| Abstract|| |
Keratoacanthoma (KA) is a rapidly evolving tumor, composed of keratinizing squamous cells originating in pilosebaceous follicles and resolving spontaneously if left untreated. It is relatively uncommon in dark-skinned and occurs in middle aged individuals. Males are three times more affected than females. It presents as firm, rounded, flesh-colored or reddish papule; with a rapid growth phase followed by spontaneous healing over three months. Two types of KA exist i.e., solitary and multiple. There are three rare clinical variants of solitary KA, namely giant KA, keratoacanthoma centrifugum marginatum (KCM) and subungual KA. In KCM, lesions are large, reaching upto 20cms. There is peripheral extension with raised, rolled border and atrophy in the center. There is no tendency toward spontaneous involution. The most common locations are dorsa of hands and legs, lesions on scalp being rare. A rare case of KCM occurring on scalp which is an unusual site is reported.
Keywords: Keratoacanthoma centrifugum marginatum, scalp, surgical excision
|How to cite this article:|
Phiske MM, Avhad G, Jerajani H R. Keratoacanthoma centrifugum marginatum at an unusual site. Indian J Dermatol 2013;58:74-6
What was known?
KCM is itself very rare and distinct type of keratoacanthoma which usually occurs over extremities and scalp is unusual site for development of lesion. Treatment is difficult as lesion of KCM present with large raised,rolled borders
with peripheral extension.
| Introduction|| |
Keratoacanthoma (KA) is a rapidly evolving tumor, composed of keratinizing squamous cells originating in pilosebaceous follicles and resolving spontaneously if left untreated. It is relatively common, especially in whites occurring in middle age while being uncommon in dark-skinned. Males are three times more affected than females. It presents as firm, rounded, flesh-colored or reddish papule; with a rapid growth phase becoming 10-20 mm and then spontaneous healing taking place over three months.  Two types of KA exist i.e., solitary and multiple. There are three rare clinical variants of solitary KA, namely giant KA, keratoacanthoma centrifugum marginatum (KCM) and subungual KA. In KCM, lesions are large, reaching upto 20 cms. There is peripheral extension with raised, rolled border and atrophy in the center. There is no tendency toward spontaneous involution. The most common locations are dorsa of hands and legs, lesions on scalp being rare.  We report a rare case of KCM occurring on the scalp which is an unusual site.
| Case Report|| |
A 62-year-old male, watchman by occupation presented with asymptomatic raised lesion on scalp since one year. He gave a history of excessive sun exposure but denied prior trauma. Lesion had developed de novo, as a pea sized lesion with gradual increase to cover entire vertex. A surgical intervention done subsequently resulted in development of a non-healing ulcer. He did not have any systemic complaints. Cutaneous examination revealed a single, irregular, 12 × 15 cm, yellowish plaque on vertex of scalp with nodular surface and a central crater [Figure 1]. On palpation, the plaque was firm, non-tender, non-indurated and not attached to underlying structure. Multiple seborrheic keratosis of various sizes were seen on bilateral temple area and forehead. There was no regional and systemic lymphadenopathy. His haemogram, chemistry profile, X-ray chest and skull were normal. CT scan of brain did not show any abnormality. Ultrasonography of lesion showed ill defined hypo echoic mass involving epidermis, dermis and subcutaneous tissue.
|Figure 1: A single, irregular, 12 × 15 cm, yellowish plaque on vertex of scalp with nodular surface and a central crater.|
Click here to view
Deep punch biopsy revealed exoendophytic, globular, well circumscribed central cup shaped crater, epidermal invagination with marked hyperkeratosis and horn cyst with rich keratin filled crater imparting glassy appearance and well demarcated regular base . Epidermis formed buttress over the pseudhorn cyst [Figure 2] and [Figure 3]. Dense nodular lymphocytic infiltrate was seen in the upper dermis [Figure 4]. Deeper dermis, appendegeal structures and subcutaneous tissue were unremarkable. Marked epidermal proliferation with crater formation with horn pearls and inflammatory infiltrate at the base of the lesion was suggestive of a fully developed lesion of KCM. Complete surgical excision with grafting was done successfully with dramatic improvement with no recurrence at 9 months [Figure 5].
|Figure 2: Exoendophytic, globular, well circumscribed central cup shaped crater, epidermal invagination with marked hyperkeratosis and horn cyst with rich keratin filled crater imparting glassy appearance and well demarcated regular base|
Click here to view
| Discussion|| |
Keratoacanthoma centrifugum marginatum was first described in 1965 by Belisario as a separate entity.  It is rare with only 31 cases reported in the world literature. It is an acquired disorder of adulthood with no genetic predisposition.  The etiology is multifactorial that includes chronic ultraviolet ray exposure, smoking, contact with chemical carcinogens like pitch, mineral oil, tar, trauma and vaccination.  The role of human papilloma virus remains inconclusive but in one study, HPV type 6 and 11 were detected within the lesion.  It has never been described in association with visceral malignancy. There were no cases that had a malignant evolution with metastases. This favors the hypothesis supporting the benignity of KCM.  It can be localized to any region of the body but is more frequently seen on dorsum of hands and legs. 
Progressive peripheral extension with a raised rolled-out margin and atrophy at the centre is a characteristic feature of KCM. The margin of the lesion showing multiple comedonal orifices giving rise to a cribriform pattern may represent a unique phenomenon of KCM. It is hypothesized that this typical appearance may arise as a result of sequential involvement of multiple adjacent hair follicles in a centrifugal fashion. 
KCM does not show tendency for spontaneous regression, a feature also seen in giant KA, which grows rapidly reaching a size of 5 cm or more and occurring commonly on nose and eyelids. KCM is differentiated from giant KA by absence of downward vertical spread and destruction of underlying tissue. Nevertheless, in giant KA spontaneous involution takes place after several months, often accompanied by detachment of a large keratotic plaque.  The other differential diagnoses include squamous cell carcinoma, lupus vulgaris, botryomycosis, blastomycosis-like pyoderma and pseudoepitheliomatous hyperplasia, hypertrophic lupus erythematosus, atypical mycobacterial infections, or deep fungal infections. 
There are reports that KCM has been treated successfully with oral retinoids (acitretin, etretinate, or isotretinoin 0.5-1 mg/kg/day) which should be given until complete clearance of lesion.Surgical intervention is a preferred mode of therapy keeping in mind that a wide excision is performed to prevent subsequent recurrence. If surgery is not possible radiation therapy can be considered. Other treatment modalities successfully used include topical 5-fluorouracil, intralesional injections of interferon alpha, methotrexate, or bleomycin, or Mohs micrographic surgery.
In KCM, lesions are usually too large for excisional biopsy for diagnosis, but certain characteristic features like clinical behavior, appearance of lesions, histological features (hyperkeratosis and hyperplasia), and cytological features (tumor cells with eosinophilic and glassy cytoplasm, few mitoses) help clinch the correct diagnosis.
| References|| |
|1.||MacKie RM, Quinn AG. Non-Melanoma skin cancer and other epidermal tumors. In: Burns T, Breathanach S, Cox N, editors. Rook's textbook of dermatology: 7 th ed. USA: Blackwell Publishing; 2004. p. 36.1-50. |
|2.||Kirkham N. Tumors and cysts of the epidermis. In: Elder DE, editors. Lever's histopathology of the skin. 10 th ed. USA: Lippincott Williams and Wilkins; 2009. p. 791-850. |
|3.||Belisario JC. Brief review of keratoacanthomas and description of keratoacanthoma centrifugum marginatum. Aust J Dermatol 1965;8:65-75. |
|4.||Vlckova-Laskoska MT, Laskoski DS. Keratoacanthoma centrifugum marginatum: A rare atypical variant of keratoacanthoma. Clin Exp Dermatol 2008;33:259-61. |
|5.||Cerroni L, Curl H. Keratoacanthoma. In: Freedberg IR, Eisen AZ, Wolff K, Austen FK, Goldsmith LA, Katz SA, editors. Fitzpatrick's Dermatology in General Medicine. 6 th ed. New York: McGraw Hill; 2003. p. 760-7. |
|6.||Lo Shiavo A, Pinto F, Degner AM, Bucci M, Ruocco V. Keratoacanthoma centrifugum marginatum. Possible etiological role of papillomavirus and therapeutic response to etretinate. Ann Dermatol Venereol 1996;123:660-3. |
|7.||Khaled A, Kourda M, Fazaa B, Zermani R, Kamoun MR. Multiple keratoacanthoma centrifugum marginatum. Dermatol Online J 2010;16:16. |
|8.||Epidermal Nevi, Neoplasms and Cysts. In: James WD, Berger TG, Elison DM, editors. Andrews' Disease of the Skin Clinical Dermatology. 10 th ed. Canada: Saunders Elsevier; 2006. p. 633-84. |
|9.||Das K, Das NK, Rathore VS, Kundu S, Choudhury, Gharami RC, et al. Keratoacanthoma centrifugum marginatum: Unresponsive to oral retinoid and successfully treated with wide local excision. Licensee PAGE Press, Italy. Dermatol Rep 2010;2:4081. |
|10.||Kirkham N. Tumors and cysts of the epidermis. In: Elder DE, Elenitsas R, Johnson BL, Murphy GF, editors. Lever's Histopathology of the Skin. 9 th ed. Philadelphia: Lippincott Raven; 2005. p. 849-51. |
What is new?
First time from India we are reporting case of KCM presenting over scalp which is successfully treated with surgical excision without any recurrence.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]