Follicular Basaloid Hamartoma and Associated Cutaneous Tumors: Clinical, Histopathological and Dermoscopic Aspects.

Background: Basaloid follicular hamartoma is an uncommun benign neoplasm of the hair follicule. The linear form of basaloid follicular hamartoma can be associated with basal cell carcinoma.OBJECTIVE: We report a case of a patient with multiple basal cell carcinomas developing on a congenital lesion allowing the diagnosis of basaloid follicular hamartoma on histopathology. Methods: Each lesion was evaluated by two dermatologists. All biopsy specimens were routinely stained with hematoxylin-eosin. Results: A 76 year-old-man consulted our dermatology departement for erythematous papules spread over the left lower limb. The lesion had been evolving since birth with flesh-colored to pinkish papules following Blaschko's lines from the root of the thigh to the foot. Three months before consultation, the papules increased in size leading to nodules with sometimes an ulcerated center. Dermoscopy under polarized mode displayed for ulcerated lesions (A) yellow-brownish crusts and ulceration surrounded by blue-grey ovoid nests, subtle short white streaks, brown dots and linear/arborising vessels. For nodular lesions (B), dermoscopic features are white pinkish hue, dotted and linear vessels, brown dots, blue-grey structureless areas and white prominent shiny streaks. There were some more erythematous inflamed and eroded areas in the background with a reversed honeycomb white network on dermoscopy (C), polymorphous vessels, whitish scales, ulcerations and milia-like cysts. The background lesion showed varied dermoscopic structures on a flesh colored slightly pinkish bottom (D). Histolopathology concluded for lesions A to an infiltrating and nodular basal cell carcinoma, (B) and (C) to fibroepithelioma of Pinkus and (D) to basaloid follicular hamartoma. Conclusion: Several case reports have documented dermoscopic features of a solitary basaloid follicular hamartoma. However, further studies are required to specify any reproducible features.

Basaloid follicular hamartoma syndrome: acquired sporadic variant with hypothyroidism, hypohidrosis and alopecia, a rare case.

Basaloid follicular hamartoma is a rare benign malformation of hair follicles, characterised clinically as generalised or localised multiple brown papules mostly on face, scalp and trunk. It may be congenital or acquired with or without any associated disease. Histologically it is composed of epithelial proliferation of basaloid cells with radial disposition enclosed in a fibrous stroma. It is of important consideration because it can be mistaken for basal cell carcinoma both clinically and histologically. Here we report the case of a 51-year-old female with acquired, generalised basaloid follicular hamartomas associated with alopecia, hypothyroidism and hypohidrosis which is an extremely rare disease.

Happle-Tinschert syndrome variable phenotype as part of the mosaic hedgehog spectrum: Report of three cases.

Happle-Tinschert syndrome is a rare genodermatosis caused by a postzygotic mutation in SMO gene. The most recognized clinical findings include segmentally arranged basaloid follicular hamartomas, nevoid hypertrichosis, linear atrophoderma, and hypopigmentation or hyperpigmentation following Blaschko lines associated with osseous, dental, and cerebral alterations. We report three additional cases, two of which lacked the pathognomonic basaloid follicular hamartomas, with genetic confirmation and detailed clinical characterization and describe new cutaneous features of this infrequent syndrome.

"Kissing" basaloid follicular hamartomas of the eyelid.

Basaloid follicular hamartomas (BFHs) are rare, benign, cutaneous adnexal tumors characterized by branching cords and anastomosing strands of basaloid cells in a loose, fibrous stroma. BFHs exhibit variable clinical presentations although they are commonly observed as skin-colored papules and are diagnosed based on histopathological features. Common systemic diseases associated with BFH include alopecia, myasthenia gravis, and palmoplantar pitting. BFH of the eyelid is extremely rare with only five cases reported in the literature to date. Congenital "kissing" lesions have only previously been reported with nevi. Here, we present a novel case of congenital "kissing" BFH of the right upper and right lower eyelid, and histopathological examination revealed intradermal nodules of basaloid cells forming reticulated strands, pseudohorn cysts, mucinous stroma, and palisading with CD34 and Bcl-2 expression in the stromal fibroblasts and periphery, respectively.

Basaloid Follicular Hamartoma of the Eyelid: A Case Report and Literature Review about an Unusual Lesion in the Ocular Region.

Basaloid follicular hamartoma (BFH) is a normally benign, uncommon, malformative lesion involving the hair follicles, which usually poses challenges in the differential diagnosis with other benign and malignant tumours, especially basal cell carcinoma, due to significant clinical and morphological overlap. Here, we report the case of a 53-year-old male who presented with a mass in the upper left eyelid evolving for one year. The patient had a previous history of total colectomy and an abdominal desmoid tumour within the context of Familial Adenomatous Polyposis (FAP), with a documented germline mutation in the Adenomatous Polyposis Coli (APC) gene. The eyelid lesion was biopsied and the histological analysis of the three small tissue fragments received revealed fragments with cutaneous-conjunctival lining displaying a subepithelial proliferation of basaloid nests with peripheral palisading, compatible with primitive hair follicles. There were images of anastomosis between different basaloid nests, which had their connection to the epithelial lining preserved. The stroma had high cellularity and sometimes primitive mesenchymal papillae were evident. Pleomorphism was absent, mitotic figures were barely identified, and no necrosis was seen. The basaloid nests did not have epithelial-stromal retraction nor mucin deposits. A diagnosis of BFH was proposed, which was later confirmed after surgical excision of the whole eyelid lesion. No evidence of carcinoma was present. This case illustrates the main features of the rare benign eyelid BFH. The standard medical or surgical approach of these lesions remains to be firmly established. Nearly nine months after surgical excision our patient remains well without signs of disease recurrence.

Basaloid follicular hamartoma of the eyelid in a pediatric patient.

PURPOSE: We report a case a pediatric patient with an eyelid lesion found to be a basaloid follicular hamartoma. OBSERVATIONS: A six-year-old female with juvenile diabetes who presented with a benign eyelid lesion harboring an aberrant eyelash. CONCLUSIONS AND IMPORTANCE: Basaloid follicular hamartoma is a rare benign neoplasm arising from hair follicles. These lesions can resemble basal cell carcinomas and require complete excision.

Happle-Tinschert Syndrome: A Case Report of Unilateral Segmentally Arranged Basaloid Follicular Hamartoma with Scoliosis and Review of Literature.

Happle-Tinschert syndrome is a rare disease characterized by unilateral, segmentally arranged basaloid follicular hamartoma (BFH) with osseous, dental, and cerebral anomalies. Although BFH has been demonstrated to be associated with mutations in the patched gene, the genetic basis for Happle-Tinschert syndrome is still unknown. We describe a case of Happle-Tinschert syndrome in a 26-year-old female. The patient presented with unilateral skin color change to brownish papules and atrophoderma following the development of Blaschko's lines, plantar pitting, and nail dystrophy on the right side of the body. She also had scoliosis, hemihypotrophy, and dental anomalies. The skin lesions were histologically confirmed as BFHs. Next-generation sequencing of the patient's genomic DNA obtained from a peripheral blood sample identified no pathogenic mutation. This case illustrates the characteristic clinical features of Happle-Tinschert syndrome. Thus far, 14 cases of Happle-Tinschert syndrome have been reported, and we report another case of this syndrome.

Clinicopathological and Dermoscopic Features in a Case of Linear and Unilateral Basaloid Follicular Hamartoma.

Linear and unilateral basaloid follicular hamartoma (BFH) is a rare disease that manifests with papules and plaques with distribution along lines of Blaschko. It runs a benign course but with the risk of basal cell carcinoma (BCC) in long term course. BCC can be differentiated from BFH with histopathology and immunohistochemistry. Dermoscopic features of BCC are well studied. Dermoscopic features of BFH are not yet described in literature in detail probably due to rarity of the disease. Here, we present a case of extensive linear and unilateral BFH with its clinicohistopathological and dermoscopic features. The lesions were extensive to involve scalp, face, neck, upper, and lower trunk. Dermoscopy revealed features similar to that of BCC including brown-grey globules and dots, in focus dots, brown linear and arciform structures, crown vessels, short fine telangiectasias, spoke wheel like structures without central dark point, white structureless areas with telangiectasias and keratotic plug. Other dermoscopic features of BCC like arborizing vessels, blue-grey ovoid nests, maple leaf-like areas, concentric structures, ulcerations, erosions and white streaks were absent in this case.

[Histopathological study of basaloid follicular hamartoma]. / Hamartome folliculaire basaloïde : étude anatomoclinique.

INTRODUCTION: Basaloid follicular hamartoma (BFH) is a rare tumor first described in 1985. It bears clinical and histologic similarities with basal cell carcinoma (BCC), in particular the so-called infundibulocystic form. We performed a single-center clinicopathological study of a series of typical cases of this entity that is occasionally difficult to diagnose. MATERIALS AND METHODS: All cases of BFH seen at the Dermatopathology Laboratory of Strasbourg University Hospital were included and analyzed by means of HE staining and Ber-EP4 and PHLDA1 immunolabelling. Diagnosis was made in the event of basaloid proliferation with anastomosing cords developed from a hair follicle. Clinical data were collected from clinical files. RESULTS: We identified 15 cases in 13 patients of mean age 44.8 years (range: 4 to 90) and the sex-ratio was 5/8. Lesions consisted of flesh-colored papules measuring 0.3 to 1.2cm in diameter, without any preferential site. Three patients had multiple lesions consisting of several coalescent papules on a breast for one, sparse papules on the back for another, and hundreds of linear unilateral BFHs, associated with osseous abnormalities, characteristic of Happle-Tinschert syndrome, for the third. All tumors were limited to the superficial and mid dermis, with a vertical orientation and connection to the epidermis in 14 of the 15 patients. In some cases, the outermost cells were basophilic while the central cells were eosinophilic. Peripheral palisading and clefting were frequently observed. Keratin cysts or sebaceous ducts were consistently present, indicating follicular differentiation. Ber-EP4+ cells were restricted to the periphery of the cords and PHLDA1 was weakly expressed. DISCUSSION: BFH is a rare entity that must be differentiated from BCC. It presents as solitary or multiple lesions, either grouped in plaques or with a generalized or linear unilateral distribution. Generalized BFH may be associated with autoimmune diseases and linear unilateral BFH with osseous, dental and cerebral abnormalities in Happle-Tinschert syndrome. It is important to distinguish BFH from BCC to avoid inappropriate aggressive treatment.

Localized unilateral basaloid follicular hamartoma along Blaschko's lines on face.

Basaloid follicular hamartoma (BFH) is a rare hamartoma of hair follicle. Clinical presentations may vary but are united by the same histopathological features in the form of folliculocentric basaloid or squamoid cell proliferation in the superficial dermis, which represents malformed and distorted hair follicles. It is important to recognize this entity as its simulant is basal cell carcinoma, a low-grade malignancy. Here, we report a case of localized unilateral BFH in a Blaschkoid distribution on the face of a 14-year-old female.

Cutaneous inflammation as a marker of malignant transformation in a patient with linear unilateral basaloid follicular hamartoma.

Basaloid follicular hamartoma is a rare, benign and superficial malformation of hair follicles, characterized histologically by epithelial proliferation of basaloid cells with radial disposition. It can be mistaken for basal cell carcinoma. Even though these hamartomas are considered benign lesions, malignant transformation has rarely been reported. We report the case of a 45-year-old healthy woman, with linear, unilateral basaloid follicular hamartoma which developed inflamed papules histologically suggestive of basal cell carcinoma. We believe that identification of local inflammation could be a clinical clue to guide us towards a malignant transformation of basaloid follicular hamartoma.

Generalized basaloid follicular hamartoma syndrome versus Gorlin syndrome: A diagnostic challenge.

Basaloid follicular hamartoma is a relatively rare benign neoplasm of follicular origin that can be mistaken histologically for basal cell carcinoma, but hereditary forms of basaloid follicular hamartoma are associated with nevoid basal cell carcinoma syndrome, or Gorlin syndrome. The pathophysiology of basaloid follicular hamartoma development involves mutations in the patched gene, which is also causative in nevoid basal cell carcinoma syndrome. We present a mother and daughter with basaloid follicular hamartomas, with genetic testing confirming patched gene mutation in the daughter.

Basaloid Follicular Hamartoma: A Case Report and a Novel Cosmetic Treatment.

Introduction: Basaloid follicular hamartoma (BFH) is a rare, benign neoplasm of the hair follicle, characterized by multiple brown papules involving the face, scalp, and trunk. It is described by multiple clinical forms, and can present as localized or generalized. Diagnosis is made histologically via biopsy, which is important in order to distinguish BFH from basal cell carcinoma (BCC) or other malignant epithelial neoplasms. Correct diagnosis allows for the avoidance of unnecessary surgeries to remove benign lesions. While benign, lesions can be cosmetically unacceptable. Case Report: A 68-year-old man with a two-year history of brown, homogenous papules on his face presented to discuss treatment options. A physical examination revealed hundreds of dark brown, 1- to 3mm verrucous papules distributed throughout the face. Two punch biopsies revealed histologic features consistent with BFH. Discussion: BFHs classically present with multiple 1- to 2mm tan-to-brown-colored papules distributed on the face, scalp, neck, axilla, trunk, and pubic area. Differential diagnoses can include nevus sebaceous, lichen striatus, linear epidermal nevus, and basal cell nevus. BFH arises from a mutation in the patch gene, the same gene thought to cause nevoid BCC syndrome. Histologic examination of BFH lesions is essential to diagnosis. No standard of care exists for BFH; treatment options remain limited. This patient was treated with three rounds of pulsed dye laser (PDL) therapy and showed marked improvement in the treated areas. The authors propose PDL to be a safe, effective, and novel cosmetic treatment for BFH and potentially other adnexal tumors.

PTCH1 Germline Mutations and the Basaloid Follicular Hamartoma Values in the Tumor Spectrum of Basal Cell Carcinoma Syndrome (NBCCS).

BACKGROUND/AIM: Nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominantly inherited disorder characterized by multiple basal cell carcinomas (BCC), odontogenic tumors and various skeletal anomalies. Basaloid follicular hamartomas (BFHs) constitute rare neoplasms that can be detected in sporadic and familial settings as in the Basaloid Follicular Hamartoma Syndrome (BFHS). Although BFHS shares clinical, histopathological and genetic overlapping with the NBCCS, they are still considered two distinctive entities. The aim of our single-institution study was the analysis of a cohort of PTCH1-mutated patients in order to define clinical and biomolecular relationship between NBCCS and BFHs. MATERIALS AND METHODS: In our study we evaluated PTCH1 gene-carrier probands affected by NBCCS to detect the incidence of BFHs and their correlation with this rare syndrome. RESULTS: Among probands we recognized 4 patients with BFHs. We found 15 germline PTCH1 mutations, uniformly distributed across the PTCH1 gene. Six of them had familial history of NBCCS, two of them were novel and have not been described previously. CONCLUSION: NBCCS and BFHS may be the same genetic entity and not two distinctive syndromes. The inclusion of BFH in the NBCCS cutaneous tumor spectrum might be useful for the recognition of misdiagnosed NBCCS cases that could benefit from tailored surveillance strategies.

Cytokeratin 20 expression in basaloid follicular hamartoma and infundibulocystic basal cell carcinoma.

BACKGROUND: Tumors with similar or identical histopathologic features have been termed basaloid follicular hamartoma (BFH) or infundibulocystic basal cell carcinoma (BCC). BCC typically lacks immunoreactivity with cytokeratin 20 (CK20) and pleckstrin homology-like domain, family A, member 1 protein (PHLDA1). AIM: A series of BFH and infundibulocystic BCC were investigated to determine the pattern of CK20 and PHLDA1 labeling in these lesions. MATERIALS AND METHODS: Thirty-six samples of BFH (n = 14) and infundibulocystic BCC (n = 22) were collected. CK20 and PHLDA1 staining was performed and evaluated. RESULTS: All the lesions were small (average of 3 mm), well circumscribed, and composed of basaloid to squamoid cells arranged in islands resembling ramifying rootlets with interspersed horn cysts. CK20-positive cells were present in all 36 cases (average, 22/mm(2)), throughout the tumor, including deeper portions, irrespective of original diagnosis. Six of thirty cases (20%; 5 infundibulocystic BCC, 1 BFH) were focally PHLDA1 positive. CONCLUSIONS: Findings on hematoxylin and eosin staining and those of CK20 staining in BFH and infundibulocystic BCC were similar, and in most cases were indistinguishable. The CK20 labeling was similar to that of trichoepithelioma. The findings add a degree of support to the argument that BFH and infundibulocystic BCC represent the same lesion and, further, a benign one.

Happle-Tinschert syndrome: report of a case with hemimegalencephaly.

Happle-Tinschert syndrome is a disorder causing unilateral segmentally arranged basaloid follicular hamartomas of the skin associated with ipsilateral osseous, dental and cerebral abnormalities including tumors. Although a case with hemimegalencephaly was previously described, this is the first report of Happle-Tinschert syndrome with discrepant short left leg, ipsilateral skin lesions, hemimegalencephaly and frontal polymicrogyria.

Happle-Tinschert Syndrome: Report of a Case with Hemimegalencephaly

Happle-Tinschert syndrome is a disorder causing unilateral segmentally arranged basaloid follicular hamartomas of the skin associated with ipsilateral osseous, dental and cerebral abnormalities including tumors. Although a case with hemimegalencephaly was previously described, this is the first report of Happle-Tinschert syndrome with discrepant short left leg, ipsilateral skin lesions, hemimegalencephaly and frontal polymicrogyria.

A case of basaloid follicular hamartoma.

Basaloid follicular hamartoma (BFH), uncommon rare benign neoplasm connected to the adnexal structures, presents with multiple clinical manifestations that can develop into basal cell carcinoma. BFH may be congenital or acquired, and the congenital form can be further divided into the generalized and unilateral type, and the acquired form may present as localized and solitary lesions. Congenital, generalized BFH is associated with systemic diseases such as alopecia, cystic fibrosis, hypohidrosis, and myasthenia gravis. In contrast, sporadic cases are observed as unilateral or localized lesions. BFH shows thick cords and thin strands of anastomosing basaloid proliferations that arise from hair follicles and are enclosed by loose fibrous stroma. Here, we report a 70-year-old man with an acquired, solitary form of BFH.

A Case of Basaloid Follicular Hamartoma

Basaloid follicular hamartoma (BFH), uncommon rare benign neoplasm connected to the adnexal structures, presents with multiple clinical manifestations that can develop into basal cell carcinoma. BFH may be congenital or acquired, and the congenital form can be further divided into the generalized and unilateral type, and the acquired form may present as localized and solitary lesions. Congenital, generalized BFH is associated with systemic diseases such as alopecia, cystic fibrosis, hypohidrosis, and myasthenia gravis. In contrast, sporadic cases are observed as unilateral or localized lesions. BFH shows thick cords and thin strands of anastomosing basaloid proliferations that arise from hair follicles and are enclosed by loose fibrous stroma. Here, we report a 70-year-old man with an acquired, solitary form of BFH.

A Case of Familial Basaloid Follicular Hamartoma Syndrome / 대한피부과학회지

Basaloid follicular hamartoma is a benign adnexal tumor consisting of basaloid cells with follicular differentiation. It can present as a solitary lesion, multiple lesions, or an autosomal dominant inherited syndrome (basaloid follicular hamartoma syndrome). Basaloid follicular hamartoma syndrome is a rare adnexal tumor genodermatosis, which is characterized by autosomal dominant inheritance, histologically proven basaloid follicular hamartomas and associated findings including hypotrichosis, palmar/plantar pitting and hypohidrosis, etc. Herein, we report a case of 4-year-old girl with familial generalized basaloid follicular hamartoma syndrome.