as a modified sweat gland, is discussed.     

NON-MELANOMA SKIN CANCER AND KERATOACANTHOMA IN FILIPINOS: AN INCIDENCE REPORT FROM KAUAI, HAWAII

Background. Non-melanoma skin cancer is the most common malignancy in the white population of the United States with an estimated 700,000 new cases each year. Regrettably, data on minority racial groups are either scarce or lacking entirely. Methods. This study was designed as a 5-year prospective incidence study of non-melanoma skin cancer and keratoacanthoma by using an island-wide survey of Kauai's Filipino residents and covers the years of 1983 to 1987. Results. Seven basal cell carcinoma (incidence: 12.3/ 100,000), one squamous cell carcinoma (incidence: 1.8/ 100,000) and four keratoacanthoma (incidence: 7/100,000) patients are reported. Conclusions. To the best of our knowledge, this is the first population-based incidence report on non-melanoma skin cancer and keratoacanthoma in this population.     

Riesenkeratoakanthom bei einem immunkompetenten Patienten mit Nachweis von HPV 11

A 47-year-old immunocompetent man presented with a nodule on the right side of the upper lip that appeared suddenly and grew rapidly. Histological examination was consistent with the diagnosis of keratoacanthoma which is often associated with immunosuppression. Low-risk HPV type 11 was detected in the PCR analysis. While formerly one often waited for spontaneous regression of keratoacanthomas, today one routinely treats them as a well-differentiated squamous cell carcinoma. Complete surgical excision was not possible in our patient because of the size of the tumor. Radiation with a cumulative dose of 30 Gray (15 sessions of 2 Gray) led to complete remission. In addition to ultraviolet exposure, trauma, genetic factors and chemical carcinogens, HPV should be considered as a possible cofactor in the etiology of keratoacanthoma.     

Multiple eccrine hidrocystomas successfully treated with cryotherapy in a patient with sarcoidosis

Eccrine hidrocystomas (EHs) are benign cystic lesions of the eccrine ducts. They may have a chronic course and seasonal variation, and have a female predilection. Solitary EH can be easily treated by surgical excision, whereas multiple lesions are difficult to treat. We report a 65‐year‐old woman with sarcoidosis and multiple EHs, who was treated with cryotherapy, which resulted in a reduction in lesion number of > 90%. To our knowledge, this is the first report of cryotherapy used for EH treatment. If this case is confirmed by further studies, cryotherapy may be a viable treatment option for EH.     

Keratoacanthoma: Facts and controversies

The keratoacanthoma and its variants are clinically and histologically heterogenous. Some consider the keratoacanthoma to be benign, whereas others classify it as a subtype of squamous cell carcinoma. The keratoacanthoma is generally treated rather than observed for spontaneous resolution. This hampers evaluation of the true natural history of lesions diagnosed as keratoacanthoma. In addition, studies have not found a reliable marker to differentiate keratoacanthoma from squamous cell carcinoma. It currently remains unclear how the keratoacanthoma relates to squamous cell carcinoma, and continued investigation is necessary.     

Recurrent distal digital keratoacanthoma of the periungual region treated with Mohs micrographic surgery

We report a 42-year-old man who presented with a recurrent painful nodule on the proximal nail fold of the left fifth finger. The tumour had been surgically excised at another department a month earlier, and histological examination had shown a keratoacanthoma. The patient underwent Mohs micrographic surgery, and no recurrence was evident 16 months later. Mohs micrographic surgery appears to be an effective option in the management of this unusual variant of keratoacanthoma, which is often difficult to eradicate.     

Keratoacanthoma centrifugum marginatum associated with mechanical trauma: Response to acitretin—A case report and review of the literature

Keratoacanthoma centrifugum marginatum (KCM) is a very rare variant of keratoacanthoma, characterized with progressive centrifugal growth, central healing, and atrophy. Due to its rarity and lack of distinctive histopathological features, KCM often raises diagnostic and therapeutic challenge. We present a case of a 76‐year‐old Caucasian woman with a single large tumor on her right shin that responded to oral retinoids. The patient presented history of local trauma. The tumor developed over the course of 20 months from a scar. To the best of our knowledge, this is the fifth case of KCM associated with mechanical trauma as a possible triggering factor.     

Expression of the cyclin-dependent kinase inhibitor p27 in keratoacanthoma

BACKGROUND: Keratoacanthomas are characterized by initial rapid enlargement followed by clinical regression. A series of cyclin and cyclin-dependent kinase complexes regulate cell cycle progression. p27(kip) inhibits a variety of cyclin-cyclin-dependent kinase complexes in vitro and may act to hold eukaryotic cells in a quiescent state (G0). OBJECTIVE: We examined expanding and regressing keratoacanthomas for expression of p27(kip). METHODS: An immunohistochemical method was used to visualize and count p27(kip)-labeled cells in 5 expanding and 15 regressing keratoacanthomas. RESULTS: In normal epidermis p27(kip) was found overlying the nuclei of suprabasilar keratinocytes. In expanding keratoacanthoma there was little expression of p27(kip) in nuclei of atypical keratinocytes composing the tumor (1.25 +/- 2.1 labeled cells per high-power field); in regressing keratoacanthoma the nuclei of most suprabasilar keratinocytes in atypical tumor aggregates contained p27(kip) (55.1 +/- 28.6 labeled cells per high-power field). The difference was significant at P values of less than.001. CONCLUSION: The identification of p27(kip) in regressing keratoacanthoma but not in expanding keratoacanthoma suggests that p27(kip) may be playing a role in promoting regression of keratoacanthoma and is a potential target for pharmacologic intervention.     

Keratoacanthoma Arising in an Organoid Nevus During Childhood: Case Report and Literature Review

We report an 11-year-old girl with an organoid nevus of the cheek. She represents the first report of a keratoacanthoma arising within an organoid nevus in childhood.