Low-grade gastric B-cell lymphoma of mucosa-associated lymphoid tissue (MALT): a multifocal disease

Gastrectomy specimens from five patients following gastroscopic biopsies which showed low‐grade B‐cell lymphoma of mucosa‐associated lymphoid tissue (MALT) were examined by serially sectioning and paraffin wax embedding using a ‘swiss roll’ technique. This procedure allowed the construction of a map of the specimen on which the distribution of the lymphoma could be plotted. In each case confluent lymphoma was identified. In addition small foci of lymphoma consisting of 1–4 lymphoid follicles surrounded by neoplastic centrocyte‐like cells were seen. The positions of these ‘micro‐lymphomas’ were plotted on the gastrectomy maps, showing multiple foci distributed throughout the gastric mucosa. The identification of these microscopic lesions may explain the development of local relapse, often after a long disease‐free interval, in patients with gastric MALT lymphoma treated by partial gastrectomy where excision appears to have been complete. Patients treated in this way should, therefore, be followed‐up indefinitely, with regular endoscopy and gastric biopsy, in order to identify early local disease relapse.