Table 7.

Comparison of different types of T and NK cell lymphoproliferative disorders and lymphomas involving the gastrointestinal tract (GIT).

	Indolent T-cell lymphoma of the GIT	Indolent NK-cell LPD of the GIT	Enteropathy-associated T-cell lymphoma	Monomorphic epitheliotropic intestinal T-cell lymphoma	Extranodal NK/T-cell lymphoma
Major clinical presentation	Abdominal symptoms	Asymptomatic or nonspecific GI symptoms	Abdominal symptoms; bowel perforation or obstruction common.	Abdominal symptoms; bowel perforation or obstruction common.	Abdominal symptoms; bowel perforation common.
Association with celiac disease	–	–	+	–	–
Clinical course	Chronic persistent or relapsing	Usually spontaneous regression, but may persist or develop new lesions	Aggressive	Aggressive	Aggressive
Commonest localization in GIT	Small bowel or colon	Stomach, small and large intestines	Small intestine	Small intestine	Small and large intestines
Depth of involvement	Superficial	Superficial	Deep	Deep	Deep
Cytomorphology	Small lymphoid cells with minimal nuclear atypia	Atypical medium-sized cells with pale cytoplasm and eosinophilic granules	Pleomorphic large or medium-sized cells, often with prominent inflammatory background	Monomorphic small to medium-sized cells	Variable cytomorphology, from small to medium-sized to large cells
Epitheliotropism	−/ focal	−/ minimal	+	+	–
Necrosis	–	–	+/−	Usually –	+
EBV association	–	–	–	–	+
Lineage	T cell, CD4+ >CD8+	NK cell	T cell, most often CD4-, CD8-	T cell, most often CD8+	NK cell (commoner) or T cell
Molecular genetics	JAK2::STAT3 fusion; mutations of JAK-STAT pathway genes and epigenetic modifier genes	JAK3 mutation	Gains of 9q34; loss of 16q12; mutations of JAK-STAT pathway genes (commonly JAK1, STAT3)	Gains of 9q34; loss of 16q12; mutations of SETD2 and JAK-STAT pathway genes (commonly JAK3, STAT5B)	6q21-25 deletion; Mutations of JAK-STAT pathway genes, epigenetic regulators, tumor suppressor genes (TP53, MGA) and RNA helicase (DDX3X)