[Biopsy diagnosis for gastric lymphoma--usefulness and limitation of AgNOR staining]

Sixteen cases of resected gastric lymphoma were classified into 3 groups based on the easiness of the diagnosis; mucosa associated lymphoid tissue lymphoma (MALToma) 4 cases, superficial type lymphoma 5 cases and ulcerative (mass forming) type lymphoma 7 cases. Sixty seven of pre-operative biopsy reports and 44 biopsy specimens were analyzed. Although lymphoma cells retrospectively obtained in 92%, 69% and 88% of biopsy specimens, the definite diagnosis was only made in 7%, 24% and 38% of endoscopic biopsy. Mean AgNOR number per nucleus in resected specimens were as follows; chronic inflammation 1.20 +/- 0.02, MALToma 1.39 +/- 0.23, superficial lymphoma 2.44 +/- 0.50 and ulcerative lymphoma 3.44 +/- 0.55. They correlated well to proliferating cell nuclear antigen positive rates (r = 0.776, p < 0.01). Supposing that lesions showing 2.0 or more AgNOR dots in biopsy specimens are lymphoma, diagnostic rate improves to 69% in superficial lymphoma and to 88% in ulcerative lymphoma. Biopsy specimens from MALToma never showed 2.0 or more AgNOR dots. These results suggest that application of AgNOR to the biopsy diagnosis is useful in superficial and ulcerative lymphoma and has limitation in MALToma of the stomach.