In vivo reflectance confocal microscopic findings in a case of trichofolliculoma.

Trichofolliculoma is a rare follicular hamartoma whose dermoscopic features have been scarcely reported. On the other hand, reflectance confocal microscopy features have not been described yet. In the present study, the authors report reflectance confocal microscopy features in a case of trichofolliculoma as squamous hyperplasia forming irregular finger-like protrusions around the hair follicle and papillomatous hyperplasia of the hair follicle epithelium, which correlated with histopathology. This case suggests that reflectance confocal microscopy may help incorrect in vivo diagnosis of trichofolliculoma in cases difficult to diagnose by morphology and dermoscopy.

Management of 3 Proliferating Pilar Tumors: Definition, Differential Diagnosis, and Treatment Options. / Experiencia en el manejo de 3 tumores pilares proliferantes: definición, diagnósticos diferenciales y alternativas terapéuticas.

A proliferating pilar tumor is a rare skin neoplasm that arises from the outer root sheath of a hair follicle. Presentation varies widely, as the tumor can be benign or malignant and has a high probability of recurring after excision. We report our experience managing 3 proliferating pilar tumors with different clinical presentations and pathology findings at Hospital de San José, Bogota, Colombia.

High CD90 (THY-1) expression positively correlates with cell transformation and worse prognosis in basal-like breast cancer tumors.

Breast cancer is the most prevalent cancer among women, with the basal-like triple negative (TNBC) being the most agressive one, displaying the poorest prognosis within the ductal carcinoma subtype. Due to the lack of adequate molecular targets, the diagnosis and treatment of patients with the TNBC phenotype has been a great challenge. In a previous work, we identified CD90/Thy-1 as being highly expressed in the aggressive high malignancy grade Hs578T basal-like breast tumor cell line, pointing to this molecule as a promising breast tumor marker, which should be further investigated. Here, CD90 expression was analyzed in human breast cancer samples and its functional role was investigated to better assess the oncogenic nature of CD90 in mammary cells. Quantification of CD90 expression in human breast cancer samples, by tissue microarray, showed that high CD90 positivity correlates with metastasis and poor patient survival in the basal-like subtype. The functional genetic approach, by overexpression in the CD90 cDNA in a basal-like normal mammary cell line (MCF10A) and knockdown in a highly malignant cell line (Hs578T), allowed us to demonstrate that CD90 is involved with several cellular processes that lead to malignant transformation, such as: morphological change, increased cell proliferation, invasiveness, metastasis and activation of the EGFR pathway. Therefore, our results reveal that CD90 is involved with malignant transformation in breast cancer cell lines and is correlated with metastasis and poor patient survival in the basal-like subtype, being considered as a promising new breast cancer target.

Benign follicular tumors

Abstract: Benign follicular tumors comprise a large and heterogeneous group of neoplasms that share a common histogenesis and display morphological features resembling one or several portions of the normal hair follicle, or recapitulate part of its embryological development. Most cases present it as clinically nondescript single lesions and essentially of dermatological relevance. Occasionally, however, these lesions be multiple and represent a cutaneous marker of complex syndromes associated with an increased risk of visceral neoplasms. In this article, the authors present the microscopic structure of the normal hair follicle as a basis to understand the type and level of differentiation of the various follicular tumors. The main clinicopathological features and differential diagnosis of benign follicular tumors are then discussed, including dilated pore of Winer, pilar sheath acanthoma, trichoadenoma, trichilemmoma, infundibuloma, proliferating trichilemmal cyst/tumor, trichoblastoma and its variants, pilomatricoma, trichodiscoma/fibrofolliculoma, neurofollicular hamartoma and trichofolliculoma. In addition, the main syndromes presenting with multiple follicular tumors are also discussed, namely Cowden, Birt-Hogg-Dubé, Rombo and Bazex-Dupré-Christol syndromes, as well as multiple tumors of follicular infundibulum (infundibulomatosis) and multiple trichoepitheliomas. Although the diagnosis of follicular tumors relies on histological examination, we highlight the importance of their knowledge for the clinician, especially when in presence of patients with multiple lesions that may be the cutaneous marker of a cancer-prone syndrome. The dermatologist is therefore in a privileged position to recognize these lesions, which is extremely important to provide further propedeutic, appropriate referral and genetic counseling for these patients.

Three different clinical faces of the same histopathological entity: hair follicle nevus, trichofolliculoma and accessory tragus.

BACKGROUND: Hair follicle nevus is a rare, congenital hamartoma with follicular differentiation characterized histologically by numerous, tiny, mature hair follicles. Trichofolliculoma, the histopathological features of which are quite similar to those of hair follicle nevus, is also a hamartoma that differs from hair follicle. Accessory tragus is a relatively common, benign congenital abnormality of the external ear with an incidence rate of 1 to 10 per 1,000 live births. OBJECTIVE: This study seeks to assess the discriminatory value of currently available, histological criteria in the differential diagnosis of hair follicle nevus, accessory tragi and trichofolliculoma. METHODS: Twenty-one patients comprising 9 cases of hair follicle nevus, 8 accessory tragi patients and 4 trichofolliculoma cases, were recruited to perform the study. RESULTS: There were 10 males and 11 females in the study group. No significant difference was observed between the three study groups in terms of age, gender or histopathological parameters such as density of hair follicles, subcutaneous fat score and presence of connective tissue framework. Cartilaginous component was seen in 8 cases that were diagnosed as accessory tragi, while central cyst and radiating hair follicles were seen in 4 cases which were diagnosed as trichofolliculoma. CONCLUSION: The results of our study showed that diagnostic discrimination of these diseases could be made only with the clinicopathologic correlation because of their clinical and histopathological similarities.

Three different clinical faces of the same histopathological entity: hair follicle nevus, trichofolliculoma and accessory tragus

AbstractBACKGROUND:Hair follicle nevus is a rare, congenital hamartoma with follicular differentiation characterized histologically by numerous, tiny, mature hair follicles. Trichofolliculoma, the histopathological features of which are quite similar to those of hair follicle nevus, is also a hamartoma that differs from hair follicle. Accessory tragus is a relatively common, benign congenital abnormality of the external ear with an incidence rate of 1 to 10 per 1,000 live births.OBJECTIVE:This study seeks to assess the discriminatory value of currently available, histological criteria in the differential diagnosis of hair follicle nevus, accessory tragi and trichofolliculoma.METHODS:Twenty-one patients comprising 9 cases of hair follicle nevus, 8 accessory tragi patients and 4 trichofolliculoma cases, were recruited to perform the study.RESULTS:There were 10 males and 11 females in the study group. No significant difference was observed between the three study groups in terms of age, gender or histopathological parameters such as density of hair follicles, subcutaneous fat score and presence of connective tissue framework. Cartilaginous component was seen in 8 cases that were diagnosed as accessory tragi, while central cyst and radiating hair follicles were seen in 4 cases which were diagnosed as trichofolliculoma.CONCLUSION:The results of our study showed that diagnostic discrimination of these diseases could be made only with the clinicopathologic correlation because of their clinical and histopathological similarities.

Benign follicular tumors.

Benign follicular tumors comprise a large and heterogeneous group of neoplasms that share a common histogenesis and display morphological features resembling one or several portions of the normal hair follicle, or recapitulate part of its embryological development. Most cases present it as clinically nondescript single lesions and essentially of dermatological relevance. Occasionally, however, these lesions be multiple and represent a cutaneous marker of complex syndromes associated with an increased risk of visceral neoplasms. In this article, the authors present the microscopic structure of the normal hair follicle as a basis to understand the type and level of differentiation of the various follicular tumors. The main clinicopathological features and differential diagnosis of benign follicular tumors are then discussed, including dilated pore of Winer, pilar sheath acanthoma, trichoadenoma, trichilemmoma, infundibuloma, proliferating trichilemmal cyst/tumor, trichoblastoma and its variants, pilomatricoma, trichodiscoma/fibrofolliculoma, neurofollicular hamartoma and trichofolliculoma. In addition, the main syndromes presenting with multiple follicular tumors are also discussed, namely Cowden, Birt-Hogg-Dubé, Rombo and Bazex-Dupré-Christol syndromes, as well as multiple tumors of follicular infundibulum (infundibulomatosis) and multiple trichoepitheliomas. Although the diagnosis of follicular tumors relies on histological examination, we highlight the importance of their knowledge for the clinician, especially when in presence of patients with multiple lesions that may be the cutaneous marker of a cancer-prone syndrome. The dermatologist is therefore in a privileged position to recognize these lesions, which is extremely important to provide further propedeutic, appropriate referral and genetic counseling for these patients.

Carcinoma de la mama triple negativo aspectos morfológicos y expresión de CK 5/6 / Triple negative breast cancer morphological aspects and CK 5/6 expression

El carcinoma mamario es una enfermedad heterogénea, parámetros de clasificación, factores pronósticos, no siempre predicen su curso clínico. La genética molecular, los ha estratificado en grupos diferentes a la clasificación morfológica. Trabajos respaldan que un grupo específico: carcinoma de “tipo basal” tiene peor pronóstico, es frecuentemente triple negativo, es decir: RE(-), RP(-), C-erbB-2(-) expresa citoqueratinas de epitelios basales, como la citoqueratina 5/6 (CK5/6, planteamos determinar los aspectos morfológicos de estos carcinomas, identificar la frecuencia en la que expresan CK5/6 por inmunohistoquímica, relacionarlos con parámetros clínicos disponibles. Se seleccionaron 91 carcinomas entre 2003-2008 se les realizó CK5/6. 34 (37,4 por ciento) fueron TN-CK5/6(+) y 57 (62,6 por ciento) fueron TN-CK5/6(-). Las características morfológicas descritas se observaron en ambos grupos, más frecuentemente en los carcinomas TN-CK5/6(+). La detección de estos tumores por inmunohistoquímica es una forma práctica, rentable de identificar a este grupo de peor pronóstico en la práctica diaria.

Breast cancer is heterogeneous disease classification parameters prognostic factors are not always predictors its clinical course. Molecular genetics are categorizing in different ways, as the well-known morphologic classification. Studies endorse specific group within this classifying system: Basal-like carcinomas, has worst prognosis; tends to be triple-negative: ER(-), RP(-), Erb-B2(-); expresses basal cytokeratins, such as cytokeratin 5/6 (CK5/6). Considered determining morphological aspects, frequency in which they express CK5/6 through immunohistochemistry, and contrasting them to existing clinical parameters. 91 carcinomas were selected between the years 2003-2008 and checked for CK5/6. Or the aforementioned cases, 34 (37.4 percent) resulted TN-CK5/6(+) and 57(62.6 percent) resulted TN-CK5/6(-). Morphological aspects described for and carcinomas were observed in both groups, though they were more frequent in breast carcinomas TN-CK5/6(+). For this reason, detecting these tumors using immunohistochemistry is a practical, worthwhile, and convenient way to identify this group with the worst prognosis on our daily routines.

[Eyelid trichoepithelioma--report of 2 cases]. / Tricoepitelioma palpebral--relato de 2 casos.

Trichoepithelioma is a benign skin tumor and is most commonly found on the face, however, there are few reports about its occurrence on the eyelids. It is not usually recognized because of its rarity, origin, biological potential, and controversial classification. The purpose of this paper is to report two cases of solitary trichoepithelioma on the eyelid, their histopathology and treatment. This lesion should be considered when a single solid nodule on the face appears, and can be differentiated from basal-cell carcinoma. Histopathologic confirmation is essential.

Trichoepitheliomatous infiltration of the skin simulating leprosy.

A 13-year-old girl had a six-year history of infiltrated erythematous plaques on the face, alopecia of the eyebrows, diffuse alopecia of the scalp, and absence of body hair. Histologically, the lesions on the face and body corresponded to trichoepitheliomas. The lesions on the face clinically simulated lepromatous leprosy. This case probably represents an entity not previously described.