Neoplastic and Autoimmune Comorbidities in Patients with Primary Cutaneous B-Cell Lymphoma

Primary cutaneous B-cell lymphomas (PCBCLs) constitute a rare subset of non-Hodgkin lymphoma (NHL), with distinctive clinical and biological characteristics. The risk of autoimmune or neoplastic comorbidities in subjects with NHL has been extensively reported in the literature, but the data available are not directly applicable to PCBCLs. The aim of our study was to determine the frequency of relevant medical conditions, with a primary focus on autoimmune and neoplastic disorders, in subjects with PCBCL. We performed a retrospective observational study involving 56 patients diagnosed histologically with PCBCL and 54 sex- and age-matched controls. Our results show a statistically significant association for neoplastic comorbidities in general (41.1% vs. 22.2%, p = 0.034) and hematological malignancies specifically (19.6% vs. 1.9%, p = 0.0041) with PCBCL compared to controls. We did not highlight a statistically significant difference in the frequency of autoimmune comorbidities (21.4% vs. 9.3%, p = 0.1128) and of chronic viral hepatitis (7.1% vs. 0, p = 0.1184). Finally, type 2 diabetes (19.6% vs. 1.9%, p = 0.0041) was significantly associated with PCBCL. Our preliminary data supporting the association between PCBCLs and neoplastic disorders suggest that altered immune surveillance may be a common predisposing mechanism.