PMLBCL was classified as a distinct subtype of DLBCL initially by the Revised European and American Classification of Lymphoid neoplasms and in 2001 by the World Health Organization [
6,
7]. Epidemiologically, PMLBCL is more common in women than men and has a median age of 37 at presentation [
5]. Conversely, DLBCL often presents in the elderly population and commonly in men, making PMLBCL an entity relevant for the pregnant population and possibly an underreported scenario because of its relatively recent introduction into the lymphoma classification [
8].
The disease often presents as a bulky tumor in the mediastinum, causing compressive symptoms including dyspnea and superior vena cava syndrome. Pleural or pericardial effusions have been found at presentation in up to 50% of patients. While bone marrow infiltration is rare, extranodal sites may be involved in recurrent disease [
8]. PMLBCL arises from a population of thymic B cells and consists of medium-sized to large cells with an abundant pale cytoplasm and they are commonly associated with a delicate interstitial fibrosis. Immunohistochemistry of the cells shows the presence of B-cell antigens, including CD19, CD20, CD22, and CD79a, in addition to CD30 positivity in more than 80% of cases [
8]. While genomic profiling has allowed PMLBCL to be distinguished from DLBCL, it has also demonstrated similarities between the transcription profile of PMLBCL and Hodgkin lymphoma. Specifically, over one-third of all PMLBCL signature genes, including MAL, SNFT, TNFRSF6, TARC, and CD30, were found to be highly expressed in the Hodgkin lymphoma [
9].
The management of PMLBCL has been a longstanding matter of discussion. CHOP regimen has yielded poor results, with cure rates rarely surpassing 50–60% [
5]. Studies with more aggressive regimens as MACOP-B (methotrexate, cytarabine, cyclophosphamide, vincristine, prednisone, and bleomycin) followed by involved field radiation therapy demonstrated better results, with complete remission rates of 86% and overall survival (OS) and progression-free survival (PFS) rates of 86% and 91%, respectively, at nine years [
10]. However, the use of methotrexate during pregnancy should be discouraged because of the known teratogenic effects of the agent even in advanced stages of the pregnancy [
11]. One of the most promising approaches to PMLBCL has been the use of EPOCH regimen (etoposide, vincristine, doxorubicin, cyclophosphamide, and prednisone) with and without rituximab. Dunleavy et al. reported an OS of 100% and event-free survival (EFS) of 94% with EPOCH plus rituximab in 22 patients with PMLBCL [
12]. Unfortunately, the lack of evidence of etoposide in pregnancy limits the feasibility of this regimen in pregnant patients. Recently, R-CHOP regimen was used in 76 patients with PMLBCL and demonstrated to be superior to CHOP alone and comparable to more intensive chemotherapy regimens, with cure rates exceeding 82% and 5-year OS rates of 89% [
5]. In addition, a review of NHL treated during pregnancy with CHOP demonstrated that patients could be offered standard regimens with no evidence of adverse fetal events. Likewise, the addition of rituximab was not associated with higher incidence of fetal malformations [
13].
mmHg, but normal left-ventricular ejection fraction. Blood tests revealed normal blood counts and chemistry, but an elevated lactate dehydrogenase at 1627