Hodgkin's lymphoma. An immunohistochemical profile in northern Iraq

OBJECTIVE: To evaluate the expression of several immunohistochemical markers in Hodgkin's lymphoma (HL), and to determine the relative frequency of HL subtypes. METHODS: From January 2010 through January 2013, 42 HL cases were included in this case series study. Cases were collected from Al-Jumhori Teaching Hospital and private laboratories in Nineveh province, Iraq. The tumors were subtyped according to the World Health Organization classification system. Several markers including CD30, CD15, CD20, CD79a, CD3, and CD43 were evaluated immunohistochemically. RESULTS: The patients' ages ranged from 5-81 years (mean: 32). A bimodal age distribution was discerned, with most cases in the third decade (26.2%). Male to female ratio was 1.6:1. Histopathological subtyping revealed that 33 cases (78.6%) were nodular sclerosis HL, 8 cases (19%) were mixed cellularity HL, and one case (2.4%) was nodular lymphocyte-predominant HL. The CD30 marker was expressed in all classical HL cases (100%); while, CD15 was detected in 51.8% of cases. The nodular lymphocyte-predominant HL was CD30 and CD15 negative, but CD20 and epithelial membrane antigen (EMA) were positive. There was no significant relation between CD15 expression, and both patients' age and HL subtypes. CONCLUSION: The CD30 marker was expressed in 100% of cases of classical HL, while CD15 was positive in 51.8% only. Nodular sclerosis HL was the most common subtype of HL (78.6%), followed by mixed cellularity HL.