# From CT to Microscopy: Radiological–Histopathological Correlation for Understanding Abdominal Lymphomas

## TL;DR

This study links CT scan features with histopathological types of abdominal lymphomas to improve diagnosis and treatment understanding.

## Contribution

The study is the first to correlate CT morphological and functional features with histopathological types of abdominal lymphomas.

## Key findings

- Enlarged lymph nodes were more common in indolent B NHL, while GI wall thickening and masses were more frequent in aggressive B NHL.
- GI tract lymphomas showed the highest CT postcontrast enhancement, and T-cell lymphomas enhanced more than B-cell lymphomas.
- Aggressive B-cell lymphomas were larger at diagnosis and more likely to be extranodal.

## Abstract

A computed tomography (CT) scan is the modality of choice for management of abdominal lymphomas. So far, CT morphological (location/origin and morphological appearance) and functional (post-contrast enhancement) characteristics have not been investigated in correlation with histopathological diagnosis, which was the aim of our study. The study revealed enlarged lymph nodes were a slightly more common CT morphological appearance in the indolent B non-Hodgkin lymphoma (NHL) group, while gastrointestinal (GI) wall thickening and organ and cavity solid masses/infiltrates were more frequent in the aggressive B NHL group. CT postcontrast enhancement showed lymphomas originating from the gastrointestinal tract had the highest enhancement, while histopathological characteristics showed that rare T-cell lymphoma enhancement was more pronounced compared to that of B-cell lymphoma. Our results might help in understanding the biological behavior of lymphomas, which can lead to earlier and more comprehensive diagnosis and treatment.

Background: Non-Hodgkin lymphomas (NHLs) are a heterogeneous group of indolent or aggressive lymphoproliferative neoplasms arising from lymph nodes or in extranodal locations. Computed tomography (CT) is the imaging modality of choice, while the definitive diagnosis is confirmed by analyzing tissue samples. The aim of this study was to determine the correlation between CT characteristics and histopathological types of abdominal lymphomas. Methods: A retrospective cross-sectional study included 119 patients with histopathologically confirmed abdominal lymphomas who underwent CT of the abdomen and pelvis prior to treatment. The following CT parameters were extracted: morphological presentation (enlarged lymph nodes/conglomerates, solid mass/masses, gastrointestinal wall thickening, abdominal organ involvement, intra- and extraperitoneal infiltrates), location, two-dimensional size, propagation if present, and postcontrast enhancement. Results: Enlarged lymph nodes were a slightly more common CT morphological appearance in the indolent B NHL group, while gastrointestinal (GI) wall thickening, solid masses, and infiltrates were more frequent in the aggressive B NHL group (p = 0.0256). Aggressive B-cell lymphomas had larger size at time of diagnosis compared to other types (p = 0.0436). CT postcontrast enhancement showed lymphomas originating from the gastrointestinal tract, which presented as wall thickening, had the highest enhancement (p = 0.0065 and p = 0.0485). Conclusions: Observed differences in abdominal lymphomas’ histopathological and imaging characteristics including location/origin, CT morphological appearance, and postcontrast enhancement revealed that extranodal lymphomas were more often of the aggressive B-cell type, aggressive B-cell types were larger, and GI tract lymphomas showed the most prominent enhancement. These findings can help in the diagnostic process and enable better management of lymphomas.