title: Type II EATL (epitheliotropic intestinal T-cell lymphoma): a neoplasm of intra-epithelial T-cells with predominant CD8αα phenotype.
abstract: In this multicentre study, we examined 60 cases of Type II enteropathy-associated T-cell lymphoma (EATL) from the Asia-Pacific region by histological review, immunohistochemistry and molecular techniques. Patients were mostly adult males (median age: 58 years, male:female 2.6:1), presenting with abdominal pain (60%), intestinal perforation (40%) and weight loss (28%). None had a history of coeliac disease and the median survival was only 7 months. Histologically, these tumours could be divided into (i) central tumour zone comprising a monotonous population of neoplastic lymphocytes, (ii) peripheral zone featuring stunted villi and morphologically atypical lymphocytes showing epitheliotropism, and (iii) distant mucosa with normal villous architecture and cytologically normal intra-epithelial lymphocytes (IELs). Characterized by extensive nuclear expression of Megakaryocyte-associated tyrosine kinase (MATK) (87%) and usually a CD8(+)CD56(+) (88%) cytotoxic phenotype, there was frequent aberrant expression of CD20 (24%). T-cell receptor (TCR) expression was silent or not evaluable in 40% but of the remainder, there was predominant expression of TCRαβ over TCRγδ (1.6:1). In keeping with the normal ratio of IEL subsets, CD8(+) cases showed predominant CD8αα homodimer expression (77%), regardless of TCR lineage. These tumours constitute a distinct entity from classical EATL, and the pathology may reflect tumour progression from IEL precursors, remnants of which are often seen in the distant mucosa.
authors: Department of Pathology, Singapore General Hospital, Singapore, Singapore. drtansy@gmail.com
authors: S-Y
authors: SY
authors: Tan
authors: S-S
authors: SS
authors: Chuang
authors: T
authors: T
authors: Tang
authors: L
authors: L
authors: Tan
authors: Y-H
authors: YH
authors: Ko
authors: K-L
authors: KL
authors: Chuah
authors: S-B
authors: SB
authors: Ng
authors: W-J
authors: WJ
authors: Chng
authors: K
authors: K
authors: Gatter
authors: F
authors: F
authors: Loong
authors: Y-H
authors: YH
authors: Liu
authors: P
authors: P
authors: Hosking
authors: P-L
authors: PL
authors: Cheah
authors: B-T
authors: BT
authors: Teh
authors: K
authors: K
authors: Tay
authors: M
authors: M
authors: Koh
authors: S-T
authors: ST
authors: Lim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000954:Antigens, Surface / Q000378:metabolism; D016827:CD8 Antigens / Q000378:metabolism*; D058527:Enteropathy-Associated T-Cell Lymphoma / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism* / Q000628:therapy; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010641:Phenotype; D011379:Prognosis; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D055815:Young Adult
chemical_list: D000954:Antigens, Surface; D016827:CD8 Antigens; C409469:CD8 antigen, alpha chain; D016271:Proto-Oncogene Proteins c-myc; D011948:Receptors, Antigen, T-Cell