![Fig. 2. BCL-2 immunostaining of neoplastic lymphoid tissue. / (A) In a low-grade MALT lymphoma, BCL-2 is expressed by the diffuse neoplastic infiltrate lying beneath the intestinal mucosa (Muc). BCL-2 is absent from reactive germinal centers (asterisks) in the tumor and from areas of high-grade transformation. The high-power view (bottom) shows the border between a low-grade area and a high-grade area. The arrows indicate large BCL-2–negative neoplastic cells. Original magnification top, × 200; bottom, × 800. (B) A pseudonegative follicular lymphoma in which the cells in a neoplastic follicle (Foll) lack BCL-2. However, a higher-power examination of the boxed area (center and bottom) shows that many of the BCL-2–positive small interfollicular cells (arrows) are neoplastic centrocytes (small cleaved cells). (Alkaline phosphatase–antialkaline phosphatase [APAAP] technique in paraffin sections; reproduced with permission from American Journal of Pathology47.) Original magnification top, × 250; center, × 400; bottom, × 800.](https://ash.silverchair-cdn.com/ash/content_public/journal/blood/99/2/10.1182_blood.v99.2.409/6/h80222021002.jpeg?Expires=1736045763&Signature=ry2M6WUlqTyBVzI5ieqFflTAmkmiejfnVUDJLTqpQ9hgJX3p2P8SePLR-np0HFGr~eNTpawh0w8JbQkbRYCHlJmXCgBav1pZcxKTHNJr-u9ipbJWwYZBm~hnNyEgiZF-GFBHAbrDvtTlkAs-iD5X6hY~3sPZFuK-M6Np85yntCrW7p2oxSEG2167~~4BwfqCEdvfDiG06F2sgZUcZwXz3PWTIJ8mxIkTOqUN3FpLfiycuMEYQrRxGLApo4uz1q0avv8iXwT0vL-AOXhltYcxuu3j9Yz2CIIXTl89KLJiyvntBWRl-Y4ug4AAYUFg9s3raa42bpuG6RW6kvbDJsZeiA__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
BCL-2 immunostaining of neoplastic lymphoid tissue.
(A) In a low-grade MALT lymphoma, BCL-2 is expressed by the diffuse neoplastic infiltrate lying beneath the intestinal mucosa (Muc). BCL-2 is absent from reactive germinal centers (asterisks) in the tumor and from areas of high-grade transformation. The high-power view (bottom) shows the border between a low-grade area and a high-grade area. The arrows indicate large BCL-2–negative neoplastic cells. Original magnification top, × 200; bottom, × 800. (B) A pseudonegative follicular lymphoma in which the cells in a neoplastic follicle (Foll) lack BCL-2. However, a higher-power examination of the boxed area (center and bottom) shows that many of the BCL-2–positive small interfollicular cells (arrows) are neoplastic centrocytes (small cleaved cells). (Alkaline phosphatase–antialkaline phosphatase [APAAP] technique in paraffin sections; reproduced with permission from American Journal of Pathology47.) Original magnification top, × 250; center, × 400; bottom, × 800.
