Pilomatricoma in Children: Common but often Misdiagnosed

Abstract

IntroductionPilomatricoma, also known as calcifying epithelioma of Malherbe, is a benign skin tumor arising from the outer root sheath cell of the hair follicle. In the pediatric population, this skin neoplasm is relatively common, especially in the head and neck region (1). Despite the fact that pilomatricomas are frequent occurring skin tumors in children, that the history is typical of a slowly growing tumor and that the characteristic clinical appearance is of a superficial hard mass with discoloration, this lesion is often misdiagnosed or not recognized and confused with other skin conditions (2). The treatment however is straightforward : after complete surgical excision, recurrence is unlikely and malignant degeneration is very rare (3).In this article, we present several cases of pilomatricomas with a classical presentation together with a brief review of the literature. We also describe an atypical case : a 1.5-year-old girl with a rapidly growing mass in the face, suggestive for a malignant tumor, in whom the final diagnosis of pilomatricoma was only made after incisional biopsy. Shortly after this surgery she developed a recurrence and complete surgical excision was performed with an uneventful postoperative follow-up. Pilomatricomas with Typical PresentationA 6-year old girl was referred with a slowly growing mass on the left elbow. The tumor had been present for 2 months, was adherent to the overlying skin, but mobile from underlying tissues, with a purple discoloration (Fig. 1). A pilomatricoma was suspected because of this typical appearance and complete excision was performed. Pathological examination confirmed the clinical diagnosis and the postoperative follow-up during 1 year was uneventful.A 7-year old girl presented with a slowly growing, painless tumor on the right cheek (Fig. 2). The mass had been present for several months. Clinical examination revealed a mobile, red-bluish irregular mass with calcifications in the right preauricular region, fixed to the ulcerated overlying skin. A pilomatricoma was suspected based on the clinical signs and the lesion was excised. The pathology report confirmed the diagnosis and the postoperative follow-up during 18 months was uneventful.A 20-year old girl was seen with a pendulous tumor at the back of the left thigh (Fig. 3). The mass had been present for 1 year, growing slowly. At clinical examination, a purple tumor was seen with irregular nodes, hard at palpation but mobile from the underlying tissues. A pilomatricoma was diagnosed because of the typical signs and excision with primary closure was performed. The clinical diagnosis was confirmed by histological examination and follow-up during 1 year was uneventful.A 5-year old girl consulted for a mass in the right preauricular region. This had been present for 7 months and was slowly growing. A painless, hard 1.5 cm lesion was palpated, mobile from the underlying tissues with irregular calcifications (Fig. 4). Pilomatricoma was suspected and the lesion was excised ; the pathology report confirmed the...

Characterizing pilomatricomas in children: a single institution experience

“…Fine needle aspiration can obtain a definitive diagnosis via the histopathologic identification of ghost (shadow) cells and/or basaloid cells with or without calcium deposits, but is rarely indicated in children [2,24]. Despite a characteristic appearance, misdiagnosis frequently occurs, and can lead to unnecessary imaging studies [37]. In this study, all patients were taken to the operating room based on clinical exam only, and pre-operative imaging was not used as a part of the pre-operative evaluation.…”

Pilomatricoma of the breast in an adolescent girl: sonographic findings

“…More than 60 % of tumors appear during the first 2 decades of life, and 40 % of tumors occur in children younger than 10 years. Pilomatricomas are one of the most common solid cutaneous or subcutaneous tumors in children; only epidermoid cysts are more common [12,13]. Pilomatricomas occur at a slightly higher rate in females (female-to-male incidence ratio = 3:2) and most frequently appear on the head, neck, and, in decreasing order, upper extremities, trunk, and lower extremities.…”

“…Spontaneous regression has never been observed, and complete surgical excision is the treatment of choice [12].…”

“Tumour Perplex” called pilomatricoma — Report of a case with confounding chest wall mass in an adult male and its literature review

“…Chenantals Malherbe was the first to describe the "calcifying epithelioma of Malherbe" in 1880, later named as pilomatrixoma, and finally as pilomatricoma [1,4]. This largely benign skin lesion derived from hair matrix cells still remains a diagnostic pitfall for clinicians and pathologists alike [5].…”