Hematologic malignancies with primary retroperitoneal presentation - Clinicopathologic study of 32 cases

Context.-The retroperitoneum is an uncommon location for primary lymphomatous involvement. Initial presentation of disease in this site (primary retroperitoneal lymphoma) is considered to be rare. Because of the uncommon anatomic location, the diagnosis and subsequent management of these patients tend to be difficult for both pathologists and clinicians. Objective.-This report describes our experience during a period of 6 years 4 months with patients with hematologic malignancies primarily presenting in the retroperitoneum. Design.-A retrospective search of our medical records generated 32 patients who presented initially with abdominal pain or discomfort as their predominant symptom and who were found by imaging studies to have retroperitoneal mass or masses. All the histopathology slides were reviewed and classified based on the World Health Organization classification. Results.-There were 13 male and 19 female patients. Tumor types included diffuse large B-cell lymphoma (n = 12); grade 1 follicular lymphoma (n = 4); grade 3 follicular lymphoma (n = 1); B chronic lymphocytic leukemia/small lymphocytic lymphoma (n = 2); multiple myeloma (n = 1); mixed-cellularity Hodgkin lymphoma (n = 1); nodular sclerosis Hodgkin lymphoma (n = 1); aggressive B-cell lymphoma (n = 4); low-grade B-cell lymphoma (n = 4); lymphoblastic lymphoma, null cell type (n = 1); and precursor B-lymphoblastic lymphoma/leukemia (n = 1). More than half of the cases (17/32) were diagnosed on needle biopsy with immunophenotyping. Conclusions.-Although open lymph node biopsy is a preferred method for diagnosis, needle biopsy plays a significant role in this setting, and, coupled with other information such as flow cytometry and immunohistochemistry, it is considered a practical and reliable method.