Splenic Marginal Zone Lymphoma With Histological Transformation to Hodgkin's Lymphoma.

Marginal zone lymphoma (MZL) is a rare, slow-growing/indolent B cell lymphoid neoplasm accounting for 10.5% to 11.8% of all B cell lymphomas. MZL originates from the mature B lymphocytes, which are usually present in the marginal zone of the lymphoid follicle. Histological transformation (HT) is defined as sheets of large cells arising in an indolent lymphoma with morphological and immunophenotypic changes suggestive of a high-grade lymphoma such as Hodgkin's lymphoma, diffuse large B cell lymphoma (DLBCL), or Burkitt lymphoma. The median time of transformation ranges from one year to 15 years following the initial diagnosis of MZL. Studies reported that the deletion of TP53 and 7q and mutations in NOTCH2 are commonly associated with HT in MZL. This case report outlines the rare happening of an MZL transformation into a nodular subtype of Hodgkin's lymphoma in a 56-year-old female, which prompted further investigations and a different therapeutic approach. By reporting this case, we emphasize that HT changes the natural history and significantly affects the overall survival of patients with MZL. Hence, it is necessary to get a core needle or excisional biopsy whenever there is a clinical suspicion of HT in MZL for early diagnosis and a better therapeutic approach.