Lymphomas of the female genital tract - A study of 186 cases and review of the literature

Malignant lymphomas in the female genital tract are rare, and those arising from this tissue system are extremely uncommon. Most pertinent reports lack clear references to the accepted classifications or failed to apply immunomarkers and molecular techniques for a reliable diagnosis. We analyzed a large group of patients with primary and secondary lymphomas of the female genital tract classified on the basis of the recent WHO consensus. A total of 186 patients with malignant lymphoma detected in the female genital tract were selected from the files of the Kiel Lymphoma Registry covering the period of 1974 to 2004. Stringent criteria were applied to separate systemic versus secondary lymphomas. All cases were reviewed on the basis of conventionally stained sections, relevant immunohistochemistry using the alkaline phosphatase/anti-alkaline phosphatase technique, and clinical information, as far as available. When required, gene rearrangement analysis was performed, including TCR-gamma chain gene and the three FR fragments of the IgG heavy chain gene. In addition, typical chromosomal translocations were detected by means of the FISH technique to verify the diagnosis, where needed. Thirty-seven percent of the cases were systemic lymphomas and 63% were mostly extranodal lymphomas primary to the female genital tract. The adnexa were involved in 87 cases, followed by uterine corpus in 23 cases, uterine cervix in 17 cases, portio in 9 cases, vagina in 11 cases, and vulva including clitoris in 8 cases. In 31 cases, two or more adjacent sites were involved. In both (primary and secondary) groups, the adnexa were the prevailing site of involvement. As expected, the overwhelming majority of cases were of B phenotype. The most frequent type of lymphoma proved to be diffuse large B-cell lymphoma, closely followed by follicular lymphoma, including all 3 grades of malignancy. Burkitt lymphoma showed a rather similar frequency. Marginal zone lymphoma occurred exclusively as primary lesions in the uterine mucosa. Lymphoplasmacytic lymphoma was restricted to the vulvo-vaginal area and occurred in women over 60 years of age. In conclusion, our study provides a thorough overview of various types of lymphoma affecting the female genital tract primarily or secondarily, which were classified on the basis of a widely accepted WHO classification. Although quite rare, our report should remind the pathologist of considering malignant lymphomas while reading biopsies taken from female genital organ.