Follicle Center Lymphoma (FCL) of the Lower Female Genital Tract (LFGT): A Novel Variant of Primary Cutaneous Follicle Center Lymphoma (PCFCL)

Primary cutaneous follicle center lymphoma has been distinguished from nodal follicular lymphoma (FL) based on genomic and clinical features. The nature of other extranodal FLs is not well defined. We report 15 cases of follicle center lymphoma involving the lower female genital tract. Cases were evaluated using an immunohistochemical panel for B-cell lymphoma, B-cell clonality, fluorescence in situ hybridization for BCL2 gene rearrangement, and next-generation sequencing. All patients had localized disease with no evidence of bone marrow involvement. Most cases (12/15, 80%) had a follicular pattern, at least focally. Large centrocytes were a prominent feature leading to concern for diffuse large B-cell lymphoma by referring pathologists. Neoplastic cells were positive for CD20 and BCL-6, while BCL-2 was positive in 2/15 (13%) cases. Fluorescence in situ hybridization for BCL2 gene rearrangement was negative in 10/11 (91%) cases. Next-generation sequencing performed in 10 cases revealed TNFRSF14 as the most frequently mutated gene in 6/10 (60%) cases. No case had CREBBP or KMT2D mutations as seen in nodal FL. None of the patients had progressive disease with durable complete remission achieved in 10/12 (83%) cases. The median follow-up period was 7.8 years (range: 0.2 to 20.5 y) with a 5-year overall survival of 100%. We conclude that follicle center lymphoma of the lower female genital tract is a novel variant of primary cutaneous follicle center lymphoma. Despite a frequent component of large cells, it is characterized by localized disease and low risk for dissemination. Awareness and recognition are important to distinguish these lesions from aggressive B-cell lymphomas.

The Multifaceted Role and Utility of MicroRNAs in Indolent B-Cell Non-Hodgkin Lymphomas

Normal B-cell development is a tightly regulated complex procedure, the deregulation of which can lead to lymphomagenesis. One common group of blood cancers is the B-cell non-Hodgkin lymphomas (NHLs), which can be categorized according to the proliferation and spread rate of cancer cells into indolent and aggressive ones. The most frequent indolent B-cell NHLs are follicular lymphoma and marginal zone lymphoma. MicroRNAs (miRNAs) are small non-coding RNAs that can greatly influence protein expression. Based on the multiple interactions among miRNAs and their targets, complex networks of gene expression regulation emerge, which normally are essential for proper B-cell development. Multiple miRNAs have been associated with B-cell lymphomas, as the deregulation of these complex networks can lead to such pathological states. The aim of the present review is to summarize the existing information regarding the multifaceted role of miRNAs in indolent B-cell NHLs, affecting the main B-cell subpopulations. We attempt to provide insight into their biological function, the complex miRNA-mRNA interactions, and their biomarker utility in these malignancies. Lastly, we address the limitations that hinder the investigation of the role of miRNAs in these lymphomas and discuss ways that these problems could be overcome in the future.

Cutaneous follicle center lymphomas with plasmacytic differentiation

Follicle center lymphomas, including primary cutaneous follicle center lymphoma (PCFCL), may rarely show plasmacytic differentiation. Such cases can pose a diagnostic challenge and can be mistaken for other lymphomas that more commonly include plasma cells. Here, we report four cases of PCFCL and one case of systemic follicular lymphoma involving the skin with associated monotypic plasma cells, including the clinical, morphologic and immunophenotypic features.

Repeated courses of low-dose 2 × 2 Gy radiation therapy in patients with indolent B-cell non-Hodgkin lymphomas

Purpose

In patients with indolent B‐cell non‐Hodgkin's lymphoma (B‐NHL), one course of low‐dose radiotherapy (LD‐RT) 2 × 2 Gy is emerging as new option of therapy in palliative setting. Efficacy of LD‐RT when repeated remains to be determinate. This study aims to assess the efficacy of repeated LD‐RT given in patients with indolent B‐NHL.

Materials and Methods

All consecutive adult patients who received two or more courses of LD‐RT 2 × 2 Gy for indolent B‐NHL at Gustave Roussy institution, during the period 1990‐2015 were retrospectively investigated.

Results

Thirty‐three patients received two or more courses of LD‐RT for indolent B‐NHL during the study period. The median age was 57 (range 37‐80) years, histological types were distributed among follicular lymphoma (n = 24 pts; 73%), marginal‐zone lymphoma (n = 6 pts; 18%), and primary cutaneous follicle center lymphoma (n = 3 pts; 9%). The median number of low‐dose radiation therapy courses given per patients was 2 (range 2‐6). The overall response rates following the first and the second course of LD‐RT were 96% and 88%, respectively (P = .31). The 1‐ and 2‐years local control rates following the first courses of LD‐RT were 94% (CI 95: 86‐100) and 94% (CI 95: 86‐98); and were 91% (CI 95: 82‐100) and 88% (CI 95: 77‐100) following the second course of LD‐RT (P = .39).

Conclusion

The repeated courses of LD‐RT offered similar efficacy compare with the first course in patients with indolent B‐NHL. LD‐RT repeated is a simple, easy to give, and non‐toxic asset that could be investigated as treatment option in patients with indolent B‐NHL.

Primary cutaneous B-cell lymphomas: part II. Therapy and future directions

The choice of therapy for primary cutaneous B-cell lymphoma (PCBCL) relies on correct histopathologic classification and the exclusion of systemic disease. In part II of this continuing medical education article, we will review the available therapies for the different types of PCBCL. Primary cutaneous follicle center lymphoma (PCFCL) and primary cutaneous marginal zone lymphoma (PCMZL) are indolent tumors with an excellent prognosis. They are managed similarly with local therapy, such as radiotherapy or surgical excision, for isolated disease and observation for asymptomatic multifocal presentations. Relapses are common in both PCFCL and PCMZL, but overall survival remains excellent. Primary cutaneous diffuse large B-cell lymphoma (both leg type and other) has a much poorer prognosis than indolent PCBCL, and it often requires an aggressive approach with radiation therapy and/or multiagent chemotherapy. Investigational approaches hold promise for the treatment of these malignancies, particularly primary cutaneous diffuse large B-cell lymphoma.

Primary cutaneous B-cell lymphomas: part I. Clinical features, diagnosis, and classification

Primary cutaneous B-cell lymphomas (PCBCLs) are defined as lymphomas with a B-cell phenotype that present in the skin without evidence of systemic or extracutaneous disease at initial presentation, after adequate staging. In non-Hodgkin lymphomas, the skin is the second most common site of extranodal involvement after the gastrointestinal tract. PCBCLs are histologically very similar to their nodal counterparts, and these histologic similarities can lead to confusion about both therapy and prognosis. This article will summarize the clinical, pathologic, and diagnostic features of the 3 main types of PCBCL: primary cutaneous follicle center lymphoma, primary cutaneous marginal zone lymphoma, and primary cutaneous diffuse large B-cell lymphoma, leg-type, and the appropriate evaluation and staging procedures for each of these entities.