Pediatric Dermatology Vol. 34 No. 4 e196–e200, 2017
Linear Unilateral Basaloid Follicular Hamartoma Following Blaschko’s Lines: Two Case Reports and Review of the Literature Esmeralda C. L opez Jimenez, M.D.,* Cristina Grau, M.D., Ph.D.,† Diana Islas Norris, M.D.,* T arsila Montenegro D amaso, M.D.,‡ Antoni Az on, M.D., Ph.D.,† and Leopoldo Borrego Hernando, M.D., Ph.D.* *Department of Dermatology, Complejo Hospitalario Insular Materno Infantil de Gran Canaria, Las Palmas, Spain, †Department of Dermatology, Hospital Universitari Sant Joan de Reus, Tarragona, Spain, ‡Department of Pathology, Complejo Hospitalario Insular Materno Infantil de Gran Canaria, Las Palmas, Spain
Abstract: 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.
Basaloid follicular hamartoma (BFH) is a rare follicular malformation with distinctive histopathologic patterns. A characteristic finding is the presence of branching cords and thin strands of undifferentiated anastomosing basaloid proliferations that arise from hair follicles and are embedded in a fibrous stroma (1–6), although basaloid follicular hamartomatous changes can be seen in a wide range of clinical situations: a congenital or acquired generalized type associated with systemic diseases, a localized linear and unilateral type, and a solitary plaque or nodular type (1–8). Carney (9) reported the first case of linear and unilateral BFH in 1952, calling it linear
unilateral basal-cell nevus with comedones. We present two cases of linear unilateral BFH.
CASE REPORTS Patient 1 A 3-month-old infant boy presented with unilateral skin lesions on the right side of his trunk, arm, forearm, and hand that had been present since birth. There was no family history of similar lesions. Physical examination showed multiple unilateral, linear hypopigmented papules and plaques following
Address correspondence to Esmeralda Carmen L opez Jimenez, M.D., Department of Dermatology, Complejo Hospitalario Insular Materno Infantil de Gran Canaria, Avenida Marıtima del Sur, S/N, 35016 Las Palmas de Gran Canaria, Las Palmas, Spain, or e-mail: [email protected]. DOI: 10.1111/pde.13185
e196
© 2017 Wiley Periodicals, Inc.
L opez Jimenez et al: Linear unilateral BFH
e197
Blaschko’s lines distributed over the right side of the trunk, right shoulder, arm, forearm, and hand (Fig. 1). Patient 2 An 8-year-old boy presented with a 4-year history of a persistent, asymptomatic, linear lesion on the left side of the chin. Family history was negative for similar lesions. Physical examination revealed linear hypopigmented papules following Blaschko’s lines from the left preauricular region to the left oral commissure (Fig. 2). Histopathologic examination of biopsy specimens taken from both cases revealed features specific for BFH. The papillary dermis contained branching cords and thin anastomosing strands of small basaloid cells embedded in loose fibrous stroma. In some areas, keratin cyst formations were seen inside the basaloid proliferations. Mitotic figures and cytologic atypia were absent (Figs. 3 and 4). DISCUSSION BFH is a follicular malformation that Brown et al (1) described for the first time in 1969. After the first case, similar histopathologic findings were described in different clinical settings. Mehregan and Baker (2) coined the term “basaloid follicular hamartoma” in 1985. Morohashi et al (3), based on ultrastructural and immunohistochemical studies, described BFH as an abortive growth of secondary hair germs with
Figure 2. Patient 2: linear hypopigmented papules following Blaschko’s lines on the left cheek. [Color figure can be viewed at wileyonlinelibrary.com]
Figure 3. Biopsy specimen from patient 1 reveals a multifocal proliferation of basaloid cells in the papillary dermis that form islands, branching cords, and thin strands. In some areas, keratin cyst formation is seen inside the basaloid proliferations. [Color figure can be viewed at wileyonlinelibrary.com]
Figure 1. Patient 1: linear hypopigmented papules and plaques following Blaschko’s lines over the right side of the chest, right shoulder, and right arm. [Color figure can be viewed at wileyonlinelibrary.com]
limited differentiation toward the upper follicular portion of the hair shaft. Changes in PTCH signaling pathways seem to contribute to the pathogenesis of BFH. Grachtchouk
e198 Pediatric Dermatology Vol. 34 No. 4 July/August 2017
Figure 4. Histopathologic examination of patient 2 demonstrates a folliculo-centered lesion composed of anastomosing strands and branching cords of basaloid cells embedded in a fibrous stroma. [Color figure can be viewed at wileyonlinelibrary.com]
et al (4) examined the expression of PTCH1 in a series of five human basal cell carcinomas (BCCs) and five BFHs. Expression of PTCH1 was detected in all BCC tumor cells and only in a fraction of cells constituting the BFH. Jih et al (5) studied the expression of PTCH1 in a representative lesion of BFH and other BCC lesions from two patients with familial BFH. In BCC, lesional cells demonstrated diffusely greater amounts of PTCH1 mRNA throughout the tumor, whereas in BFH, PTCH1 mRNA was overexpressed only in lesional cells that were in contact with the dermis. These results suggest that PTCH signaling pathways may be abnormal in BFH, but the degree of aberrant expression appears to be lower in BFH than in BCC, although additional studies such as gene expression profiling and genomic studies are necessary to better define the pathogenesis of BFH. BFH may manifest with different clinical presentations, such as a solitary lesion or as multiple lesions with a generalized or localized linear unilateral distribution. It may be a familial, congenital, or acquired condition. Solitary BFH was first described in 1992 as a smooth plaque or a papule appearing most commonly on the face or scalp (6). Several forms of
generalized BFH have been described (7): sporadic form—multiple BFHs without systemic disease; generalized acquired form—female patients with generalized BFHs associated with alopecia and autoimmune diseases, such as myasthenia gravis and systemic lupus erythematosus, in which the lesions are found mainly on the face and periorificial areas; generalized familial form—an autosomal dominant disease that may or may not be associated with hypotrichosis, hypohidrosis, and palmoplantar pitting and appears on the face and genital region; and generalized congenital form—generalized BFH associated with other ectodermal defects, such as hypotrichosis and punctate keratotic pits, on the palms and soles and with cystic fibrosis. An autosomal dominant generalized basaloid follicular hamartoma syndrome (GBFHS) has also been reported. Its salient features include congenital or early childhood presentation of BFH associated with milia, comedones, dermatosis papulosa nigra, and acrochordons. Another report of multiple BFH lesions present in a patient with acrochordons, seborrheic keratoses, and chondrosarcoma demonstrates that BFH can be associated with acrochordons and seborrheic keratoses outside the context of an inherited syndrome (5). The linear and unilateral type of BFH may be present at birth (8,10–15), as in our first patient; appear during childhood (2,6,14,16), as in our second patient; or develop during puberty (17,18). The most important clinical feature in this type of BFH is the unilateral and linear distribution of the lesions that in almost all patients might be associated with the lines of Blaschko (6,15,18). Lesions may be hypopigmented to darker macules, papules, or plaques with or without comedones (6,15,17). In contrast to generalized BFH, no association with myasthenia gravis or systemic lupus erythematous has been described, although one patient had Graves’ disease (2) and two had congenital dorsal scoliosis (8,11). In three patients, BCCs developed within the linear and unilateral type of BFH (8,12,17). A patient with linear and unilateral BFH with an unusual, extensive proliferation of trichoblastoma has also been reported (13). Moreover, it may occur in association with Happle–Tinschert syndrome, characterized by segmentally arranged BFHs associated with ipsilateral osseous, dental, and cerebral abnormalities (19). The histopathologic findings of BFH consist of multifocal islands and branching cords of basaloid epithelial cells in the papillary dermis, some of which are connected to the epidermis, and dilated hair
L opez Jimenez et al: Linear unilateral BFH
follicles. The formation of keratin cysts is common within the branching cords or lacelike networks of basaloid cells. Neither cellular atypia nor mitotic figures are seen in BFH (6,14,15,17). Immunohistochemistry can also be a useful tool in distinguishing BFH from BCC. The stroma of all BCCs is negative for CD34, whereas BFHs and other benign follicular tumors are CD34-positive. BCC is diffusely positive for BER-EP, whereas BFH is negative for BER-EP. BCC expresses androgen receptors; BFH does not. Ki-67-positive staining nuclei are numerous in BCC but few in BFH. BCL2-positive cells are scattered throughout the lobules and cords of BCC but are restricted to the periphery of the trabeculae in BFH. CK20-positive Merkel cells are more common in BFH and rarely occur in BCC (20).
e199
The clinical differential diagnosis of linear unilateral BFH includes other linear and unilateral dermatoses, such as linear trichoepithelioma, unilateral nevoid BCC syndrome, linear epidermal naevus, linear eccrine naevus, linear eccrine spiradenoma, linear poroma, and linear syringoma (15). The main histologic differential diagnosis includes infundibulocystic BCC, folliculocentric basaloid proliferation, and trichoepithelioma (6,11,15). CONCLUSION We present two cases of linear unilateral BFH. To the best of our knowledge, only 14 cases of linear unilateral BFH have been described in the English-language literature (Table 1). We emphasize the importance of long-term follow-up of these patients, paying attention
TABLE 1. Comparative Features of Reported Cases of Linear Unilateral Basaloid Follicular Hamartoma Sex
Age of onset
Age at diagnosis
Distribution
Skin lesions
1
Male
Since birth
69 yrs
Left side of head and body
Comedones and pearly to lightbrown papules
2
Female
Since birth
37 yrs
From left side of trunk to left leg
3
Male
Since birth
18 yrs
4
Female
Childhood
53 yrs
5
Female
Puberty
36 yrs
6
Male
Since birth
34 yrs
Right upper extremity, right side of trunk, right lower extremity Right upper back, arm, chest, breast, abdomen From left upper back to shoulder, down arm and chest Right side of neck
Skin-colored, erythematousviolaceous and brownish, papules and nodules Nodules, striaelike areas of atrophy and comedones
7
Female
Since birth
18 yrs
From right shoulder to right leg
8
Female
Childhood
13 yrs
9 10 11 12 13
Male Female Male Female Female
Childhood Since birth Since birth Childhood Childhood
7 yrs 6.5 yrs 24 yrs 5 yrs 5 yrs
14
Female
Puberty
26 yrs
Left side of chin and neck, left shoulder, left side of the chest Right shoulder Left side of trunk Left shoulder and arm Right side of nose Left side of nose, left retroauricular area, posterior neck Lower part of right cheek
Present patient 1
Male
Since birth
3 mos
Present patient 2
Male
Childhood
8 yrs
Patient
Right side of trunk, shoulder, arm, forearm, hand From left preauricular region to oral commissure
Associated diseases
Reference
Congenital dorsal scoliosis, basal cell carcinoma –
8
Congenital dorsal scoliosis Graves’ disease
11
Basal cell carcinoma
17
Flesh-to-yellow plaque composed of multiple coalescent papules Hyperpigmented, hyperkeratotic plaques and nodules Pigmented papules and skin tag –like lesions
Basal cell carcinoma
12
Trichoblastoma
13
–
14
Skin-colored and dark papules Flesh- to dark-colored papules Light-brown colored papules Hypopigmented atrophic patch Firm, hyperpigmented, grouped papules and comedones
– – – – –
14 14 15 6 16
Skin-colored pits and comedones Hypopigmented papules and plaques
–
18
Hypopigmented papules
–
Light brown plaques and papules Hypopigmented macules and plaques
–
10
2
e200 Pediatric Dermatology Vol. 34 No. 4 July/August 2017
to new growths or changes in the lesions of BFH to detect possible BCCs arising on BFHs. We also suggest that BFH should be included in the differential diagnosis of skin conditions following Blaschko’s lines. REFERENCES 1. Brown AC, Crounse RG, Winkelmann RK. Generalized hair-follicle hamartoma. Associated with alopecia, aminoaciduria, and myasthenia gravis. Arch Dermatol 1969;99:478–493. 2. Mehregan AH, Baker S. Basaloid follicular hamartoma: three cases with localized and systematized unilateral lesions. J Cutan Pathol 1985;12:55–65. 3. Morohashi M, Sakamoto F, Takenouchi T et al. A case of localized follicular hamartoma: an ultrastructural and immunohistochemical study. J Cutan Pathol 2000;27:191–198. 4. Grachtchouk V, Grachtchouk M, Lowe L et al. The magnitude of hedgehog signaling activity defines skin tumor phenotype. EMBO J 2003;22:2741–2751. 5. Jih DM, Shapiro M, James WD et al. Familial basaloid follicular hamartoma: lesional characterization and review of the literature. Am J Dermatopathol 2003;25:130–137. 6. Brownstein MH. Basaloid follicular hamartoma: solitary and multiple types. J Am Acad Dermatol 1992;27:237–240. 7. Huang SH, Hsiao TF, Lee CC. Basaloid follicular hamartoma: a case report and review of the literature. Kaohsiung J Med Sci 2012;28:57–60. 8. Lee MW, Choi JH, Moon KC et al. Linear basaloid follicular hamartoma on the Blaschko’s line of the face. Clin Exp Dermatol 2005;30:30–34. 9. Carney RG. Linear unilateral basal cell nevus with comedones. Arch Dermatol 1952;100:187–190.
10. Anderson TE, Best PV. Linear basal-cell naevus. Br J Dermatol 1962;74:20–23. 11. Bleiberg J, Brodkin RH. Linear unilateral basal cell nevus with comedones. Arch Dermatol 1969;100:187– 190. 12. Nelson BR, Johnson TM, Waldinger T et al. Basaloid follicular hamartoma: a histologic diagnosis with diverse clinical presentation. Arch Dermatol 1993;129: 915–917. 13. Kaiser A, Spence RJ, Parwani A et al. Basaloid follicular hamartoma with trichoblastomatous proliferations. J Cutan Med Surg 2003;7:395–398. 14. El-Darouti MA, Marzouk SA, Abdel-Halim MR et al. Basaloid follicular hamartoma. Int J Dermatol 2005;44:361–365. 15. Harman M, Inal€ oz HS, Akdeniz S et al. Congenital non-familial unilateral basaloid follicular hamartoma. J Eur Acad Dermatol Venereol 1999;13:210–213. 16. Kim TH, Oh SJ, Kim YC et al. Segmentally arranged hyperpigmented basaloid follicular hamartoma. Ann Dermatol 2015;27:218–220. 17. Jimenez-Acosta FJ, Redondo E, Baez O et al. Linear unilateral basaloid follicular hamartoma. J Am Acad Dermatol 1992;27:316–319. 18. ElBehairy S, Elbendary A, Moussa Z. Image gallery: linear unilateral basaloid follicular hamartoma: a unique presentation. Br J Dermatol 2016;174:e11. 19. Happle R, Tinschert S. Segmentally arranged basaloid follicular hamartomas with osseous, dental and cerebral anomalies: a distinct syndrome. Acta Derm Venereol 2008;88:382–387. 20. Gumaste P, Ortiz AE, Patel A et al. Generalized basaloid follicular hamartoma syndrome: a case report and review of the literature. Am J Dermatopathol 2015;37:e37–e40.
Linear Unilateral Basaloid Follicular Hamartoma Following Blaschko’s Lines: Two Case Reports and Review of the Literature Esmeralda C. L opez Jimenez, M.D.,* Cristina Grau, M.D., Ph.D.,† Diana Islas Norris, M.D.,* T arsila Montenegro D amaso, M.D.,‡ Antoni Az on, M.D., Ph.D.,† and Leopoldo Borrego Hernando, M.D., Ph.D.* *Department of Dermatology, Complejo Hospitalario Insular Materno Infantil de Gran Canaria, Las Palmas, Spain, †Department of Dermatology, Hospital Universitari Sant Joan de Reus, Tarragona, Spain, ‡Department of Pathology, Complejo Hospitalario Insular Materno Infantil de Gran Canaria, Las Palmas, Spain
Abstract: 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.
Basaloid follicular hamartoma (BFH) is a rare follicular malformation with distinctive histopathologic patterns. A characteristic finding is the presence of branching cords and thin strands of undifferentiated anastomosing basaloid proliferations that arise from hair follicles and are embedded in a fibrous stroma (1–6), although basaloid follicular hamartomatous changes can be seen in a wide range of clinical situations: a congenital or acquired generalized type associated with systemic diseases, a localized linear and unilateral type, and a solitary plaque or nodular type (1–8). Carney (9) reported the first case of linear and unilateral BFH in 1952, calling it linear
unilateral basal-cell nevus with comedones. We present two cases of linear unilateral BFH.
CASE REPORTS Patient 1 A 3-month-old infant boy presented with unilateral skin lesions on the right side of his trunk, arm, forearm, and hand that had been present since birth. There was no family history of similar lesions. Physical examination showed multiple unilateral, linear hypopigmented papules and plaques following
Address correspondence to Esmeralda Carmen L opez Jimenez, M.D., Department of Dermatology, Complejo Hospitalario Insular Materno Infantil de Gran Canaria, Avenida Marıtima del Sur, S/N, 35016 Las Palmas de Gran Canaria, Las Palmas, Spain, or e-mail: [email protected]. DOI: 10.1111/pde.13185
e196
© 2017 Wiley Periodicals, Inc.
L opez Jimenez et al: Linear unilateral BFH
e197
Blaschko’s lines distributed over the right side of the trunk, right shoulder, arm, forearm, and hand (Fig. 1). Patient 2 An 8-year-old boy presented with a 4-year history of a persistent, asymptomatic, linear lesion on the left side of the chin. Family history was negative for similar lesions. Physical examination revealed linear hypopigmented papules following Blaschko’s lines from the left preauricular region to the left oral commissure (Fig. 2). Histopathologic examination of biopsy specimens taken from both cases revealed features specific for BFH. The papillary dermis contained branching cords and thin anastomosing strands of small basaloid cells embedded in loose fibrous stroma. In some areas, keratin cyst formations were seen inside the basaloid proliferations. Mitotic figures and cytologic atypia were absent (Figs. 3 and 4). DISCUSSION BFH is a follicular malformation that Brown et al (1) described for the first time in 1969. After the first case, similar histopathologic findings were described in different clinical settings. Mehregan and Baker (2) coined the term “basaloid follicular hamartoma” in 1985. Morohashi et al (3), based on ultrastructural and immunohistochemical studies, described BFH as an abortive growth of secondary hair germs with
Figure 2. Patient 2: linear hypopigmented papules following Blaschko’s lines on the left cheek. [Color figure can be viewed at wileyonlinelibrary.com]
Figure 3. Biopsy specimen from patient 1 reveals a multifocal proliferation of basaloid cells in the papillary dermis that form islands, branching cords, and thin strands. In some areas, keratin cyst formation is seen inside the basaloid proliferations. [Color figure can be viewed at wileyonlinelibrary.com]
Figure 1. Patient 1: linear hypopigmented papules and plaques following Blaschko’s lines over the right side of the chest, right shoulder, and right arm. [Color figure can be viewed at wileyonlinelibrary.com]
limited differentiation toward the upper follicular portion of the hair shaft. Changes in PTCH signaling pathways seem to contribute to the pathogenesis of BFH. Grachtchouk
e198 Pediatric Dermatology Vol. 34 No. 4 July/August 2017
Figure 4. Histopathologic examination of patient 2 demonstrates a folliculo-centered lesion composed of anastomosing strands and branching cords of basaloid cells embedded in a fibrous stroma. [Color figure can be viewed at wileyonlinelibrary.com]
et al (4) examined the expression of PTCH1 in a series of five human basal cell carcinomas (BCCs) and five BFHs. Expression of PTCH1 was detected in all BCC tumor cells and only in a fraction of cells constituting the BFH. Jih et al (5) studied the expression of PTCH1 in a representative lesion of BFH and other BCC lesions from two patients with familial BFH. In BCC, lesional cells demonstrated diffusely greater amounts of PTCH1 mRNA throughout the tumor, whereas in BFH, PTCH1 mRNA was overexpressed only in lesional cells that were in contact with the dermis. These results suggest that PTCH signaling pathways may be abnormal in BFH, but the degree of aberrant expression appears to be lower in BFH than in BCC, although additional studies such as gene expression profiling and genomic studies are necessary to better define the pathogenesis of BFH. BFH may manifest with different clinical presentations, such as a solitary lesion or as multiple lesions with a generalized or localized linear unilateral distribution. It may be a familial, congenital, or acquired condition. Solitary BFH was first described in 1992 as a smooth plaque or a papule appearing most commonly on the face or scalp (6). Several forms of
generalized BFH have been described (7): sporadic form—multiple BFHs without systemic disease; generalized acquired form—female patients with generalized BFHs associated with alopecia and autoimmune diseases, such as myasthenia gravis and systemic lupus erythematosus, in which the lesions are found mainly on the face and periorificial areas; generalized familial form—an autosomal dominant disease that may or may not be associated with hypotrichosis, hypohidrosis, and palmoplantar pitting and appears on the face and genital region; and generalized congenital form—generalized BFH associated with other ectodermal defects, such as hypotrichosis and punctate keratotic pits, on the palms and soles and with cystic fibrosis. An autosomal dominant generalized basaloid follicular hamartoma syndrome (GBFHS) has also been reported. Its salient features include congenital or early childhood presentation of BFH associated with milia, comedones, dermatosis papulosa nigra, and acrochordons. Another report of multiple BFH lesions present in a patient with acrochordons, seborrheic keratoses, and chondrosarcoma demonstrates that BFH can be associated with acrochordons and seborrheic keratoses outside the context of an inherited syndrome (5). The linear and unilateral type of BFH may be present at birth (8,10–15), as in our first patient; appear during childhood (2,6,14,16), as in our second patient; or develop during puberty (17,18). The most important clinical feature in this type of BFH is the unilateral and linear distribution of the lesions that in almost all patients might be associated with the lines of Blaschko (6,15,18). Lesions may be hypopigmented to darker macules, papules, or plaques with or without comedones (6,15,17). In contrast to generalized BFH, no association with myasthenia gravis or systemic lupus erythematous has been described, although one patient had Graves’ disease (2) and two had congenital dorsal scoliosis (8,11). In three patients, BCCs developed within the linear and unilateral type of BFH (8,12,17). A patient with linear and unilateral BFH with an unusual, extensive proliferation of trichoblastoma has also been reported (13). Moreover, it may occur in association with Happle–Tinschert syndrome, characterized by segmentally arranged BFHs associated with ipsilateral osseous, dental, and cerebral abnormalities (19). The histopathologic findings of BFH consist of multifocal islands and branching cords of basaloid epithelial cells in the papillary dermis, some of which are connected to the epidermis, and dilated hair
L opez Jimenez et al: Linear unilateral BFH
follicles. The formation of keratin cysts is common within the branching cords or lacelike networks of basaloid cells. Neither cellular atypia nor mitotic figures are seen in BFH (6,14,15,17). Immunohistochemistry can also be a useful tool in distinguishing BFH from BCC. The stroma of all BCCs is negative for CD34, whereas BFHs and other benign follicular tumors are CD34-positive. BCC is diffusely positive for BER-EP, whereas BFH is negative for BER-EP. BCC expresses androgen receptors; BFH does not. Ki-67-positive staining nuclei are numerous in BCC but few in BFH. BCL2-positive cells are scattered throughout the lobules and cords of BCC but are restricted to the periphery of the trabeculae in BFH. CK20-positive Merkel cells are more common in BFH and rarely occur in BCC (20).
e199
The clinical differential diagnosis of linear unilateral BFH includes other linear and unilateral dermatoses, such as linear trichoepithelioma, unilateral nevoid BCC syndrome, linear epidermal naevus, linear eccrine naevus, linear eccrine spiradenoma, linear poroma, and linear syringoma (15). The main histologic differential diagnosis includes infundibulocystic BCC, folliculocentric basaloid proliferation, and trichoepithelioma (6,11,15). CONCLUSION We present two cases of linear unilateral BFH. To the best of our knowledge, only 14 cases of linear unilateral BFH have been described in the English-language literature (Table 1). We emphasize the importance of long-term follow-up of these patients, paying attention
TABLE 1. Comparative Features of Reported Cases of Linear Unilateral Basaloid Follicular Hamartoma Sex
Age of onset
Age at diagnosis
Distribution
Skin lesions
1
Male
Since birth
69 yrs
Left side of head and body
Comedones and pearly to lightbrown papules
2
Female
Since birth
37 yrs
From left side of trunk to left leg
3
Male
Since birth
18 yrs
4
Female
Childhood
53 yrs
5
Female
Puberty
36 yrs
6
Male
Since birth
34 yrs
Right upper extremity, right side of trunk, right lower extremity Right upper back, arm, chest, breast, abdomen From left upper back to shoulder, down arm and chest Right side of neck
Skin-colored, erythematousviolaceous and brownish, papules and nodules Nodules, striaelike areas of atrophy and comedones
7
Female
Since birth
18 yrs
From right shoulder to right leg
8
Female
Childhood
13 yrs
9 10 11 12 13
Male Female Male Female Female
Childhood Since birth Since birth Childhood Childhood
7 yrs 6.5 yrs 24 yrs 5 yrs 5 yrs
14
Female
Puberty
26 yrs
Left side of chin and neck, left shoulder, left side of the chest Right shoulder Left side of trunk Left shoulder and arm Right side of nose Left side of nose, left retroauricular area, posterior neck Lower part of right cheek
Present patient 1
Male
Since birth
3 mos
Present patient 2
Male
Childhood
8 yrs
Patient
Right side of trunk, shoulder, arm, forearm, hand From left preauricular region to oral commissure
Associated diseases
Reference
Congenital dorsal scoliosis, basal cell carcinoma –
8
Congenital dorsal scoliosis Graves’ disease
11
Basal cell carcinoma
17
Flesh-to-yellow plaque composed of multiple coalescent papules Hyperpigmented, hyperkeratotic plaques and nodules Pigmented papules and skin tag –like lesions
Basal cell carcinoma
12
Trichoblastoma
13
–
14
Skin-colored and dark papules Flesh- to dark-colored papules Light-brown colored papules Hypopigmented atrophic patch Firm, hyperpigmented, grouped papules and comedones
– – – – –
14 14 15 6 16
Skin-colored pits and comedones Hypopigmented papules and plaques
–
18
Hypopigmented papules
–
Light brown plaques and papules Hypopigmented macules and plaques
–
10
2
e200 Pediatric Dermatology Vol. 34 No. 4 July/August 2017
to new growths or changes in the lesions of BFH to detect possible BCCs arising on BFHs. We also suggest that BFH should be included in the differential diagnosis of skin conditions following Blaschko’s lines. REFERENCES 1. Brown AC, Crounse RG, Winkelmann RK. Generalized hair-follicle hamartoma. Associated with alopecia, aminoaciduria, and myasthenia gravis. Arch Dermatol 1969;99:478–493. 2. Mehregan AH, Baker S. Basaloid follicular hamartoma: three cases with localized and systematized unilateral lesions. J Cutan Pathol 1985;12:55–65. 3. Morohashi M, Sakamoto F, Takenouchi T et al. A case of localized follicular hamartoma: an ultrastructural and immunohistochemical study. J Cutan Pathol 2000;27:191–198. 4. Grachtchouk V, Grachtchouk M, Lowe L et al. The magnitude of hedgehog signaling activity defines skin tumor phenotype. EMBO J 2003;22:2741–2751. 5. Jih DM, Shapiro M, James WD et al. Familial basaloid follicular hamartoma: lesional characterization and review of the literature. Am J Dermatopathol 2003;25:130–137. 6. Brownstein MH. Basaloid follicular hamartoma: solitary and multiple types. J Am Acad Dermatol 1992;27:237–240. 7. Huang SH, Hsiao TF, Lee CC. Basaloid follicular hamartoma: a case report and review of the literature. Kaohsiung J Med Sci 2012;28:57–60. 8. Lee MW, Choi JH, Moon KC et al. Linear basaloid follicular hamartoma on the Blaschko’s line of the face. Clin Exp Dermatol 2005;30:30–34. 9. Carney RG. Linear unilateral basal cell nevus with comedones. Arch Dermatol 1952;100:187–190.
10. Anderson TE, Best PV. Linear basal-cell naevus. Br J Dermatol 1962;74:20–23. 11. Bleiberg J, Brodkin RH. Linear unilateral basal cell nevus with comedones. Arch Dermatol 1969;100:187– 190. 12. Nelson BR, Johnson TM, Waldinger T et al. Basaloid follicular hamartoma: a histologic diagnosis with diverse clinical presentation. Arch Dermatol 1993;129: 915–917. 13. Kaiser A, Spence RJ, Parwani A et al. Basaloid follicular hamartoma with trichoblastomatous proliferations. J Cutan Med Surg 2003;7:395–398. 14. El-Darouti MA, Marzouk SA, Abdel-Halim MR et al. Basaloid follicular hamartoma. Int J Dermatol 2005;44:361–365. 15. Harman M, Inal€ oz HS, Akdeniz S et al. Congenital non-familial unilateral basaloid follicular hamartoma. J Eur Acad Dermatol Venereol 1999;13:210–213. 16. Kim TH, Oh SJ, Kim YC et al. Segmentally arranged hyperpigmented basaloid follicular hamartoma. Ann Dermatol 2015;27:218–220. 17. Jimenez-Acosta FJ, Redondo E, Baez O et al. Linear unilateral basaloid follicular hamartoma. J Am Acad Dermatol 1992;27:316–319. 18. ElBehairy S, Elbendary A, Moussa Z. Image gallery: linear unilateral basaloid follicular hamartoma: a unique presentation. Br J Dermatol 2016;174:e11. 19. Happle R, Tinschert S. Segmentally arranged basaloid follicular hamartomas with osseous, dental and cerebral anomalies: a distinct syndrome. Acta Derm Venereol 2008;88:382–387. 20. Gumaste P, Ortiz AE, Patel A et al. Generalized basaloid follicular hamartoma syndrome: a case report and review of the literature. Am J Dermatopathol 2015;37:e37–e40.
