Immunohistochemical evaluation of vitiliginous hair follicle melanocyte reservoir: is it retained?

BACKGROUND: Vitiligo is an acquired depigmentaion of skin and hair. The presence of white hair within vitiligo lesions is considered a bad prognostic sign since these lesions are difficult to repigment. Melanocyte reservoir was not extensively studied in vitiliginous white hair. OBJECTIVE: To evaluate pigment cell reservoir in vitiliginous black and white hair. METHOD: Using immunohistochemical technique, skin biopsies from 30 vitiligo patients (including either black or white hair) and 10 age- and gender-matched healthy subjects were examined. Human Melanoma Black-45 (HMB-45) was used for detecting active melanocytes and Tyrosinase Related Protein 2 (TRP2) for detecting the whole melanocyte lineage including melanocyte stem cells (MelSC). RESULTS: About 61.1% of black hair was positive for HMB-45 and 83.3% was positive for TRP2. About 25% of white hair was positive for HMB-45 and 75% retained TRP2 positivity. Follicular HMB-45 expression and TRP2 expression percentage were significantly lower in white than black hair (P = 0.05, 0.04 respectively). Epidermal HMB-45 and TRP2 expression percentages were significantly higher in lesions containing black rather than white hair (P < 0.001, P = 0.05 respectively). Black hair was significantly associated with histologically pigmented hair follicles (P = 0.049), and with residual interfollicular melanin pigment (P = 0.007). CONCLUSION: Melanocytes, either active (melanotic) or inactive (amelanotic which may include MelSC), are not totally absent from vitiliginous white hair. However, intact melanocyte reservoir was observed more in black than white hair. This may add avenues for future research about the possibility of white vitiliginous hair to repigment.

Immunohistochemical expression of cyclin A in testicular biopsies of fertile and infertile men: correlation with the morphometry of seminiferous tubules.

Cyclin A is a member of the cyclin family of proteins, which are required for both the mitotic and meiotic divisions that characterise spermatogenesis in human and other mammalian species. The data on cyclin A expression in various human spermatogenic disorders and its relationship to the morphology of seminiferous tubules are not well clarified. This study aimed to evaluate the immunohistochemical expression of cyclin A in testicular biopsies of different spermatogenic disorders correlating with the morphology of seminiferous tubules using morphometry tools. Immunohistochemical evaluation of cyclin A was carried out on testicular biopsies obtained from 48 infertile males (nonobstructive azoospermia) and 15 normal subjects together with using semiautomatic morphometric analysis for evaluation of seminiferous tubules. Cyclin A is expressed in 100% of normal and hypospermatogenesis groups and in 80% of maturation arrest group, with complete absence in Sertoli cell only group. In positive cases, cyclin A stained the nuclei of spermatogonia and primary spermatocytes with a higher intensity of expression in normal cases compared with infertile group. Cyclin A expression was significantly associated with the different examined morphometric parameters. Cyclin A is involved in both mitosis and meiosis of human spermatogenesis as it is expressed in spermatogonia and primary spermatocytes. Morphometry of human testis is intimately correlated with the testicular histopathology.

Splenic histiocyte-rich pseudotumor following chemotherapy for non Hodgkin diffuse large B cell lymphoma.

Chemotherapy may induce mass lesion in rare conditions, which can be easily mistaken as a residual tumor mass. In this report, we describe a mass affecting spleen in a patient received chemotherapy for non Hodgkin diffuse large B cell lymphoma. This mass proved histologically to be non neoplastic formed of sheets of histiocytes and xanthoma cells, which is called histiocyte-rich pseudotumor. This report describes this rare lesion and the possible differential diagnosis.

Ephrin A4 expression in osteosarcoma, impact on prognosis, and patient outcome.

BACKGROUND: Ephrin A4 is one of the ephrin ligand molecules belonging to the tyrosine kinases receptor family. It was originally identified in a T-lymphoma cell line and seen to be expressed in human adult tissue as well as several tumor types. In our previous study, we showed the unique pattern of ephrin A4 immunohistochemical staining, which differed according to the type of examined bone specimens (normal bone, primary, and metastatic osteosarcoma lesions). The aim of the present study is to evaluate the prognostic impact of ephrin A4 expression in a group of primary osteosarcoma patients. MATERIALS AND METHODS: Ephrin A4 immunohistochemical expression was carried out on 47 primary osteosarcoma cases. RESULTS: Ephrin A4 was expressed in 82.9% of osteosarcoma cases with cytoplasmic localization in 58.9% of positive cases. The cytoplasmic pattern was significantly associated with aggressive histopathological types of osteosarcoma (P = 0.02), advanced stage (P = 0.04), the presence of metastasis (P = 0.03), inferior response to neoadjuvent chemotherapy (P = 0.04), and tended to be associated with a shorter event-free survival (P = 0.09). CONCLUSIONS: The cytoplasmic pattern of ephrin A4 could identify a subgroup of primary osteosarcoma patients with a high liability for progression, poor prognosis, and inferior response to chemotherapy.