[Value of immunohistochemistry with paraffin in malignant lymphoma of the lymphoid tissue associated to the mucosa (MALT) of the digestive tract. Apropos of 8 cases with complete review of the literature].

The authors report eight cases of MALT malignant lymphomas arising in the stomach in four cases, small intestine in two cases and salivary glands in two cases. The gastric lymphomas presented in the form of persistent epigastric pain sometimes lasting for several years, in patients with a mean age of 50.5 years. Gastroscopy revealed recurrent ulcerations in two cases and ulcerated or ulcero-fungating tumours in two cases. The two patients with alpha heavy chain disease, both 21 years of age, presented with chronic diarrhoea. The endoscopic appearance consisted of a pseudopolypoid tumour in one case and a mosaic appearance in the other case. The two salivary gland lymphomas involved the submandibular gland in two patients aged 30 years and 50 years. They presented in the form of nodules 1 and 2 cm in diameter, first detected by the patients two months and four months previously. Histological examination demonstrated the presence of typical lesions of MALT lymphoma with, in particular, the presence of constant lympho-epithelial lesions, various forms of centrocyte-like proliferation, varying degrees of plasma cell differentiation, reactive or residual lymphoid follicles in five cases, which were detected on biopsies in three cases. Immunohistochemistry confirmed the monoclonal nature of the tumour in seven cases, i.e. 87.5% of cases. The application of DBB42 and DNA7 antibodies onto paraffin sections demonstrated the absence of DNA7 labelling of CCL in line with Isaacson's findings in favour of the hypothesis of a non-centrofollicular origin of maltomas. Finally, we observed a single case of recurrence in a women with incomplete resection of the primary gastric tumour.