Porokeratosis of Mibelli - literature review and a case report

CASE REPORT 179 s Porokeratosis of Mibelli - literature review and a case report* Poroqueratose de Mibelli - revisão da literatura e relato de um caso Flávia Regina Ferreira1 Fernando Augusto Nogueira Mendes Tagliarini2 Leopoldo Duailibe Nogueira Santos2 Marcia Lanzoni de Alvarenga Lira3 DOI: http://dx.doi.org/10.1590/abd1806-4841.20132721 Abstract: Porokeratosis is a disorder of epidermal keratinization characterized by annular plaques with an atrophic center and hyperkeratotic edges, and includes a heterogeneous group of disorders that are mostly inherited in an autosomal dominant form. This report describes a 5 year-old female patient, with porokeratosis of Mibelli confirmed histopathologically. The rarity of this disorder, its clinical exuberance and the destructive character of the lesions, as well as the facial and mucosal involvements, unusual in this form of porokeratosis, and also its onset in early childhood motivated this report. Keywords: Child; Parakeratosis; Porokeratosis Resumo: A poroqueratose é uma desordem da queratinização epidérmica caracterizada por placas anulares com centro atrófico e bordas hiperqueratóticas, e inclui um grupo heterogêneo de desordens que são na sua maioria herdadas de forma autossômica dominante. O presente caso refere-se a uma paciente feminina de 5 anos de idade, com poroqueratose de Mibelli confirmada histologicamente. A raridade desta desordem, a exuberância clínica e o caráter destrutivo das lesões, o acometimento facial e mucoso pouco usuais nesta forma de poroqueratose e o início na infância precoce motivaram este relato. Palavras-chave: Criança; Paraceratose; Poroceratose INTRODUCTION Porokeratosis is a primary disorder of epidermal keratinization, characterized by annular plaques with an atrophic center and hyperkeratotic edges.1,2 The cornoid lamella, a column of parakeratotic cells that occupies the small epidermal invaginations, constitutes a characteristic histopathological finding, primordial for its diagnosis.1-7 Porokeratosis include a group of heterogeneous disorders that represent diverse phenotypic expressions of the same genetic defect, which is mainly inherited in an autosomal dominant form.1,3 Porokeratosis can be classified in localized and disseminated forms (Figure 1).2 Classic porokeratosis, the most common variant, was first described in 1893 by Vittorio Mibelli, hence the name porokeratosis of Mibelli (PM).1,3,4,6,8 The first Brazilian description was made in 1934 by Niemayer.9 This is a rare, chronically progressive disease, arising either from an autosomal dominant inheritance or, more commonly, appearing as a random form.1,3 It is more frequent in males, starting in childhood or adolescence.1,3,5,6,9 Lesions may affect any tegument part, being more prevalent in the trunk and extremities.2-4,10 The rarity of this disorder, its clinical exuberance and the destructive character of the lesions, as well as the facial and mucosal involvements, unusual in this form of porokeratosis, and also its start in early childhood motivated this report. Received on 28.04.2013. Approved by the Advisory Board and accepted for publication on 30.05.2013. * Work performed at the Dermatology Service of the University Hospital of Taubaté – University of Taubaté (HUT-UNITAU) – Taubaté (SP), Brazil. Conflict of interest: None Financial Support: None 1 2 3 MD, MSc at São Paulo Federal University – Paulista Medical School (UNIFESP-EPM) – Assistant Professor of Dermatology Discipline in the Medicine Department of the University of Taubaté (UNITAU) – Taubaté (SP), Brazil. MD – Specialization (in course) at the Dermatology Service of the University Hospital of Taubaté – University of Taubaté (HUT-UNITAU) – Taubaté (SP), Brazil. Specialist in Pathological Anatomy – Assistant professor of the Pathology Discipline of the Medicine Department in the Medicine Department of the University of Taubaté (UNITAU) – Taubaté (SP), Brazil. ©2013 by Anais Brasileiros de Dermatologia An Bras Dermatol. 2013;88(6 Suppl 1):179-82. 180 Ferreira FR, Santos LDN, Tagliarini FANM, Alvarenga Lira ML CASE REPORT This is a five year-old, brown-skinned female patient, with a history of developing erythematoushyperchromic plaques with slightly elevated edges and atrophic center located on the face (malar areas bilaterally, inferior eyelids, nose and chin) since the age of one and a half years (Figures 2 and 3). Similar lesions were presented, although with more elevated borders, on the dorsal area of the left-hand and the lateral region of the second right-hand digit (Figure 4). Dermatologic examination showed that the inferior palpebral lesions extended to the mucosa of the eye, starting an ectropion growth and in the left nasal lesion there was a meliceric crust, by a recent impetigo process (already in treatment). There were not any relevant personal antecedents. Family members were also examined and no important cutaneous alterations were found. Histopathological examination of the material collected from the dorsal area of left hand revealed cornoid lamella and hypogranulosis, confirming the diagnosis of porokeratosis (Figure 5). FIGURE 2: Face – erythematous-hyperchromic plaques with slightly elevated edges and atrophic center DISCUSSION Classic porokeratosis or porokeratosis of Mibelli (PM) is a chronic, progressive dermatosis, that may rarely evolve with spontaneous remission.3,4,8 Regarding the mode of inheritance, it may arise in an autosomal dominant form, more commonly in a random form, which we believe was the case for this patient, since there were not any relatives affected by the disease.1,4 Nonetheless, a genetic evaluation for this patient and her family is advisable, to address genetic counseling issues for the future. FIGURE 3: Details of the facial lesions Porokeratosis Localized Porokeratosis of Mibelli Linear porokeratosis FIGURE 1: Clinical forms of porokeratosis An Bras Dermatol. 2013;88(6 Suppl 1):179-82. Disseminated Punctate porokeratosis Actinic superficial disseminated porokeratosis Superficial disseminated porokeratosis Palmo-plantar disseminated porokeratosis Porokeratosis of Mibelli - literature review and a case report FIGURE 4: Lateral region of the second right-hand digit– erythematous plaques with elevated edges and atrophic center FIGURE 5: Histopathological exam: cornoid lamella (1) and hypogranulosis (2). (HE 400X) PM consists of one or more plaques, usually a small number of them, which may occur anywhere in the body, more frequently in extremities, especially hands and feet, with unilateral distribution.1,3-5 Other areas, such as neck, shoulders and genitals may also be affected. The occurrence of facial and mucosal lesions, as observed in this patient, is rare.3 It starts, in general, during childhood or adolescence, being more prevalent in males (ratio of 23:1).2,3,8,10 It is also more frequent in Caucasians.7 Lesions are asymptomatic with an indolent evolution.3 The case report (...truncated)