CD30-Positive Anaplastic Variant of Diffuse Large B-cell Lymphoma: Frequency and Association With Clinicopathological Parameters

Abstract

Introduction Diffuse large B-cell lymphoma (DLBCL) is an aggressive B-cell lymphoma and is the most common type of non-Hodgkin's lymphoma (NHL) worldwide. The World Health Organization (WHO) classification of hematopoietic tumors has recognized three morphological variants of DLBCL: centroblastic, immunoblastic, and anaplastic. Some studies have shown that the anaplastic variant of DLBCL is associated with aggressive clinicopathological features. Anaplastic DLBCL is rare, and the clinicopathological characteristics of this subtype of DLBCL are not widely studied in our population. Therefore, in this study, we evaluated the frequency of the anaplastic variant of DLBCL and its association with other clinicopathological parameters. Methods A retrospective study was conducted in the Department of Histopathology at the Liaquat National Hospital and Medical College over a period of six years, from January 2015 to December 2020. All cases diagnosed as DLBCL based on morphology and immunohistochemical (IHC) profile were included in the study. The diagnosis of anaplastic DLBCL was rendered based on morphology (large bizarre pleomorphic cells in a cohesive or sheet-like growth pattern), combined with CD30 IHC expression. Results The mean age of the patients was 52.90 ±16.42 years, and the mean Ki67 index was 73.18 ±16.52%. Of the 220 cases of DLBCL, 47.3% cases were germinal center B-cell (GCB) subtype, and 59.1% cases were nodal. BCL-2, BCL-6, MUM1, c-MYC, and CD10 positivity were noted in 60%, 45.5%, 40.9%, 44.1, and 38.6% cases, respectively. Only 14 cases (6.4%) were recognized as anaplastic variants of DLBCL according to the previously defined criterion. The only significant association of anaplastic-variant DLBCL was noted with a lack of BCL-2 expression. No significant association of anaplastic-variant DLBCL was noted with age, gender, Ki67 index, DLBCL subtype, or any other IHC marker expression. Conclusion We found a low frequency of the anaplastic variant of DLBCL in our study. No significant association of this DLBCL variant was noted with any of the clinicopathological parameters, except for the lack of BCL-2 expression. Alternatively, from a pathological perspective, it is important to recognize this variant of DLBCL as it often mimics other CD30-positive lymphoma and undifferentiated carcinoma.

Concurrent Diffuse B-cell Lymphoma and Paraganglioma in a Red-tailed Boa (Boa constrictor constrictor) with Inclusion Body Disease

“…However, immunophenotyping confirmed that this boa's lymphoma more closely resembles the anaplastic variant of diffuse large B-cell lymphoma (Hashmi et al ., 2021) that is reported in humans and dogs (Valli et al ., 2016). Confirmation would require positive expression of CD30 and lack of expression of ALK (anaplastic lymphoma kinase); unfortunately, antibodies against both targets are unavailable in snakes (Valli et al ., 2016; Stranahan et al ., 2019; Hashmi et al ., 2021; Zhang et al ., 2022). Because the microscopic features of this snake's lymphoma are similar to DLBCL of humans and dogs, a similar diagnosis was made with the caveat that additional studies are needed to confirm that this type of tumor also represents a distinct entity in snakes.…”

“…The snake's lymphoma had pronounced anaplasia, which is a typical feature of a subtype of T-cell lymphoma reported in dogs and humans, an anaplastic large T-cell lymphoma (Stranahan et al, 2019;Zhang et al, 2022). However, immunophenotyping confirmed that this boa's lymphoma more closely resembles the anaplastic variant of diffuse large B-cell lymphoma (Hashmi et al, 2021) that is reported in humans and dogs (Valli et al, 2016). Confirmation would require positive expression of CD30 and lack of expression of ALK (anaplastic lymphoma kinase); unfortunately, antibodies against both targets are unavailable in snakes (Valli et al, 2016;Stranahan et al, 2019;Hashmi et al, 2021;Zhang et al, 2022).…”