Dermoscopic characteistics of trichoblastoma: a preliminary investigation / 中华皮肤科杂志

Objective:To preliminarily investigate dermoscopic characteristics of trichoblastoma, and to provide ideas for clinical diagnosis of trichoblastoma.Methods:Clinical data were collected from 5 patients with trichoblastoma who underwent both dermoscopic and histopathological examinations in Wuhan No.1 Hospital from November 2018 to July 2021, and dermoscopic features were analyzed retrospectively.Results:According to the presence or absence of pigments, trichoblastoma was divided into 2 subtypes: pigmented trichoblastoma (3 cases) and non-pigmented trichoblastoma (2 cases) . Dermoscopic examination of the 3 cases of pigmented trichoblastoma showed blue-gray ovoid nests (3 cases) , arborizing vessels (2 cases) , blue-gray globules (2 cases) , bright white structureless areas (2 cases) , concentric structures (1 case) and ulcers (1 case) ; no yellow-whitish homogenous structure was found. As for non-pigmented trichoblastoma, dermoscopic features included arborizing vessels (2 cases) , yellow-whitish homogenous structures (2 cases) , bright white structureless areas (2 cases) and blue-gray globules (1 case) ; no ulcers or blue-gray ovoid nests were observed in either case.Conclusion:Dermoscopic patterns differ between pigmented and non-pigmented trichoblastoma, so dermoscopy can provide preliminary diagnostic clues for trichoblastoma.

Masquerades less known: Case report of benign hair follicle tumors

Benign eyelid tumors derived from hair follicles are rare and frequently misdiagnosed as basal-cell carcinoma when evaluation is based on clinical evidence alone. The discrepancy between the clinical aspect and the histological diagnosis can be as high as 30–40%, even for experienced clinicians. Unfortunately, this masquerade is not only clinical but also histological. Patients may be subjected to unnecessarily extensive surgery. We present a case report of three patients clinically diagnosed as malignancy but histopathologically proven as benign hair follicle tumors.

Syringocystadenoma papilliferum and trichoblastoma arising in the nevus sebaceous

Nevus sebaceous (NS) is a clinically common benign tumor and has a high potential to develop into a great diversity of neoplasms of epidermal and adnexal origins. However, it is a rare phenomenon of the coexistence in a single NS with two or more skin tumors. We report a case of a 58-year-old woman with two kinds of neoplastic proliferation including syringocystadenoma papilliferum and trichoblastoma arising in NS on the scalp.

Trichoblastoma and Compound Nevus Arising from Nevus Sebaceus / 대한피부과학회지

Nevus sebaceous is a common congenital cutaneous hamartoma occurring mainly on the face and scalp. It is well known that secondary neoplasms can be easily observed in the primary lesion. However, a case of trichoblastoma and compound nevus concurrently arising from nevus sebaceous has not been previously reported. A 26-year-old woman presented with a well-demarcated atrophic skin-colored plaque on her scalp from birth. On the plaque, a black dome-shaped round nodule and a brownish nodule with irregular margins were found one week previously without subjective symptoms. Histopathological examination of the central plaque lesion revealed epidermal hyperplasia and hyperplasia of the sebaceous glands and eccrine glands. In addition, ectopic, dilated apocrine glands were revealed in the lower dermis, and the hair follicles remained small and primordial, consistent with nevus sebaceous. A section of the black nodule showed palisading basaloid cells surrounded by abundant fibrous stroma. Nests of nevus cells were found at the dermo-epidermal junction and dermis in the brownish nodule. Based on these findings, the black nodule and brownish nodule were diagnosed as trichoblastoma and compound nevus, respectively. Herein, we report an interesting case of trichoblastoma and compound nevus concurrently arising from nevus sebaceous, which is, to our knowledge, the first such report in the dermatologic literature.

A Case of Trichoblastoma, Tumor of the Follicular Infundibulum, Sebaceoma, and Sebaceous Hyperplasia Arising from Nevus Sebaceus / 대한피부과학회지

Nevus sebaceus is a congenital hamartoma with epidermal, follicular, and apocrine elements. Several skin appendage tumors can evolve secondarily from nevus sebaceus. Two different tumors often develop simultaneously on a nevus sebaceus lesion, but the growth of more than two tumors is rare. Herein, we report a case of four appendage tumors including trichoblastoma, tumor of the follicular infundibulum, sebaceoma, and sebaceous hyperplasia within a single nevus sebaceus lesion on the face of a 76-year-old female.

Clinicopathological analysis of 3 cases of trichoblastoma / 重庆医学

Objective To summarize and study the clinicopathologic features,diagnosis and differential diagnosis of tricho-blastoma (TB).Methods The clinicopathological characteristics,histomorphology features and immunophenotype features of TB and differential diagnosis with multiple diseases in 3 cases of TB were retrospectively analyzed;moreover,5 cases of basal cell carci-noma were selected and performed the immunophenotype detection,which focused on the differential diagnosis with TB.Results The masses in 3 cases were located under the skin without connecting with the epidermis and were composed of basal-like cells with palisade arrangement of peripheral cells.The case 1 showed unequal-sized multiple cyst cavities and pigment deposition and was di-agnosed as pigmented TB.The papillary mesenchymal bodies were found in case 2,which was diagnosed as TB.The basal cells of tumor in case 3 distributed as palisade arrangement and formed the wave structure,which was diagnosed as rippled-pattern TB.AR in 3 cases and Bcl-2 in 2 cases were negative expression,CK20 in 1 case was sporadically positive,CD10 stroma and papillary struc-ture in 3 cases were positive,paliform-like arrange tumor cells CD10 around basal cell carcinomas in 5 cases were positive,AR in 4 cases was positive,Bcl-2 in 3 cases was positive and CK20 in 5 cases was negative.Conclusion TB is a benign tumor derived from the hair follicle germinal epithelium with a good prognosis after complete resection and the differential diagnosis focuses on basal cell carcinomas.

Tricoblastoma de localización acral, una ubicación infrecuente: reporte de un caso / Acral location trichoblastoma, a location infrequent: report of a case

Tricoblastoma es una neoplasia anexial benigna de la piel, de difícil diagnóstico clínico, por su baja prevalencia y por la ausencia de características clínicas patognomónicas. Por esta razón, es la biopsia la que hace el diagnóstico definitivo, ya que se suele confundir con otras neoplasias anexiales. Se presenta caso clínico de una mujer de 87 años con historia de cinco años de evolución de lesión nodular, sésil y simétrica ubicada en la falange proximal del primer ortejo del pie izquierdo, la cual había presentado un crecimiento progresivo en los últimos seis meses, refiriendo molestias leves con el calzado, sin mayores complicaciones. La biopsia excisional de la lesión, es informada como tricoblastoma. El escaso conocimiento del tricoblastoma lleva a la incorrecta interpretación de su forma clínica, lo que resulta relevante, pues su principal diagnóstico diferencial corresponde al carcinoma basocelular (CBC). Se presenta el caso clínico por lo infrecuente de su localización, lo que indujo a confusión del diagnóstico. No se debe olvidar que el tricoblastoma es una neoplasia anexial benigna, que puede presentarse en cualquier sitio en el que existan folículos pilosebáceos, por lo que hay que considerarlo dentro de los diagnósticos diferenciales de cualquier neoplasia anexial.

Trichoblastoma is a skin benign adnexal neoplasm, clinical diagnosis is difficult because presents a low prevalence, it has not any pathognomonic clinical characteristics and it's often mistaken with other adnexal tumors; so the biopsy makes the definitive diagnosis. We report the case of a woman of 87 years with a history of 5 years of evolution of a nodular, sessile and symmetrical lesion located in the proximal phalanx of the first left toe, which had presented a progressive growth in the last 6 months, she presented mild discomfort with footwear, without major complications. The excisional biopsy of the lesion, was reported as a trichoblastoma. Poor knowledge of trichoblastoma leads to a clinical misinterpretation, which is relevant, because its main differential diagnosis corresponds to basal cell carcinoma (BCC). A case located on an extremely rare location is presented, which led to confusion in clinical diagnosis. You must not forget that trichoblastoma is an adnexal benign tumor, which can occur at any site with pilosebaceous follicles, so we should consider in the differential diagnoses of any skin adnexal neoplasms.

Nevus sebaceus with basal cell carcinoma, poroma, and verruca vulgaris.

Nevus sebaceus (NS) is a congenital, benign, hamartomatous lesion and it is possible to see several benign or malignant tumors accompanying it. One of these is the poroma, which is very rare, and has only been reported twice before, in the English literature. In this paper, we presented two new cases of NS. One of them was a 40‑year‑old male who presented with a congenital skin lesion on his temporoparietal region. This lesion was composed of four different lesions, including NS, poroma, basal cell carcinoma (BCC), and verruca vulgaris. The second patient was a 41‑year‑old male presenting with a yellow‑brown patch on the scalp. This lesion was comprised of NS and BCC. In addition to these presentations, we discussed the differential diagnosis between BCC and trichoblastoma, both of which are likely to be seen with NS. For this purpose, we recommended an immunohistological panel, which may be useful for differentiating these two morphologically similar lesions.

Composite Tumor Associating Trichoblastoma and Seborrheic Keratosis

Seborrheic keratosis is a common benign epidermal tumor histologically composed of basaloid and squamous cells. It mainly occurs on the face, scalp, and trunk, and presents clinically as a well-circumscribed, brownish to black papule, nodule, or plaque. Trichoblastoma is a relatively rare benign, slow-growing tumor showing differentiation toward the primitive hair follicle. It clinically manifests as a solitary, skin to erythematous colored, well-circumscribed dermal nodule located predominantly on the head and neck with a predilection for the scalp. Histologically, a well-demarcated mass of follicular germinative cells that show various degrees of differentiation, arranged in lobules, sheets, and nests, is located in the dermis or subcutaneous fat layer. We report the case of a 28-year-old female patient with a solitary, 2.0x4.0-cm black plaque with a 0.7-cm skin-colored nodule on the scalp. Histologically, the entire black plaque had prominent hyperkeratosis, acanthosis, and papillomatosis with horn cysts. The central nodule showed well-circumscribed, various-sized dermal tumor lobules without a connection to the overlying epidermis. The lobular aggregation was composed of numerous basaloid epithelial nests and multiple primitive papillary structures with distinct peripheral palisading of nuclei. According to these findings, the scalp lesion was diagnosed as a composite tumor associating trichoblastoma and seborrheic keratosis.

Composite Tumor Associating Trichoblastoma and Seborrheic Keratosis

Seborrheic keratosis is a common benign epidermal tumor histologically composed of basaloid and squamous cells. It mainly occurs on the face, scalp, and trunk, and presents clinically as a well-circumscribed, brownish to black papule, nodule, or plaque. Trichoblastoma is a relatively rare benign, slow-growing tumor showing differentiation toward the primitive hair follicle. It clinically manifests as a solitary, skin to erythematous colored, well-circumscribed dermal nodule located predominantly on the head and neck with a predilection for the scalp. Histologically, a well-demarcated mass of follicular germinative cells that show various degrees of differentiation, arranged in lobules, sheets, and nests, is located in the dermis or subcutaneous fat layer. We report the case of a 28-year-old female patient with a solitary, 2.0x4.0-cm black plaque with a 0.7-cm skin-colored nodule on the scalp. Histologically, the entire black plaque had prominent hyperkeratosis, acanthosis, and papillomatosis with horn cysts. The central nodule showed well-circumscribed, various-sized dermal tumor lobules without a connection to the overlying epidermis. The lobular aggregation was composed of numerous basaloid epithelial nests and multiple primitive papillary structures with distinct peripheral palisading of nuclei. According to these findings, the scalp lesion was diagnosed as a composite tumor associating trichoblastoma and seborrheic keratosis.

Trichoepithelioma Multiplex: A Study of the Relationship between the Anatomical Location and the Histopathological Features.

Trichoepithelioma multiplex is a rare, benign cutaneous genodermatosis of disputed histogenesis, consisting of tumors of trichogenic origin. Aim: To explore the relationship between the anatomical location and the histopathological features of the trichoepitheliomas in a patient cohort with Trichoepitheliomamultiplex. Methods: The study was conducted over the period 1995-2008 at the tertiary Dermatology and Anatomical Pathology referral centers of the University of Pretoria. The clinical and pathological features of confirmed cases were assessed. Sixty four H&E stained sections from skin lesions distributed over different body areas were examined with regard to 16 histopathological parameters for the evidence of follicular differentiation and features useful in distinguishing trichoepithelioma from basal cell carcinoma. Special stains were employed for the demonstration of mucin (PAS, Alcian blue) amyloid (Congo red) calcium (Von Kossa) and epithelial structures (AE1/AE3-CK antibodies). Results:Trichoepithelioma multiplex was an uncommon diagnosis (20 patients). African patients were preponderant (16 vs.4 Caucasians) with slight male predominance (11 vs. 9 females). Sporadic cases prevailed (15 vs. 5 familial cases).A wide variation in the severity of the clinical presentation was observed, young black males and familial cases being more severely affected. The face was involved in all cases (30 biopsies), followed by the scalp and back (13 biopsies each) and the neck (8 biopsies). There were variations in histopathological patterns with considerable overlap between them. Special stains differentiated between the tumours from different body areas with the exception of AE1/AE3-CK antibodies. Foreign body reactions were common in lesions showing many keratinous cysts and follicular damage. Trichoepithelioma was seen in relation to a benign pigmented intradermal nevus in one biopsy and adjacent to a basal cell carcinoma in two cases Conclusion: A positive correlation could be established between the histopathological pattern of trichoepitheliomas and the body area from which the lesions were removed.

Development of Six Tumors in a Sebaceus Nevus of Jadassohn: Report of a Case

Nevus sebaceus of Jadassohn is a congenital cutaneous hamartoma comprised of multiple skin structures. It has the potential to develop into variety of neoplasms of various epidermal adnexal origins. While multiple tumors may occasionally arise, it is unusual for more than four tumors to arise simultaneously within a single sebaceus nevus. Here in, we report a case of a 70-year-old woman with six neoplastic proliferations including a syringocystadenoma papilliferum, pigmented trichoblastoma, tubular apocrine adenoma, sebaceoma, tumors of follicular infundibulum and superficial epithelioma with sebaceus differentiation arising in a long standing nevus sebaceus on the scalp. Our case is extraordinary because a single nevus sebaceus contained six neoplastic proliferations with differentiation toward the folliculosebaceous-apocrine unit.

Trichoblastoma Mimicking Epidermal Cyst on the Trunk / 대한피부과학회지

Trichoblastoma is a rare, benign skin tumor of adnexal origin that differentiates toward the hair germ, the embryonic precursor of a hair follicle. Clinically, it presents as a slow growing, solitary, well-circumscribed nodule located predominantly in the head and neck area, with a predilection for the scalp. The trunk, proximal extremities and perianal and genital regions may also be affected. We herein present a case of trichoblastoma which occurred on the trunk as a solitary subcutaneous mass with a central tiny pore in 53-year-old man.

A Case of Trichogerminoma

Trichogerminoma is a rare neoplasm which was first described in 1992 and there is still controversy over its inclusion into the spectrum of trichoblastoma. A 79-year-old woman presented with a 5-year history of an asymptomatic nodule on the left posterior neck. Histologically, the lesion revealed a well-demarcated deep dermal nodule surrounded by a pseudocapsule. The tumor was composed of lobules with basophilic cells and some of the lobules displayed a distinctive pattern of densely packed 'cell balls' with peripheral condensation. Immunohistochemically, the tumor cells showed zonal CK5/6 immunoactivity in contrast with the negatively stained 'cell balls'. These characteristics were compatible with the diagnosis of trichogerminoma. We report here on a rare case of a hair germ tumor called trichogerminoma.

Pigmented trichoblastoma with sebaceous hyperplasia.

Trichoblastoma is a rare benign trichogenic tumour with epithelial and mesenchymal components recapitulating the germinal hair bulb and associated mesenchyme. A 50- year- old male patient presented with slowly enlarging circumscribed solid nodule measuring 4x3x4.5 cm over the tip of the nose. Microscopy of tumour revealed nodular tumour spanning the entire dermis with collection of mesenchymal cells resembling follicular papilla. Areas of pigmentation and sebaceous hyperplasia were noted. There is a need for differentiation of this tumor which is benign, from other pigmented tumors having basaloid arrangement of cells such as basal cell carcinoma.

Pigmented Trichoblastoma Arising from the Nevus Sebaceous: A Rare Case in Korea

Trichoblastoma is occasionally observed in association with a pre-existing nevus sebaceous in the Korean literature. However, there has been no report on the pigmented type. Herein, we report the first Korean case of a pigmented trichoblastoma arising from the nevus sebaceous on the forehead. A 28-year-old male presented with a dark nodular lesion within a yellowish plaque on the forehead. The surrounding yellowish plaque on the forehead had existed since birth. The central, dark-pigmented nodule began to appear three years ago and enlarged gradually. Histopathologic findings of central pigmented lesion showed heavy melanin deposits within and around the tumor nests. Complete excision was made as treatment.

A Case of Melanotrichoblastoma / 대한피부과학회지

Melanotrichoblastoma is a variant of pigmented trichoblastoma that shows highly pigmented epithelial lobules and differentiation toward the hair bulb. Histologically, the tumor presents features of trichoblastoma, and the histological findings are remarkable by virtue of the heavy melanin deposits found within and around the tumor cell nests. For the immunohistochemistry, abundant dendritic melanocytes (with the expressions of S100 protein, tyrosinase and most importantly, gp100/HMB45) are found within the tumor masses. We report here on a rare case of melanotrichoblastoma in a 57 year-old female patient.

A Case of Trichobalstic Carcinoma / 대한피부과학회지

Trichoblastoma is a benign cutaneous neoplasm that consists of follicular germinative cells. There have only been a few case reports describing the malignant counterpart of trichoblastoma. We report trichoblastic neoplasms that show histological features of malignancy. The histological sections revealed locally aggressive neoplasms showing prominent differentiation towards hair germ and follicular sheath with formation of papillary mesenchymal bodies and follicular bulb-like structures. The tumor was widely excised with a clear margin. No sign of recurrence has been noted 1 year later.

Two Cases of Rippled-pattern Trichoblastoma / 대한피부과학회지

In the tumor, several histologic variants have been described including a rippled-pattern variant. The unique finding of rippled-pattern trichoblastoma is a peculiar arrangement of the basaloid cells in linear rows parallel to one another, resembling the palisading of nuclei of Verocay bodies. Only a few case reports of rippled-pattern trichoblastoma have been reported in the English literature, but there has been no report in the Korean literature. Herein we report two cases of rippled-pattern trichoblastoma.

A Case of Cutaneous Lymphadenoma as a Variant of Trichoblastoma / 대한피부과학회지

Cutaneous lymphadenoma is a benign epithelial neoplasm with lymphoepithelial infiltration that is supposed to be from a pilosebaceous origin. We report a 44-year-old man with a nodule on the pre-auricular area showing basaloid proliferation, intraepithelial lymphocytes and immature pilosebaceous structures. The findings of our case make it possible to diagnose a cutaneous lymphadenoma with follicular differentiation and supports this occurs as a variant form of nodular trichoblastoma with adamantinoid features.