Table 6 Pathological features of human digestive T-cell lymphoma [25, 153, 164, 165, 175, 176]

Indolent digestive T-cell lymphoproliferative disease

Diarrhoea, abdominal pain

- Crypt hyperplasia, variable degrees of villous atrophy

- Non-destructive superficial infiltrate of small uniform T-cells mostly lamina propria-based

- Infiltration into submucosa observed in some cases

- No evident major epitheliotropism

CD3+, CD8+ or CD4+, CD2+, CD5+/−, CD7+/−, CD30-, CD56-, TCRαβ+

Indolent chronic relapsing course

Enteropathy associated T-cell lymphoma (EATL)

Overt or silent gluten-sensitive enteropathy

- Crypt hyperplasia, villous atrophy

- Pleomorphic medium- to large-sized neoplastic lymphocytes with transmural infiltration

- Presence of other mixed inflammatory cells such as histiocytes and eosinophils

- Intraepithelial lymphocytosis present in non-tumoral mucosa and in epithelium distant from the main mass

CD3+, CD5-, CD8−/+, CD56-, CD103+, often CD30+, cytotoxic phenotype +/−, TCR αβ + (usually)

Aggressive

Monomorphic epitheliotropic T-cell lymphoma

Occurs without a history of coeliac disease

- No crypt hyperplasia, possible villous atrophy

- Monomorphic infiltrate with epitheliotropism

- Transmural infiltration

- No associated inflammatory background

CD3+, CD5-, CD4-, CD8+, CD56+, cytotoxic phenotype, CD30-, TCR γδ + (usually)

Aggressive