Trichofolliculoma

Nevus lipomatosus cutaneous superficialis (NLCS) and trichofolliculoma (TF) are both rare cutaneous hamartomatous lesions. However, the coexistence of NLCS and TF as a single lesion has been reported only in two other cases, that too in middle-aged individuals. We report the first case of NLCS associated with TF in pediatric age group and also, to the best of our knowledge, the first case reported from India.

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Trichofolliculoma is an uncommon hair follicle hamartoma. It usually appears during adulthood on the face or scalp as a single, asymptomatic, skin-colored papule/nodule with small protruding hairs. Histopathological features are diagnostic. Very rare congenital cases have been reported. Herein, we report a congenital trichofolliculoma in a 15-year-old girl.

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Trichofolliculoma (TF) is a follicular hamartoma in which hairs protruding out of single orifice. To the best of my knowledge, only two auricular TF has been reported in the English literature. Moreover, clinically TF have been described to mimic malignancy. I present a case of an adult female with mass at the intertragal notch of the left auricle for several years. The clinical diagnosis was thought to be epidermoid cyst, accessory tragus, and other benign skin adnexal tumor. To prevent recurrence, the wide local excision of the mass was performed...

Trichofolliculoma is a rare benign tumor of the skin, with distinct pilar differentiation and a predilection for the head and neck. To the best of the authors' knowledge, only 10 cases of eyelid trichofolliculoma has been described in the English literature. Moreover, these benign hair follicle lesions have been reported to clinically mimic eyelid malignancy. The authors report a case of a 58-year-old woman with a nodule on the eyelid margin, with typical clinical features and characteristic histopathological findings aiding the diagnosis of trichofolliculoma...

INTRODUCTION: Benign cutaneous tumors with follicular differentiation are alleged to differentiate toward parts of the hair follicle. Connexin 43 (Cx43) is a gap junction protein, the tumoral role of which has been investigated in several types of tumors. OBJECTIVE: To study the pattern of expression of Cx43 in benign cutaneous tumors with follicular differentiation and to compare it with that shown by their alleged anatomical counterparts of the hair follicle. MATERIALS AND METHODS: Five cases each of trichofolliculoma, trichilemmoma, fibrofolliculoma/trichodiscoma, trichoblastoma, trichoepithelioma, pilomatrixoma, and proliferating trichilemmal tumor, 3 cases of pilar sheath acanthoma, and 1 case of tumor of the follicular infundibulum were examined...

BACKGROUND AND OBJECTIVES: The histological differential diagnosis between benign trichogenic skin tumors and basal cell carcinoma may be challenging. We therefore set out to investigate whether expression of CD10, a cell surface protein with neutral endopeptidase activity, might be a suitable marker for the histological differential diagnosis of trichogenic skin tumors. PATIENTS AND METHODS: We immunohistochemically analyzed 119 cases of benign trichogenic skin tumors and basal cell carcinoma...

Trichofolliculoma (TF) is a hamartomatous hair follicle-related tumor, clinically described as a dome-shaped papule with a central pore crossed by one or more silky white hairs. Histologically, it described as a cystic cavity containing keratinous debris, hair shaft fragments, and numerous hair follicles arising from its linings. Collision or compound tumors are a coexistence of two or more identifiable tumors in the same lesion. We present a case of a 47-year-old man with a lesion on his left cheek clinically characterized as a TF...

An association between steatocystoma multiplex (SCM) and eruptive vellus hair cysts (EVHCs) has been recognized. Steatocystoma multiplex and EVHC have similar clinical features but distinctive histologic features. Rare cases of co-occurrence of these conditions have been known to occur on the trunk and the forehead. We report a rare case of the simultaneous occurrence of SCM, EVHC, and trichofolliculomas localized to the forehead.

Panfolliculoma (PF) is a rare benign tumor with signs of differentiation toward all components of the hair follicle (HF). Cystic panfolliculoma (CPF) is a subset of PF with histological similarity to trichofolliculoma making the differential diagnosis difficult in some cases. Immunohistopathological investigations of PF have been reported; however, previous studies focused mostly on the expression profile of the outer root sheath markers. Herein, we report a case of CPF. A panel of antibodies was developed and used for the detection of the expression of cytokeratin (CK) 10, CK13, CK14, CK15, hair-hard keratin (AE13) and EpCAM within the lesion, supporting the differentiation of all epithelial lineages of the HF and the diagnosis of CPF...

Some authors have reported that the secondary hair follicles in trichofolliculomas (TF) undergo regressive changes and are subsequently replaced by the developed sebaceous elements, and that folliculosebaceous cystic hamartoma (FSCH) is a TF at a very late stage. In the present study, we revaluated the histopathological features of 40 TF lesions, focusing on their chronological changes. The results of the present study indicate that while the secondary follicles in the TF exhibited the hair cycle, the normal hair cycle was out of control, and tertiary hair follicles randomly developed from the involuting secondary follicles...

Trichoadenoma is a rare benign, slowly growing, cutaneous tumour of the hair follicle first described by Nikolowski in 1958. It presents as a non-specific nodule over the face or buttocks. However, unusual sites such as the neck, upper arm, thigh, shoulder, and shaft of the penis may also be affected. The tumour is less mature than a trichofolliculoma and is more differentiated than a trichoepithelioma with a differentiation towards the infundibular portion of the pilosebaceous canal. Histologically, it consists of numerous infundibulocystic structures present throughout the dermis, few of which are lined by eosinophilic epidermal cells with attempted glandular formation and contain laminated keratin, without evidence of hair follicle formation...

No abstract text is available yet for this article.

No abstract text is available yet for this article.

1,25 dihydroxyvitamin D (1,25(OH)2D), the active metabolite of vitamin D, and calcium regulate epidermal differentiation. 1,25(OH)2D exerts its effects through the vitamin D receptor (VDR), a transcription factor in the nuclear hormone receptor family, whereas calcium acts through the calcium sensing receptor (Casr), a membrane bound member of the G protein coupled receptor family. We have developed mouse models in which the Vdr and Casr have been deleted in the epidermis ((epid) Vdr (-∕-) and (epid) Casr (-∕-))...

A 6-year-old male presented with a protruding hair emerging from a temporally located nodule on his left upper eyelid 5mm above the eyelid margin since birth. The lesion was excised and sent to histopathology. The features were consistent with congenital sebaceous trichofolliculoma, a rare hamartomatous skin lesion.

Hair follicle nevi are rare, benign, congenital hamartomas that usually occur in the distribution of the first brachial arch. Histopathologically, the distinction between hair follicle nevus, trichofolliculoma, and accessory tragus has recently come into question, and it may be that they are all on a spectrum of the same condition. We report the case of a 7-day-old boy who presented with a "tag"-like lesion on his midline chin that had been present since birth. Biopsy of the lesion proved it to be a hair follicle nevus...

Benign follicular tumors comprise a large and heterogeneous group of neoplasms that share a common histogenesis and display morphological features resembling one or several portions of the normal hair follicle, or recapitulate part of its embryological development. Most cases present it as clinically nondescript single lesions and essentially of dermatological relevance. Occasionally, however, these lesions be multiple and represent a cutaneous marker of complex syndromes associated with an increased risk of visceral neoplasms...

A single intraperitoneal injection of 50 or 75 mg/kg N-methyl-N-nitrosourea in male Sprague-Dawley rats at 4 weeks of age, dose-dependently resulted in cutaneous epithelial cysts and tumors of pilosebaceous origin. Cysts were composed of epidermal cysts or mixed epidermal and inner root sheath hybrid cysts. The majority of induced tumors were keratoacanthomas. A few tumors were trichofolliculomas, trichoblastomas, pilomatricomas, or sebaceous adenomas. All tumors were benign pilosebaceous tumors. Keratoacanthomas were crater-shaped tumors with thick infoldings of epithelium containing keratohyalin granules (epidermal lip) that abruptly changed to epithelium containing trichohyalin granules...