Pilomatricoma, a benign tumor arising from hair follicle matrix cells, commonly appears as a slow-growing, firm, nontender nodule on the head and neck region. This report describes an atypical variant of pilomatricoma in a 12-year old Filipino female who presented with a 4-week history of a solitary rapidly-enlarging nodule morphologically resembling a proliferating keratoacanthoma on the right arm. Histopathologic diagnosis of pilomatricoma with suppurative and granulomatous inflammation was made and wide local surgical excision was done. This article highlights the importance of including pilomatricoma in the differential diagnosis of pediatric patients presenting with a firm, solitary, rapidly-growing nodule on sites other than the head and neck region.

Pilomatricoma or calcifying epithelioma of Malherbe is a benign tumor originating from the matrix of hair follicles. Clinically, these tumors are classified as familial, perforating, multinodular, exophytic, anetodermic, bullous, and giant pilomatricomas. The bullous variety is observed only in 3 to 6% of cases. Furthermore, multiple pilomatricomas are rare and are usually associated with genetic disorders. To date, only 13 cases of bullous pilomatricoma and 8 cases of multiple pilomatricomas have been reported in Korean dermatologic literature. Among these cases, no case of multiple bullous pilomatricomas has been reported. This report describes a 23-year-old healthy man who was diagnosed with multiple pilomatricomas with bullous features, based on clinical and histopathological findings.
Hair Follicle ; Humans ; Pilomatrixoma* ; Young Adult

BACKGROUND: Although histological diagnosis of pilomatricoma is not difficult because of its unique histological features, cytological diagnosis through fine-needle aspiration cytology (FNAC) is often problematic due to misdiagnoses as malignancy. METHODS: We reviewed the cytological features of 14 cases of histologically-proven pilomatricoma from Korea Cancer Center Hospital, with a discussion on the diagnostic pitfalls of FNAC. RESULTS: Among 14 cases of pilomatricoma, 10 (71.4%) were correctly diagnosed through FNAC, and two (14.3%) were misdiagnosed as carcinoma. Cytologically, all cases had easily recognizable clusters of basaloid cells and foreign body-type multinucleated cells. Although ghost cells were also found in all cases, some were inconspicuous and hardly recognizable due to their small numbers. CONCLUSIONS: An accurate diagnosis of pilomatricoma in FNAC is feasible with consideration of clinical information and close examination of ghost cells.
Biopsy, Fine-Needle ; Diagnosis ; Diagnostic Errors ; Korea ; Pilomatrixoma

Malignant pilomatricoma (pilomatrical carcinoma) is a rare, locally occurring malignant tumor with a high rate of recurrence in the case of incomplete excision. This tumor has two characteristics. First, recurrences of pilomatrical carcinoma are common; second, distant metastasis is rare, but if it occurs, it is very fatal. It has characteristic features of high mitotic counts, cellular atypia, and local invasion. Although fine needle aspiration and excisional biopsy could help to confirm this tumor diagnosis, pathologic findings are critical. Pilomatricomas have some characteristic features in histological aspect, such as epithelial islands of basaloid cells and shadow cells or ghost cell. Also, various types of immunohistochemical staining are used to confirm the diagnosis. Despite the lack of clear surgical criteria, treatment is a wide local excision with histologically clear resection margins with or without adjuvant radiotherapy.
Biopsy ; Biopsy, Fine-Needle ; Cheek* ; Diagnosis ; Facial Neoplasms ; Humans ; Infant* ; Islands ; Neoplasm Metastasis ; Pilomatrixoma* ; Radiotherapy, Adjuvant ; Recurrence

No abstract available.
Keratoacanthoma* ; Pilomatrixoma*

No abstract available.
Pilomatrixoma* ; Vaccination*

No abstract available.
Pilomatrixoma*

PURPOSE: To report the relative frequency and clinical characteristics of patients with benign eyelid tumors. METHODS: A retrospective study of 192 consecutive patients admitted to Korea University Ansan Hospital with benign eyelid tumor between January 2009 and December 2014 was undertaken, and clinical records including age, sex, involved site, and pathology of tumors were reviewed retrospectively. All eyelid tumors were confirmed histopathologically. RESULTS: The sexual distribution revealed 87 males and 105 females with benign eyelid tumors. The mean age at diagnosis was 42.6 +/- 19.2 years. Molluscum contagiosum (5.5 +/- 3.5 years) and pilomatrixoma (14.0 +/- 15.6 years) were generally found in younger individuals, while seborrheic keratosis (60.2 +/- 15.8 years) and squamous cell papilloma (50.5 +/- 13.4 years) occurred predominantly in elderly patients. Tumors were most common on the upper lid (63.0%). The four most frequent subtypes were melanocytic nevus (37.5%), epidermal cyst (8.3%), squamous cell papilloma (5.7%), and seborrheic keratosis (5.2%). CONCLUSIONS: The most common histopathological diagnosis of benign eyelid tumors was melanocytic nevus. The results of this study provide epidemiological information that will be useful for diagnosis and therapy of such tumors.
Aged ; Diagnosis ; Epidermal Cyst ; Eyelids* ; Female ; Gyeonggi-do ; Humans ; Keratosis, Seborrheic ; Korea ; Male ; Molluscum Contagiosum ; Nevus, Pigmented ; Papilloma ; Pathology ; Pilomatrixoma ; Retrospective Studies

Amelanotic melanoma comprises only 1.8~8.1% of malignant melanomas, and is difficult to diagnose clinically due to the lack of the diagnostic evidence of clinical pigmentation. To our knowledge, it is rarely reported, and only 10 cases have been reported in the Korean dermatological literature. It presents rather conflicting features such as a pink or red macule, papule, plaque, or nodule mimicking various benign and malignant conditions; therefore, it is difficult to diagnose. We performed a review of six patients with amelanotic melanoma focusing on differential diagnosis, particularly at the time of the initial visit. Clinical impressions included pyogenic granuloma, dermatofibrosarcoma protuberans, eccrine poroma, epidermal cyst, keloid, pilomatricoma, and squamous cell carcinoma in addition to malignant melanoma. The biopsy specimens were consistent with malignant melanoma with little or no melanin pigment on hematoxylin and eosin and Fontana-Masson stains. Four of the six patients were positive for S-100 and HMB-45, but two patients were positive for S-100 only. We report these cases to remind clinicians of the necessity of including malignant melanoma in the differential diagnosis process when patients show poor and unpredictable responses to treatment after a clinical diagnosis of other benign and malignant conditions.
Biopsy ; Carcinoma, Squamous Cell ; Coloring Agents ; Dermatofibrosarcoma ; Diagnosis ; Diagnosis, Differential* ; Eosine Yellowish-(YS) ; Epidermal Cyst ; Granuloma, Pyogenic ; Hematoxylin ; Humans ; Keloid ; Melanins ; Melanoma ; Melanoma, Amelanotic* ; Pigmentation ; Pilomatrixoma ; Poroma

No abstract available.
Pilomatrixoma* ; Vaccination*