Dermatology Online Journal

Letter: Multiple keratoacanthoma centrifugum marginatum
Aida Khaled MD, Monia Kourda, Becima Fazaa, Rachida Zermani, Mohamed Ridha Kamoun
Dermatology Online Journal 16 (10): 16

Dermatology Department, Charles Nicolle Hospital, Tunis, Tunisia

---

Abstract

Keratoacanthoma centrifugum marginatum (KCM) is a rare variant of keratoacanthoma characterized by a progressive peripheral growth with concomitant central healing. We report here a case of multiple KCM of the lower legs in a 48-year-old man. The lesions had progressively evolved over 3 years. They were multiple asymptomatic and confluent annular plaques of 5 to 20 cm, having papulo-nodular with hyperkeratotic and crusted borders and cicatricial center. Within the centers were numerous firm and pigmented minipapules of 1 to 2 mm. The typical clinical aspect, together with characteristic histological features confirmed the diagnosis of KCM. Herein we will highlight the clinical and histological features of KCM, as well as the different effective treatments. We will also briefly discuss KCM among the other types of keratoacanthomas.

---

Introduction

There are several types of keratoacanthoma (KA) described in the literature, but solitary KA remains the most common form with its three distinct stages: proliferation, maturation, and spontaneous involution [1]. Keratoacanthoma centrifugum marginatum (KCM) is a rare variant of keratoacanthoma that was initially described in 1962 [2] and characterized by a progressive peripheral expanding border with concomitant central healing. It is often solitary, but multiple KCM have been described occasionally [3, 4]. We present here a new case of multiple KCM.

Figure 1a	Figure 1b
Figure 1a. Multiple annular plaques of 5 to 20 cm, having papulo-nodular hyperkeratotic and crusted borders with cicatricial center. Figure 1b. The center of the plaques is atrophic with numerous firm and pigmented minipapules of 1 to 2 mm in size.

A 48-year-old man was referred to our department for a 3-year history of multiple and bilateral keratotic plaques of the lower legs. These lesions had progressive peripheral growth with central healing. The patient was otherwise followed-up in a psychiatric hospital for schizophrenia and was under antipsychotic agents for many years with no clear remission at the time of his referral to our hospital. There were no similar familial cutaneous disorders. Cutaneous examination showed multiple asymptomatic and confluent plaques with annular and polycyclic discontinuous borders of 5 to 20 cm in diameter that were located on the antero-posterior aspects of the lower legs. The borders of the plaques were sometimes papulo-nodular with firm consistency and hyperkeratotic and crusted borders. In some cases the the centers were atrophic with a cicatricial aspect (Figure 1a), but they also contained numerous firm and pigmented minipapules of 1 to 2 mm in size (Figure 1b). Physical examination was otherwise normal.

Histological examination of a cutaneous biopsy performed on a papulo-keratotic border showed hyperkeratosis and acanthosis. The tumor grew in a downward direction extending into the deep reticular dermis and exhibited the formation of keratinous cysts (Figure 2a). The tumor cells had eosinophilic and glassy cytoplasm. There were a few mitoses and necrotic cells; dyskeratosis was observed (Figure 2b). In addition, the hair follicles and sweat glands were decreased in number. The dermis contained a dense lymphohistiocytic inflammatory cell infiltrate. A biopsy specimen from the central area revealed a flattened epidermis and fibrosis. Tissue cultures and stains did not reveal infectious organisms.

Considering the clinical and pathological features, multiple keratoacanthoma centrifugum marginatum was diagnosed. Because of his psychosis, systemic therapy with acitretin was contraindicated. He had received tretinoin 0.1 percent cream but he was lost to follow-up.

Figure 2a	Figure 2b
Figure 2a. Hyperkeratosis and acanthosis. The tumor extends in a downward direction with formation of keratinous cysts (H&E, x100) Figure 2b. The tumor cells have glassy cytoplasm with few mitoses, necrotic cells and dyskeratosis with a dense lymphohistiocytic infiltrate (H&E, x400)

Keratoacanthoma centrifugum marginatum should be differentiated from giant keratoacanthoma by its more significant size, reaching 30 cm in some cases, and by the progressive peripheral expansion. The tumor exhibits raised borders with central clearing. Solitary and multiple variants of KCM may spontaneously regress within 6 to 12 months but our case, as well as other previously reported cases, had progressively enlarged over a prolonged period without spontaneous remission (up to 3 years in the present patient). Keratoacanthoma centrifugum marginatum can be localized to any region of the body but is more frequently on the lower legs. It can be confused with inflammatory dermatoses like hypertrophic lupus erythematosus (HLE), but in this case hyperkeratosis is usually less prominent than that observed in KCM. In addition, verrucous plaques are present concomitantly with discoid lesions and are usually located on the face and arms. Hypertrophic lupus erythematosus may also resemble KCM histopathologically but classic histological features of LE are usually observed and transepithelial elimination of elastotic material may be a notable feature [5]. Infectious dermatoses such as cutaneous tuberculosis, especially lupus vulgaris, atypical mycobacterial infections, or deep fungal infections can also be considered. Indeed, cicatricial progression over a long period of time may be confusing. The infectious diagnoses should be eliminated by tissue culture and histology with specific stains.

Histology remains the gold standard for the diagnosis of classical solitary KA. The tumors are diagnosed by their architecture as well as their cytological features, preferably with an excisional biopsy of the entire lesion including the center and both sides [1]. In KCM, lesions are often too large for excisional biopsy for diagnosis, but the characteristic clinical behavior, the appearance of lesions, histological features (hyperkeratosis and hyperplasia), and cytological features (tumor cells with eosinophilic and glassy cytoplasm, few mitoses) lead to the correct diagnosis.

There is a real debate concerning the nature of solitary KA. Is it a benign epithelial tumor or, as suggested by Ackerman et al., a specific type of squamous cell carcinoma (SCC), which is now commonly believed [6]? Taking into account the different cases of KCM reported by the literature, most of them had a spontaneous involution. Moreover, there were no cases that had a malignant evolution with metastases. This is in favor of the first hypothesis supporting the benignity of KA or at least of KCM.

Keratoacanthoma centrifugum marginatum has no known etiology and has never been described in association with visceral malignancy. It is an acquired disorder of adulthood with no genetic predisposition. It should be differentiated from multiple KA as a component of Muir-Torre syndrome, multiple sebaceous neoplasms, and one or more low-grade visceral cancers, usually of gastrointestinal or urogenital origin.

Oral retinoids (acitretin, etretinate, or isotretinoin 0.5-1 mg/kg/day) are the treatment of choice. They should be maintained until complete clearance of the lesion [3, 7]. But, prudent gradual reduction of the dose, followed by termination is necessary to avoid recurrence. Our patient could not have this therapy because of the potential of exacerbating his psychosis. Other treatment modalities have been successfully used such as topical 5-fluorouracil, intralesional bleomycin, or Mohs micrographic surgery [8, 9, 10].

References

1. Karaa A, Khachemoune A. Keratoacanthoma: a tumor in search of a classification. Int J Dermatol. 2007; 46 (7): 671-8. Review. [PubMed]

2. Miedzinski F, Kosakiewicz J. Das Keratoakanthoma centrifugum: eine besandera Varieät des Keratoakanthoms. Hautarzt 1962; 13:348-52. German. [PubMed]

3. Ogasawara Y, Kinoshita E, Ishida T, Hamamoto Y, Fujiyama J, Muto M. A case of multiple keratoacanthoma centrifugum marginatum: response to oral etretinate. J Am Acad Dermatol. 2003; 48 (2): 282-5. [PubMed]

4. Cherif F, Mebazaa A, Kort R, Makni N, Haouet S, Mokni M, Ben Osman Dhahri A. Kératoacanthomes centrifuges marginés multiples. Ann Dermatol Venereol. 2002; 129 (4 Pt 1): 413-5. French. [PubMed]

5. Daldon PE, Macedo de Souza E, Cintra ML. Hypertrophic lupus erythematosus: a clinicopathological study of 14 cases. J Cutan Pathol. 2003; 30 (7): 443-8. [PubMed]

6. Hodak E, Jones RE, Ackerman AB. Solitary keratoacanthoma is a squamous-cell carcinoma: three examples with metastases. Am J Dermatopathol 1993; 15: 332. [PubMed]

7. Street ML, White JW, Gibson LE. Multiple keratoacanthomas treated with oral retinoids. J Am Acad Dermatol 1990; 23: 862-6. [PubMed]

8. Yuge S, Godoy DA, Melo MC, Sousa DS, Soares CT. Keratoacanthoma centrifugum marginatum: response to topical 5-fluorouracil. J Am Acad Dermatol. 2006; 54 (5 Suppl): S218-9. [PubMed]

9. Torre C, Losada A Cruces MJ. Keratoacanthoma centrifugum marginatum: treatment with intralesional bleomycin. J Am Acad Dermatol 1997; 37: 1010-1. [PubMed]

10. Benest L, Kaplan RP, Salit R, Moy R. Keratoacanthoma centrifugum marginatum of the lower extremity treated with Mohs micrographic surgery. J Am Acad Dermatol 1994; 31: 501-2. [PubMed]

© 2010 Dermatology Online Journal