The role of etretinate (Tegison; Tigason) in the management of keratoacanthoma

Combined 5-Fluorouracil and Er:YAG Laser Treatment in a Case of Recurrent Giant Keratoacanthoma of the Lower Leg

BACKGROUND

Keratoacanthomas are fast-growing squamous tumors, which usually show spontaneous regression. The development of giant variants with an aggressive behavior has been described. Although surgical excision remains the treatment of choice for very large keratoacanthomas, other therapeutic options including laser surgery and topical chemotherapy may be superior in special situations.

OBJECTIVE

The objective was to evaluate the efficacy of Er:YAG laser surgery combined with topical 5-fluorouracil treatment in a case of recurrent giant keratoacanthoma.

METHODS

A 64-year-old woman presented for evaluation and treatment of recurrent tumors in her face and extremities. Despite repeated invasive surgical removal of these lesions, recurrence of fast-growing giant keratoacanthomas developed in the pretibial region of her left lower leg. Owing to recurrence after conventional surgery and the tumor size, a novel treatment method using ablative Er:YAG laser combined with topical 5-fluorouracil was performed.

RESULTS

After four treatments with excellent patient compliance, histologic analysis of punch biopsies revealed tumor-free ulcerations. Complete epithelization was obtained after 9 weeks. Six months after the treatment, no recurrence was observed.

CONCLUSION

The combined use of ablative Er:YAG laser and topical 5-fluorouracil chemotherapy may be considered as an effective treatment option in cases of giant keratoacanthoma when conventional surgery is not indicated.

Persistent keratoacanthoma: challenges in management

BACKGROUND

Keratoacanthoma is a common cutaneous neoplasm, although the persistent form is less common and often more difficult to manage. Multiple treatment approaches have been attempted with variable efficacy. Establishing the diagnosis and selecting a treatment plan for persistent keratoacanthoma is often challenging.

OBJECTIVE

Our purpose is to describe the difficulty one may encounter in the diagnosis and treatment of persistent keratoacanthoma. Hopefully, review of this clinical conundrum may facilitate the management of the reader's future patients.

METHODS

We describe a case of persistent keratoacanthoma where the diagnosis was initially elusive and the management challenging. Our thought process during each stage of diagnosis and management is described in the form of "issues" with references to the appropriate literature.

RESULTS

After several diagnostic and therapeutic interventions, successful treatment was achieved with administration of oral isotretinoin. Long-term remission continued as the dosage was tapered.

CONCLUSION

Persistent keratoacanthoma may be challenging to diagnose and manage, presenting a clinical conundrum. Careful review of the clinicopathologic presentation and an understanding of the various treatment options may result in a successful outcome.

Treatment of a recurrent keratoacanthoma with oral isotretinoin

BACKGROUND

Keratoacanthoma is a benign epithelial tumor that occurs on the sun-exposed skin of elderly people. Development of KAS on functionally and cosmetically important areas such as the face poses the therapeutic challenge to minimize functional and cosmetic damage. Oral isotretinoin (Accutane, Roche Laboratories) has been reported to be an effective treatment of multiple as well as solitary keratoacanthomas.

CASE REPORT

A 45-year-old man with a large keratoacanthoma on the nasal ala, recurrent after surgical excision, was treated with 1 mg/kg/day (80 mg/day) oral isotretinoin (Accutane). Cessation of tumor progression was evident within 1 week after initiation of therapy, and tumor regression was evident within 2 weeks. Tumor size diminished rapidly over the ensuing weeks and complete resolution at 12 weeks was confirmed by biopsy.

CONCLUSION

An initial trial of oral isotretinoin is an alternative to immediate surgical excision for the treatment of large keratoacanthomas in instances when tumor removal would cause considerable cosmetic deformity.

Large keratoacanthomas treated with intralesional interferon alfa-2a

BACKGROUND

Spontaneous involution of giant keratoacanthomas (KAs) can leave large scars or cause mutilation. Human papillomaviruses have recently been demonstrated in KAs. Intralesional interferon alfa-2a (IFN alfa-2a) has been shown to have activity against different epithelial tumors and to have an antiviral effect.

OBJECTIVE

This study was conducted to determine whether it was possible to stop extension of large KAs, to accelerate healing, and to obtain good cosmetic results with intralesional IFN alfa-2a.

METHODS

Six large KAs were treated with intralesional IFN alfa-2a.

RESULTS

Regression was obtained in five cases in 3 to 7 weeks with excellent cosmetic results. The main side effect was pain during injection.

CONCLUSION

Our results suggest that this treatment hastens healing and limits scarring.

Retinoids in cancer prevention and therapy

Retinoids are a class of compounds structurally related to vitamin A. In preclinical studies, all-trans retinoic acid (tretinoin), 13-cis retinoic acid (isotretinoin) and the aromatic retinoids etretinate and acitretin have preventive and therapeutic effects on carcinogen-induced premalignant and malignant lesions. Clinically, chemoprevention with isotretinoin and etretinate has been tested with some degree of success in such indications as basal cell carcinomas, squamous cell carcinomas, superficial bladder tumors and second primary tumors in patients with squamous cell carcinoma of the head and neck. Limited therapeutic success has also been achieved with retinoid treatment of precancerous and cancerous conditions of the skin, oral cavity, larynx, lung, bladder and vulva. Dramatic therapeutic effects have been observed in the treatment of acute promyelocytic leukemia with tretinoin, which leads to very high rate of complete remission. Excellent results were recently reported in the treatment of squamous cell carcinomas of the skin and cervix with a combination of isotretinoin and recombinant interferon alfa-2a (rIFN alfa-2a, Roferon-A). The mechanism of action of retinoids is through modulation of cell proliferation and differentiation. Retinoids vary in their capacity to induce differentiation and to inhibit proliferation in a series of human transformed hematopoietic and epithelial cell lines. Some cytokines potentiate the retinoid-induced cell differentiation and act synergistically with retinoids to inhibit cell proliferation. The pattern of synergism is dependent upon the combination and tumor cell line tested. The discovery of nuclear retinoid receptors has contributed substantially to the understanding of the mechanism of action of retinoids at the molecular level. Further understanding of the molecular biology of retinoids is expected to contribute to a rational design of new retinoids in the future, which in turn may result in improvements in the prevention and therapy of cancer.

Biology of cutaneous squamous cell carcinoma

Nonmelanoma skin cancer is the leading cause of cancer in the United States. Cutaneous squamous cell carcinoma is second only to basal cell carcinoma in prevalence and its incidence is increasing. The biology of squamous cell carcinoma is reviewed under the broad areas of etiology, immunobiology, biochemistry, metastatic potential, and therapy, with emphasis on prevention, diagnosis, and management.

Multiple keratoacanthomas treated with oral retinoids

Multiple eruptive keratoacanthoma of Witten and Zak is a rare disorder characterized by numerous small, eruptive tumors and larger, more typical keratoacanthomas. Affected patients have features of Grzybowski-type keratoacanthomas and Ferguson Smith type. Two patients with multiple keratoacanthomas were treated with oral retinoids. Both patients had hundreds of follicular papules on the trunk and extremities. Less common lesions included nodules with central horn-filled craters more characteristic of classic keratoacanthomas. Retinoid therapy resulted in regression of the larger, more typical keratoacanthomas in both patients. The small follicular keratoacanthomas remained unaffected. Thus oral retinoids are only partially beneficial for the treatment of the Grzybowski type or the Witten and Zak type of multiple eruptive keratoacanthomas.

Large keratoacanthomas in difficult locations treated with intralesional 5-fluorouracil

Keratoacanthoma is a benign tumor; however, it may cause massive destruction of normal tissue during its rapid growth phase. Intralesional 5-fluorouracil (5-FU) has been shown to be an effective treatment for keratoacanthoma. We have successfully treated five patients with large keratoacanthomas in difficult locations. There have been no recurrences during follow-up periods ranging from 18 to 45 months. Intralesional 5-FU may be ineffective for keratoacanthomas that are not rapidly proliferating.