Recurrent primary cardiac lymphoma on aortic valve allograft: implications for therapy

Isolated cardiac valve involvement in smoldering adult T-cell leukemia/lymphoma

Adult T-cell leukemia/lymphoma (ATLL) is an aggressive mature T-cell neoplasm caused by infection with the Human T-cell Lymphotropic Virus Type 1 (HTLV-1). Cardiac involvement in patients with ATLL is infrequent, and when it happens it is usually seen in aggressive ATLL subtypes. However, ATLL presenting as isolated cardiac valve involvement is extremely rare. To date, only three histologically proven cases of ATLL with isolated cardiac valve involvement have been reported. Herein, we describe a 61-year-old Peruvian man who presented heart failure symptoms secondary to progressive cardiac valve infiltration. The patient underwent mitral valve replacement with a mechanical prosthesis. Histopathological evaluation of the resected valve revealed leaflet thickening with a nodular appearance due to fibrous tissue containing atypical T-lymphocytes with Foxp3 expression, infiltrating all layers of the resected valve. Interestingly, tumor cells were distributed around an incidental venous malformation (i.e., cavernous hemangioma). Postoperative evaluation demonstrated positive serology for HTLV-1, and a diagnosis of ATLL was established. Postoperative positron emission tomography/computed tomography did not show lesions outside the heart and cell blood counts were within normal range with low level of circulating CD4+ CD25+ lymphoma cell counts (7%); therefore, patient's disease was considered as smoldering ATLL and a "watch and wait" strategy was pursued. Currently, the patient is alive with no progression of disease after 18 months from diagnosis. Isolated cardiac valve involvement by ATLL should be considered in the differential diagnosis of HTLV-1 carriers with progressive heart failure, even when systemic lymphoma involvement is absent or not apparent.

B-cell lymphomas with discordance between pathological features and clinical behavior

B-cell lymphomas encompass a large number of disease entities clinically ranging from indolent to aggressive. The defining pathological features usually predict clinical course, with small and large B-cell lymphomas correlating to low-grade vs high-grade features, but discordant situations may be encountered. Two sessions of the workshop of the XVIII meeting of the European Association for Haematopathology (EAHP) held in Basel in 2016 addressed this topic. One session illustrated various facets of "aggressiveness" in indolent lymphomas, either peculiar clinical manifestations, cytological variants, or unusual genetic features, as well as several examples of progression or transformation to a more aggressive disease. Another session exemplified large B-cell lymphomas with unexpected indolent behavior including cases arising in well-defined body compartments or in sanctuary sites. This paper describes the features of the cases presented in both groups, highlights the most salient points of discussion raised by the submitters and the panel, and summarizes current knowledge and recommendations relevant to diagnostic pathology practice.

Silicone implants and lymphoma: The role of inflammation

The risk of hematological malignancies is mainly determined by genetic background, age, sex, race and ethnicity, geographic location, exposure to certain chemicals and radiation; along with the more recently proposed immune factors such as chronic inflammation, immunodeficiencies, autoimmunity, and infections. Paradigmatic examples include the development of lymphoma in Sjögren's syndrome and Hashimoto thyroiditis, gastric MALT lymphoma in Helicobacter pylori infection, or lymphomas associated with infections by Epstein-Barr virus, human herpes virus 8 (HHV 8) and leukemia/lymphoma virus 1 (HTLV-1). A growing number of reports indicates an increased risk of lymphoma, particularly of the anaplastic large cell (ALCL) type. The implants, specifically those used in the past, elicit chronic stimulation of the immune system against the prosthetic material. This is particularly the case in genetically susceptible hosts. We suggest that polyclonal activation may result in monoclonality in those at risk hosts, ultimately leading to lymphoma. We suggest that patients with an inflammatory response against silicone implants be monitored carefully.