Review of Respiratory Medicine - Volumen 25, N�mero 2 - June 2025

Original Articles

Primary Pulmonary Diffuse Large B-Cell Lymphoma: the Importance of Early Diagnosis

Linfoma pulmonar primario difuso de células grandes: la importancia del diagnóstico precoz

ABSTRACT

Primary pulmonary diffuse large B-cell lymphoma (PP-DLBCL) is a rare and aggres­sive form of extranodal non-Hodgkin lymphoma, with an exceptionally low incidence among pulmonary neoplasms. Early diagnosis is crucial, as the clinical course can be fulminant, especially in patients without prior immunosuppression. Through the analysis of a clinical case with an atypical presentation, we emphasize the importance of prompt recognition, efficient diagnostic approaches using minimally invasive techniques, and timely implementation of targeted therapies to improve prognosis. A comprehensive approach is proposed, spanning from clinical suspicion to therapeutic strategy, basing on both experience and recent evidence.

Key words: Primary pulmonary lymphoma, Diffuse large B-cell lymphoma, Thoracic oncology, Pulmonary neoplasms

RESUMEN

El linfoma pulmonar primario difuso de células grandes (LPP-DCG) representa una forma agresiva y poco frecuente de linfoma no Hodgkin extranodal, con una incidencia extre­madamente baja en el contexto de neoplasias pulmonares. Su diagnóstico temprano resulta fundamental, ya que la evolución clínica puede ser fulminante, especialmente en pacientes sin inmunosupresión previa. A través del análisis de un caso clínico de presentación atípica, se enfatiza la relevancia del reconocimiento precoz, el abordaje diagnóstico eficiente mediante técnicas mínimamente invasivas y la implementación oportuna de terapias específicas para mejorar el pronóstico. Se propone una perspec­tiva integradora, desde la sospecha clínica hasta la estrategia terapéutica, basada en la experiencia y en la evidencia reciente.

Palabras clave: Linfoma pulmonar primario, Linfoma difuso de células grandes B, Oncología torácica, Neoplasias pulmonares

Recibido: 12/10/2024

Aceptado: 03/08/2025

INTRODUCTION

Primary pulmonary lymphoma (PPL) represents a clinical challenge due to its low prevalence and nonspecific initial manifestations. It is defined as a lymphoid proliferation originating in the pulmo­nary parenchyma¹, without evidence of extrapul­monary involvement at the time of diagnosis or within the following three months. PPL accounts for less than 1% of pulmonary neoplasms, 3-4% of extranodal² non-Hodgkin lymphomas, and less than 1% of non-Hodgkin lymphomas in general. Among its histological variants, the diffuse large B-cell subtype (PP-DLBCL)³ has the worst prog­nosis, with aggressive clinical behavior, rapid dis­semination⁴, and limited possibilities of curative surgical treatment. This presentation is usually seen in older adults, often without a history of immunosuppression, and its diagnostic approach requires a high index of suspicion and multidisci­plinary coordination so as not to delay the start of treatment.

CASE REPORT

We present the case of a 72-year-old man, former smoker, with a history of two spontaneous pneumothoraces treated with talc pleurodesis. He presented with a two-week history of dyspnea, and productive cough. Chest CT scan revealed an obstructive mass in the intermediate bronchus, with associated atelectasis and mediastinal lymphadenopathy. (Figure 1).

Video bronchoscopy showed an infiltrative lesion in the intermediate bronchus, and biopsies revealed a diffuse large B-cell lymphoma. The plan included oncolo­gical treatment and the insertion of an endobronchial stent, but the patient developed hospital-acquired pneumonia, acute respiratory failure, and multiple organ failure, and died. This case highlights the rapid clinical deterioration in aggressive forms and the need for immediate diagnosis and treatment.

DISCUSSION

PP-DLBCL accounts for 11%-19% of PPL cases. Unlike MALT lymphoma (mucosa-associated lymphoid tissue lymphoma), which has an indo­lent course and excellent prognosis, PP-DLBCL is characterized by its biological aggressiveness, with early invasion of mediastinal and extrapul­monary structures, as well as frequent recur­rence. Excluding immunocompromised patients, the mean age of presentation is 60 years, with common respiratory symptoms such as dyspnea, cough, or chest pain, in addition to fever and weight loss.

Histologically, PP-DLBCL may derive from the transformation of low-grade lymphomas, par­ticularly MALT, although cytogenetic differences allow both entities to be distinguished. In some cases, this coexistence may occur in up to 50% of patients. It has been associated with immunosup­pression (HIV, transplants, use of cyclosporine or OKT3) and autoimmune diseases such as Sjögren’s syndrome.

From a diagnostic standpoint, chest CT usu­ally reveals parenchymal masses, with or without cavitation⁴; and bronchoscopy is essential for visualizing endobronchial lesions and obtaining biopsies. The development of techniques such as endobronchial ultrasound (EBUS) has shown high sensitivity and specificity for the identification and subclassification of thoracic lymphomas, according to Wang et al (2023)⁵. This minimally invasive technique allows a safe and accurate approach to histological diagnosis.

With regard to treatment, the combination of chemotherapy and immunotherapy has proven to be the most effective⁶. The CHOP regimen (cyclophosphamide, doxorubicin, vincristine, and prednisone) together with rituximab (anti-CD20) is the current standard of care. Surgical options play a very limited role, given the extent of disease at the time of diagnosis in most cases.

The median survival of PP-DLBCL ⁷ remains low, with only 3%-5% survival at 10 years, as opposed to 90% 5-year survival observed in MALT lymphoma. This fact reinforces the need to establish early suspi­cion algorithms and streamline diagnostic strategies to improve prognosis. In our case, multidisciplinary management made it possible to reach the diagnosis and plan the start of treatment in less than 15 days, despite subsequent complications.

CONCLUSION

Primary pulmonary large B-cell lymphoma is a rare but highly aggressive neoplasm ⁸, prompting diagnostic suspicion in the presence of respiratory conditions with suggestive imaging findings. Early diagnosis is crucial to initiate targeted therapies that may alter the course of the disease. The use of endoscopic tools and a multidisciplinary approach are key to ensuring timely diagnosis⁹. Coordination among pulmonologists, oncologists, and patholo­gists is essential to optimize therapeutic manage­ment and improve patient survival.

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