CXCR-4 -directed PET/CT examination in a case of marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma)

Background

Mucosa-associated lymphoid tissue lymphoma (MALT lymphoma) is an indolent B-cell non-Hodgkin lymphoma originating from post-germinal center marginal zone B cells. It typically arises in mucosal sites due to chronic antigenic stimulation from autoimmune disorders or persistent infections (e.g., Helicobacter pylori in gastric MALT lymphoma) [1]. It accounts for 5–8% of all B-cell lymphomas, and is the most common extra-nodal marginal zone lymphoma, with an annual incidence of 1–2 cases per 100000 [2]. Common sites include the stomach, salivary glands, ocular adnexa, lung (where it is known as bronchus-associated lymphoid tissue lymphoma), thyroid, and, less frequently, the skin or intestine. Approximately 35–50% of cases occur in the stomach.

Accurate staging remains challenging due to the diseaseʼs indolent nature and variable metabolic activity. While CT is the first-line imaging modality for staging, it cannot reliably differentiate MALT lymphoma from reactive hyperplasia or other low-grade lymphomas. Meanwhile, FDG PET/CT aids in detecting occult lesions and identifying transformation to aggressive lymphoma (e.g., diffuse large B-cell lymphoma) but it has limited sensitivity for low-volume or indolent disease [3].

A 60-year-old man was referred following a routine chest radiograph. The imaging revealed a pulmonary nodule in the right middle lobe. After lobectomy and lymph node sampling, histological analysis confirmed the lesion as pulmonary MALT lymphoma.

Publication History

Received: 06 March 2025

Accepted after revision: 14 August 2025

Article published online:
28 August 2025

• References

• 1 Isaacson PG, Du MQ. MALT lymphoma: from morphology to molecules. Nat Rev Cancer 2004; 4 (08) 644-653
• 2 Swerdlow SH, Campo E, Harris NL. et al. WHO classification of tumours of haematopoietic and lymphoid tissues. Revised 4^th ed. Lyon: IARC; 2017
• 3 Barrington SF, OʼDoherty MJ. Limitations of PET for imaging lymphoma. Eur J Nucl Med Mol Imaging 2003; 30 (Suppl. 1) S117-S127
• 4 Leithner D, Neri E, DʼAnastasi M. et al. ESR Essentials: imaging of lymphoma-practice recommendations by the European Society of Oncologic Imaging. Eur Radiol 2025; 35 (07) 4387-4394
• 5 Albano D, Bosio G, Camoni L. et al. Prognostic role of baseline 18F-FDG PET/CT parameters in MALT lymphoma. Hematol Oncol 2019; 37 (01) 39-46
• 6 Haug AR, Leisser A, Wadsak W. et al. Prospective non-invasive evaluation of CXCR4 expression for the diagnosis of MALT lymphoma using [⁶⁸Ga]Ga-Pentixafor-PET/MRI. Theranostics 2019; 9 (12) 3653-3658
• 7 Mayerhoefer ME, Raderer M, Lamm W. et al. CXCR4 PET/MRI for follow-up of gastric mucosa-associated lymphoid tissue lymphoma after first-line Helicobacter pylori eradication. Blood 2022; 139 (02) 240-244
• 8 Kosmala A, Duell J, Schneid S. et al. Chemokine receptor–targeted PET/CT provides superior diagnostic performance in newly diagnosed marginal zone lymphoma patients: a head-to-head comparison with [18F]FDG. Eur J Nucl Med Mol Imaging 2024; 51 (03) 749-755