# Pulmonary Intravascular Large B‐Cell Lymphoma Diagnosed by Transbronchial Lung Cryobiopsy: A Case Report

## TL;DR

A rare lung lymphoma was successfully diagnosed using a less invasive lung biopsy technique in a 68-year-old man.

## Contribution

This case highlights the utility of transbronchial lung cryobiopsy for diagnosing pulmonary IVLBCL.

## Key findings

- TBLC provided histopathologic confirmation of IVLBCL after other methods failed.
- Cryobiopsy allows evaluation of lung microvasculature, aiding in IVLBCL diagnosis.

## Abstract

Intravascular large B‐cell lymphoma (IVLBCL) is a rare and aggressive extranodal lymphoma characterised by the proliferation of malignant lymphocytes within the lumens of blood vessels. Diagnosing IVLBCL is often challenging due to its nonspecific clinical presentation and difficulty in obtaining histopathologic confirmation. Here, we present a case of IVLBCL diagnosed by transbronchial lung cryobiopsy (TBLC). A 68‐year‐old man was initially diagnosed with diffuse large B‐cell lymphoma based on an orchiectomy specimen. Although initial treatment achieved complete remission, tumour marker levels progressively increased during follow‐up. TBLC was performed after bone marrow biopsy, cerebrospinal fluid cytology, and a random skin biopsy failed to detect lymphoma lesions. Histological findings of the TBLC specimen demonstrated medium‐sized atypical lymphocytes filling the blood vessels, leading to a diagnosis of IVLBCL. Cryobiopsy specimens allow for the evaluation of alveolar structure and microvasculature, making it a valuable and less invasive diagnostic option for pulmonary IVLBCL.

Intravascular large B‐cell lymphoma (IVLBCL) is a rare and aggressive extranodal lymphoma characterised by the proliferation of malignant lymphocytes within the lumens of blood vessels. Diagnosing IVLBCL is often challenging due to its nonspecific clinical presentation and difficulty in obtaining histopathologic confirmation. Here, we present a case of IVLBCL diagnosed by transbronchial lung cryobiopsy (TBLC).