Extranodal natural killer/T-cell lymphoma (nasal type) presenting as a perianal abscess: A case report

Figure 1 Colonoscopy images showing necrotic tissue and erosion at the edge of the anal margin (black arrows).

Figure 2 Histopathological examination showing moderate-severe acute and chronic inflammation with inflammatory necrosis and hyperplastic granulation tissue.

Figure 3 T2 liposuction magnetic resonance imaging demonstrated edema (A, yellow arrow) and enlarged lymph nodes (B, arrow) around the rectum on diffusion weighted imaging.

Figure 4 Histopathological and immunohistochemical examinations. A-C: Hematoxylin-eosin staining of tumor cells (A, 100× magnification, C, 400× magnification) and tumor-associated necrotic tissue (B, 100× magnification); D-J: immunohistochemical staining for CD2 (D), CD3 (E), CD56 (F), perforin (G), granzyme B (H), TIA-1 (I), and Ki-67 (J).

Figure 5 Positron emission tomography-computed tomography showing increased marker uptake in the kidneys (A) and nasopharyngeal area (B).

Figure 6 Small-to-moderate size lymphoid tissue hyperplasia with necrosis and apoptosis in nasal endoscopy biopsy.