J Clin Aesthet Dermatol 2018 Mar 1;11(3):39-41. Epub 2018 Mar 1.

Dr. Segars is with NSU-COM/Largo Medical Center Dermatology Residency in Largo, Florida.

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. Read More

Indian J Dermatol Venereol Leprol 2018 Mar 1. Epub 2018 Mar 1.

Consultant Dermatologist, Sakhiya Skin Clinic, Surat, Gujarat, India.

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. Read More

Anticancer Res 2018 01;38(1):471-476

Dermatology Unit, Surgical, Medical and Dental Department of Morphological Sciences related to Transplant, Oncology and Regenerative Medicine, University of Modena and Reggio Emilia, Modena, Italy.

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. Read More

Arch Pathol Lab Med 2017 Nov;141(11):1490-1502

From the Departments of Pathology (Drs Stanoszek, Wang, and Harms) and Dermatology (Dr Harms), University of Michigan Medical School, Ann Arbor. Drs Stanoszek and Wang contributed equally.

Context: - Basal cell carcinoma (BCC) is the most common human malignant neoplasm and is a frequently encountered diagnosis in dermatopathology. Although BCC may be locally destructive, it rarely metastasizes. Many diagnostic entities display morphologic and immunophenotypic overlap with BCC, including nonneoplastic processes, such as follicular induction over dermatofibroma; benign follicular tumors, such as trichoblastoma, trichoepithelioma, or basaloid follicular hamartoma; and malignant tumors, such as sebaceous carcinoma or Merkel cell carcinoma. Read More

J Dermatol 2017 Nov 10;44(11):e278-e279. Epub 2017 Jul 10.

Department of Dermatology, Severance Hospital, Cutaneous Biology Research Institute, Yonsei University College of Medicine, Seoul, Korea.

Pediatr Dermatol 2017 Jul 29;34(4):e196-e200. Epub 2017 Jun 29.

Department of Dermatology, Complejo Hospitalario Insular Materno Infantil de Gran Canaria, Las Palmas, Spain.

Basaloid follicular hamartoma (BFH) is a rare follicular malformation characterized by variable clinical presentations and identical histopathologic features. We present the cases of a 3-month-old boy and an 8-year-old boy with linear unilateral BFH. To the best of our knowledge, only 14 cases of linear unilateral BFH have been described in the English-language literature. Read More

Ann Dermatol 2017 Jun 11;29(3):371-373. Epub 2017 May 11.

Department of Dermatology, Ajou University School of Medicine, Suwon, Korea.

Dermatol Online J 2017 May 15;23(5). Epub 2017 May 15.

Division of Dermatology, Department of Medicine, National University Hospital, Singapore. ellie_

Basaloid follicular hamartoma (BFH) is a rare benign adnexal tumor with variable clinical presentation. We report a case of a 64-year-old man, who presented with an incidental finding of a 3mm hyperpigmented macule on his cheek. Dermoscopy revealed a structureless blue lesion. Read More

Fukuoka Igaku Zasshi 2016 08;107(8):155-60

We here describe a case of solitary basaloid follicular hamartoma (BFH) : the case developing in company with senile lentigo on the nose. BFH is a relatively rare benign follicular neoplasm of undetermined etiology. Histologically, the specimen consisted of small-sized squamoid or basaloid cells and follicular germ-like cells in the periphery of the tumor nests. Read More

Br J Dermatol 2016 Mar;174(3):e11

Al Haud Al Marsoud Dermatology Hospital, Cairo, Egypt.

J Cutan Pathol 2016 Mar 12;43(3):191-9. Epub 2015 Oct 12.

Department of Dermatopathology, Dermatologikum Hamburg, Hamburg, Germany.

Background: Cysts are very common in the routine of dermatopathology but follicular germinative (trichoblastic) differentiation in cysts is seen rarely. The presence of follicular germinative differentiation in a cyst alerts to consider the possibility of a basal cell carcinoma (BCC) arising in a cyst.

Methods: Five cystic lesions with zones of follicular germinative differentiation were collected. Read More

Postepy Dermatol Alergol 2015 Jun 15;32(3):221-4. Epub 2015 Jun 15.

Department of Dermatology, Sifa University, Izmir, Turkey. Head of the Department: Assist. Prof. Fatma Asli Hapa.

Ann Dermatol 2015 Apr 24;27(2):218-20. Epub 2015 Mar 24.

Department of Dermatology, Gangnam Severance Hospital, Cutaneous Biology Research Institute, Yonsei University College of Medicine, Seoul, Korea.

J Cutan Pathol 2014 Dec;41(12):916-21

Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.

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. Read More

Korean J Radiol 2014 Jul-Aug;15(4):534-7. Epub 2014 Jul 9.

Department of Radiology, Mersin University Faculty of Medicine, Mersin 33070, Turkey.

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. Read More

Am J Dermatopathol 2015 Mar;37(3):e37-40

*Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ; †Department of Dermatology, Dermatology Cosmetic and Laser Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA; ‡Department of Medicine-Division of Dermatology, UC San Diego, San Diego, CA; §Department of Dermatology, UC Irvine, Irvine, CA; ¶RBGB Dermatology, Santa Ana, CA; and ‖Laguna Pathology Medical Group, Laguna Beach, CA.

Basaloid follicular hamartoma (BFH) is a rare, generally benign lesion of importance because of its clinical and histopathological similarity to infundibulocystic basal cell carcinoma. Autosomal dominant generalized BFH syndrome is 1 of the 5 clinical forms of BFH that has been described in the literature. We report a case of BFH syndrome in a 47-year-old Hispanic female who presented with an increasing number of small 1- to 2-mm tan to brown smooth facial papules, few palmar pits, and cobblestoning of the tongue. Read More

Clin Exp Dermatol 2013 Dec;38(8):862-5

Department of Dermatology, Chang Gung Memorial Hospital, Keelung, Taiwan; Chang Gung University College of Medicine, Taoyuan, Taiwan.

Happle-Tinschert syndrome (HTS) is a rare syndrome characterized by segmentally arranged basaloid follicular hamartomas (BFH) associated with ipsilateral osseous, dental and cerebral abnormalities. Happle and Tinschert first reported this disorder in 2008, and three cases with similar presentations have since been reported. We report another case, that of a 40-year-old man, presenting with the characteristic clinical features of HTS. Read More

Ophthal Plast Reconstr Surg 2012 Sep-Oct;28(5):e127-30

David G Cogan Laboratory of Ophthalmic Pathology, Massachusetts Eye and Ear Infirmary and Harvard Medical School, Boston, Massachusetts 02114 , USA.

An 86-year-old woman slowly developed a solitary 0.3 3 0.2-cm papule on the left lower eyelid. Read More

Dermatology 2012 9;224(2):97-100. Epub 2012 Mar 9.

Department of Internal Medicine, Oldness and Nephrologic Diseases, Dermatology, University of Bologna, Bologna, Italy.

Background: Focal dermal hypoplasia (FDH) or Goltz syndrome is a rare genetic multisystem disorder characterized by hypoplasia of ectodermally and mesodermally derived tissues. No cases of development of basal cell carcinomas in patients affected by FDH have previously been reported.

Methods: We followed a 38-year-old woman with FDH who developed, within a period of 3 years, 14 atypical pigmented lesions. Read More

Kaohsiung J Med Sci 2012 Jan 11;28(1):57-60. Epub 2011 Dec 11.

Department of Pathology and Laboratory Medicine, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan.

Basaloid follicular hamartoma (BFH) is a rare, benign, skin adnexal tumor. Several clinical patterns have been reported, but they all share the same histopathological features. BFH may be hereditary or nonhereditary and can be accompanied by systemic diseases. Read More

J Am Acad Dermatol 2011 Jul;65(1):e17-9

J Clin Invest 2011 May 25;121(5):1768-81. Epub 2011 Apr 25.

Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, USA.

Uncontrolled Hedgehog (Hh) signaling leads to the development of basal cell carcinoma (BCC), the most common human cancer, but the cell of origin for BCC is unclear. While Hh pathway dysregulation is common to essentially all BCCs, there exist multiple histological subtypes, including superficial and nodular variants, raising the possibility that morphologically distinct BCCs may arise from different cellular compartments in skin. Here we have shown that induction of a major mediator of Hh signaling, GLI2 activator (GLI2ΔN), selectively in stem cells of resting hair follicles in mice, induced nodular BCC development from a small subset of cells in the lower bulge and secondary hair germ compartments. Read More

Actas Dermosifiliogr 2011 Apr;102(3):233-5

Pediatr Dermatol 2011 Sep-Oct;28(5):555-60. Epub 2010 Nov 9.

Section of Dermatology, Department of Surgical Sciences, University of Parma, Parma, Italy.

The lines of Blaschko are a cutaneous pattern of mosaicism present in a variety of skin disorders. Developmental abnormalities affecting other tissues derived from the embryonic ectoderm and mesoderm are sometimes associated. Here, we describe a 5-year-old boy with basaloid follicular hamartoma affecting the left side of the body in linear multiple bands, following Blaschko lines. Read More

Nat Genet 2010 Oct 26;42(10):910-4. Epub 2010 Sep 26.

Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA.

Basaloid skin tumors, including basal cell carcinoma (BCC) and basaloid follicular hamartoma, are associated with aberrant Hedgehog (Hh) signaling and, in the case of BCC, an expanding set of genetic variants including keratin 5 (encoded by KRT5), an intermediate filament-forming protein. We here show that genetic ablation of keratin 17 (Krt17) protein, which is induced in basaloid skin tumors and co-polymerizes with Krt5 in vivo, delays basaloid follicular hamartoma tumor initiation and growth in mice with constitutive Hh signaling in epidermis. This delay is preceded by a reduced inflammation and a polarization of inflammatory cytokines from a Th1- and Th17-dominated profile to a Th2-dominated profile. Read More

Dermatology 2010 19;221(4):289-91. Epub 2010 Aug 19.

Department of Dermatology, Inselspital, University of Berne, Berne, Switzerland.

A 23-year-old man with a typical trichilemmal cyst nevus is reported. This recently described disorder is sufficiently characteristic to differentiate it from sebaceous nevus, nevus comedonicus, porokeratotic eccrine nevus, nevus corniculatus, follicular basaloid hamartoma, Munro's nevus and Gardner's syndrome. Read More

Arch Pathol Lab Med 2010 Aug;134(8):1215-9

Department of Pathology and Cell Biology, University of South Florida, Palmetto, FL 34221, USA.

Basaloid follicular hamartoma is a benign lesion of important consideration because it can be mistaken both clinically and histologically for basal cell carcinoma. The formation of basaloid follicular hamartoma has been linked to a mutation in the patched gene, which is part of the same pathway implicated in nevoid basal cell carcinoma syndrome. While these hamartomas are considered benign lesions, malignant growths have been reported to arise within them, which raises the question, "Is basaloid follicular hamartoma a premalignant lesion?" Correct identification allows for periodic monitoring for malignant transformation, while sparing patients unnecessary surgery. Read More

Ann Dermatol 2010 May 18;22(2):229-31. Epub 2010 May 18.

Department of Dermatology, Myongji Hospital, Kwandong University College of Medicine, Goyang, Korea.

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. Read More

Int J Dermatol 2010 Apr;49(4):443-7

Dermatology Department of Southwest Hospital, Third Military Medical University, Chongqing 400038, China.

Am J Dermatopathol 2009 Dec;31(8):819-27

Department of Pathology, Charles University Medical Faculty Hospital, Pilsen, Czech Republic.

We report a patient with multiple trichoepitheliomas whose biopsy material also demonstrated a range of other neoplasms with follicular differentiation, including small nodular trichoblastoma, small nodular basal cell carcinoma (BCC), and areas resembling infundibulocystic BCC/basaloid follicular hamartoma. These were all intimately associated with otherwise typical trichoepitheliomas that dominated the microscopic appearances. Peripheral blood and tumor tissues of the patient and his 2 daughters, who apparently had a milder phenotype, were studied for alterations in the CYLD and PTCH genes, but mutations or loss of heterozygosity was not found in either gene. Read More

J Cutan Pathol 2009 May 30;36(5):603; author reply 604. Epub 2009 Mar 30.

J Med Case Rep 2009 Feb 9;3:52. Epub 2009 Feb 9.

Molecular Genetics Laboratory, College of Medicine, King Saud University, Riyadh, Saudi Arabia.

Introduction: Nevoid basal cell carcinoma syndrome is a rare autosomal dominant disorder characterized by numerous basal cell carcinomas, odontogenic keratocysts of the jaws and developmental defects. The disorder results from mutations in the PTCH1 gene.

Case Presentation: A 15-year-old boy presented to our dental clinic with multiple jaw cysts. Read More

Nat Genet 2008 Sep;40(9):1130-5

Department of Dermatology and Comprehensive Cancer Center, University of Michigan Medical School, 1500 East Medical Center Drive, Ann Arbor, Michigan 48109, USA.

Constitutive Hedgehog (Hh) signaling underlies several human tumors, including basal cell carcinoma (BCC) and basaloid follicular hamartoma in skin. Intriguingly, superficial BCCs arise as de novo epithelial buds resembling embryonic hair germs, collections of epidermal cells whose development is regulated by canonical Wnt/beta-catenin signaling. Similar to embryonic hair germs, human BCC buds showed increased levels of cytoplasmic and nuclear beta-catenin and expressed early hair follicle lineage markers. Read More

Dermatology 2009 13;218(3):221-5. Epub 2008 Nov 13.

Department of Dermatology, University Hospital Basel, Basel, Switzerland.

Recently, Happle and Tinschert [Acta Derm Venereol 2008;88:382-387] described the case of a multisystem birth defect with segmentally arranged basaloid follicular hamartomas associated with extracutaneous defects in the form of short leg, polydactyly and hypoplastic teeth. The authors presented a comprehensive overview of 8 similar cases reported under various designations, and provided evidence that this syndrome includes various additional defects of the bones, teeth and brain. Here, a further typical case is reported, and it is emphasized that this phenotype should no longer be categorized as 'basal cell nevus syndrome', and thus be confused with the nevoid basal cell carcinoma syndrome of Gorlin [Cancer 1965;18:89-104]. Read More

Acta Derm Venereol 2008 ;88(4):382-7

Department of Dermatology, Philipp University of Marburg, Marburg, Germany.

A 39-year-old man presented with multiple basaloid follicular hamartomas involving the right side of his body in a systematized pattern following Blaschko's lines. His right leg was 22.5 cm shorter than the left, and rudimentary pre-axial polydactyly was noted on the left hand and the right foot. Read More

Dermatol Online J 2008 Apr 15;14(4):14. Epub 2008 Apr 15.

Department of Dermatology, Baylor College of Medicine, Houston, TX, USA.

Basaloid follicular hamartoma is a rare but benign adnexal neoplasm that can simulate basal cell carcinoma. Both sporadic and familial variants have been described. We illustrate a family cluster of this unusual entity which presented as milia-like or hyperpigmented papules. Read More

J Cutan Pathol 2008 May;35(5):477-83

Department of Dermatology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.

Generalized basaloid follicular hamartoma syndrome (GBFHS) is a rare, recently-described, autosomal-dominantly inherited disorder that presents with disseminated milia, palmoplantar pitting, hypotrichosis and basaloid follicular hamartomas (BFH). BFH is a benign adnexal tumor that resembles basal cell carcinoma (BCC). In this study, we report two cases of GBFHS and stain BFH, a vellus hair hamartoma (VHH) and a neurofollicular hamartoma (NH) with CD34, bcl-2 and CD10 to characterize and compare the staining patterns of these follicular tumors. Read More

Clin Exp Dermatol 2008 Jul 28;33(4):429-32. Epub 2008 Feb 28.

Department of Dermatology, Hospital del Mar IMAS, Barcelona, Spain.

Mosaicisms are characterized by genetic or functional differences between > or = 2 cell lines in one person, derived from a single zygote. Of the various clinical patterns of cutaneous mosaicism, linear lesions following Blaschko's lines are probably the most commonly encountered, Several cases of multiple basal cell carcinomas or basaloid hamartomatous lesions distributed in a segmentary distribution and following Blaschko's lines have been described. The various terms of 'linear unilateral basal cell naevus with comedones', 'linear unilateral basaloid follicular hamartoma', 'linear unilateral basal cell naevus', and 'basal-cell and linear unilateral adnexal hamartoma' have been used to define this apparently heterogeneous group of disorders. Read More

J Cutan Pathol 2007 Dec;34 Suppl 1:14-7

Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.

A 2-year-old girl presented with ulnar-sided duplication of the left thumb distal to the interphalangeal joint and syndactyly of the first web space. She also had several asymptomatic pink-tan cutaneous papules, involving the first and second ray of the left hand and wrist, clinically resembling a linear epidermal nevus. Microscopically, the papules were composed of well-circumscribed aggregates of basaloid epithelium within the dermis. Read More

Am J Dermatopathol 2007 Oct;29(5):462-6

University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.

Nevus sebaceus of Jadassohn is a hamartoma of multiple skin structures. Many neoplasms have been reported to arise in association with nevus sebaceus, most commonly trichoblastoma/basal cell carcinoma and syringocystadenoma papilliferum. We report a case of a 66-year-old woman with an adenocarcinoma as well as multiple neoplastic proliferations arising in a long standing nevus sebaceus on the scalp, with subsequent occipital neck metastatic disease. Read More

Dermatol Surg 2007 Sep;33(9):1130-5

Department of Dermatology and Cutaneous Biology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, USA.

Cutis 2007 Feb;79(2):154; author reply 155-6

Am J Dermatopathol 2007 Feb;29(1):92-5

Department of Anatomical Pathology, Service of Dermatology, Marqués de Valdecilla University Hospital, University of Cantabria, Santander, Spain.

Melanocytic nevi have been associated with epidermal hyperplasia, adnexal hyperplasia with follicular and sebaceous differentiation, cysts, and tumors of epidermal or adnexal origin. We report a combined cutaneous hamartoma in a 29-year-old woman that comprised a trichoadenoma within an intradermal melanocytic nevus. Clinical diagnosis was a malignant transformation of a melanocytic nevus. Read More

J Cutan Pathol 2007 Jan;34(1):65-70

Department of Dermatopathology, Laboratory Medicine Consultants, Las Vegas, NV 89109-2201, USA.

Background: Linear unilateral basal cell nevus represents a linear collection of macules and papules histologically similar to basal cell carcinoma but with benign clinical behavior. We describe a patient who initially presented at the age of 6 months with a unilateral linear basal cell nevus on the right flank. The differential diagnosis included the nevoid basal cell carcinoma syndrome. Read More

J Cutan Pathol 2007 Jan;34(1):39-43

Department of Pathology, University of British Columbia, British Columbia, Canada.

Background: Fibrous hamartoma of infancy (FHI) is a fast growing soft tissue tumor that usually arises in the first 2 years of life. The histology of the lesion has been well described. Few studies, however, have looked at changes in the overlying skin and its appendages. Read More

Cutis 2006 Jul;78(1):42-6

University of Pittsburgh Medical Center, Pennsylvania, USA.

Basaloid follicular hamartoma syndrome (BFHS) is a rare adnexal tumor genodermatosis. We present a case of hereditary BFHS and review the literature concerning the clinical and histologic features of this entity. Read More

J Med Genet 2005 Nov;42(11):811-9

Department of Dermatology, Columbia University Medical Center, New York, USA.

In the past decade the molecular basis of many inherited syndromes has been unravelled. This article reviews the clinical and genetic aspects of inherited syndromes that are characterised by skin appendage neoplasms, including Cowden syndrome, Birt-Hogg-Dube syndrome, naevoid basal cell carcinoma syndrome, generalised basaloid follicular hamartoma syndrome, Bazex syndrome, Brooke-Spiegler syndrome, familial cylindromatosis, multiple familial trichoepitheliomas, and Muir-Torre syndrome. Read More

Int J Dermatol 2005 May;44(5):361-5

Dermatology Department, Faculty of Medicine, Cairo University, Cairo, Egypt.

Basaloid follicular hamartoma (BFH) is a unique benign follicular hamartoma characterized by variable clinical presentations, identical histologic features and possible associations with numerous disorders. Basaloid follicular hamartoma may be hereditary or acquired. Hereditary cases may be either generalized or unilateral nevoid. Read More

Clin Exp Dermatol 2005 Jan;30(1):30-4

Department of Dermatology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Korea.

We report a 5-year-old girl with localized basaloid follicular hamartoma. The lesion consisted of a linear, hypopigmented, atrophic patch on the right lateral side of nose. Of great interest is that the linear distribution of lesion may follow the Blaschko's line of the face. Read More

Arch Dermatol 2005 Jan;141(1):60-7

Department of Dermatology, Roswell Park Cancer Institute, State University of New York at Buffalo, Buffalo, NY 14263, USA.

Objective: To report the use of wide-area 5-aminolevulinic acid photodynamic therapy to treat numerous basal cell carcinomas (BCCs) and basaloid follicular hamartomas (BFHs).

Design: Report of cases.

Setting: Roswell Park Cancer Institute. Read More