Enteropathy-Type T-Cell Lymphoma

AJCP / SHP/EAHP WORKSHOP Enteropathy-Type T-Cell Lymphoma Andreas Zettl, MD, 1 Ron deleeuw, 2 Eugenia Haralambieva, MD, 1 and Hans-Konrad Mueller-Hermelink, MD 1 Key Words: Enteropathy; Celiac disease; T-cell lymphoma; Intestine; Comparative genomic hybridization; 9q33-q34 gains Abstract Session 7 of the Society for Hematopathology/European Association for Haematopathology Workshop was devoted to case presentations and discussion of enteropathy-type T-cell lymphoma (ETL) and other T-cell lymphomas involving the gastrointestinal tract. ETL is a rare type of T-cell lymphoma, often associated with a history of celiac disease, that usually arises in the jejunum but can involve other gastrointestinal tract sites (eg, stomach and colon). As the cases submitted illustrate, there are 2 histologic groups of ETL that correlate with clinical and immunophenotypic features. Pleomorphicanaplastic ETL is usually associated with a history of celiac disease and histologic evidence of enteropathy and is most often CD56. Monomorphic ETL often occurs without a history of celiac disease, has variable histologic evidence of enteropathy, and is usually CD56+. Comparative genomic hybridization has shown recurrent chromosomal gains and losses that are characteristic of ETL and uncommon in other T-cell lymphomas, providing useful ancillary data for the diagnosis of ETL. Enteropathy-type T-cell lymphoma (ETL), also known as intestinal T-cell lymphoma and enteropathy-associated T-cell lymphoma, is a primary extranodal T-cell lymphoma arising in the intestine with intraepithelial T cells postulated as the cells of origin. 1 ETL was first characterized as a celiac disease associated neoplasm in 1978 by Isaacson and Wright, 2 and Isaacson et al 3 later demonstrated a T-cell derivation for this neoplasm. In 1986, O Farrelly et al 4 coined the term enteropathy-associated T-cell lymphoma owing to the close association of this lymphoma with villous atrophy of the jejunal mucosa adjacent to ETL. ETL is a very rare T-cell lymphoma that accounts for fewer than 5% of all gastrointestinal tract lymphomas, with most lymphomas involving the gastrointestinal tract being of B-cell lineage. The median age of patients with ETL at time of diagnosis is 60 years. Men and women are affected with similar frequency. 1 ETL most commonly arises in the proximal jejunum and less frequently elsewhere in the small intestine, stomach, or colon. Approximately 40% of patients seek care because of an acute abdomen owing to intestinal obstruction and/or tumor perforation with acute peritonitis requiring emergency surgery. Septicemia due to acute peritonitis accounts for the dismal clinical prognosis in these cases. In patients without intestinal perforation at diagnosis, common clinical symptoms are abdominal pain, weight loss, malabsorption, and proteinlosing enteropathy. At disease manifestation, approximately two thirds of ETL cases are limited to the gastrointestinal tract and mesenteric lymph nodes. In the course of the disease, dissemination can occur, with spread to the liver, spleen, skin, and other organs. 1 The clinical course of ETL is highly aggressive. In the series of 35 ETL cases reported by Daum et al, 5 only 28% of the patients were alive after a 2-year Downloaded from https://academic.oup.com/ajcp/article-abstract/127/5/701/1759953 Am J Clin Pathol 2007;127:701-706 701 701 701

Zettl et al / ENTEROPATHY-TYPE T-CELL LYMPHOMA follow-up. In a series of 31 cases reported by Gale et al, 6 a similarly poor clinical outcome was reported. ETL shows a striking association with celiac disease, suggesting that chronic stimulation of intraepithelial lymphocytes by nutritional gluten may be an important factor in lymphomagenesis (reviewed by Isaacson and Du 7 ). ETL and celiac disease share histologic features and the characteristic pattern of gut involvement. Furthermore, ETL and celiac disease arise in patients with similar HLA haplotypes. Clinically, the association of ETL with celiac disease is variable: (1) In a minority of patients, ETL is a complication of long-standing, clinically diagnosed celiac disease. (2) More frequently, there is a short history of malabsorption lasting weeks to months, clinically similar in manifestation to celiac disease. However, in these cases, the clinical symptoms may already be due to lymphoma rather than to celiac disease alone. (3) In a substantial proportion of cases, there is no clear-cut history of malabsorption; however, the resection specimen adjacent to invasive tumor shows increased intraepithelial lymphocytes with villous atrophy and crypt hyperplasia, features similar to celiac disease. In a small subset of patients, no signs of malabsorption and/or histologic enteropathy are seen. Macroscopically, ETL frequently manifests as multifocal gastrointestinal ulcers or deceptively bland intestinal perforations. The mucosa adjacent to the lesions may appear thickened or completely normal; villous blunting may be evident. Histologically, ETLs display highly variable features. Chott et al 8,9 classified ETL into 2 types: (1) small to mediumsized cell type, comprising pleomorphic small cell lymphoma and monomorphic small to medium-sized cell lymphoma; and (2) large cell ETL, comprising pleomorphic medium and large cell lymphoma, immunoblastic lymphoma, and anaplastic large cell lymphoma. However, recent novel data on the immunophenotype and genetics of ETL suggest that morphologic classification of ETL, by itself, is of lesser importance. 9,10 Genetically, ETLs, irrespective of their morphologic, immunophenotypic, and clinical variability, are rather homogeneous and highly distinct from other T-cell lymphoma entities. 10 Recent genetic characterization of ETL by conventional comparative genomic hybridization (CGH) has shed new light on the pathogenesis of these tumors. In a series of 38 ETLs characterized by CGH, recurrent chromosomal gains of 9q, 7q, 5q, and 1q and recurrent losses of 8p, 13q, and 9p were detected. 10 This series has meanwhile been extended to 72 cases of ETL (partially published, Zettl et al 10 ) Image 1. By conventional CGH, the most eminent chromosomal alteration is gain of 9q33-q34 observed in 46 (64%) of 72 ETLs. Additional recurrent chromosomal gains observed in ETL include 1q32 in 19 cases (26%), 5q35 in 15 (21%), 7q22 in 22 (31%), and 8q24 in 13 (18%). Recurrent chromosomal losses observed in ETL include 8p22-p23 in 15 cases (21%), 9p21 in 11 (15%), 13q22 in 18 (25%), and 18q22 in 13 (18%). Chromosomal gains on 9q33-q34 characterize ETL and are only rarely detectable in other types of peripheral T-cell lymphomas. 11-14 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 X Y Image 1 Chromosomal imbalances in enteropathy-type T-cell lymphoma (ETL). Conventional comparative genomic hybridization analysis of 72 cases shows recurrent chromosomal gains (bars on the right side of chromosomal ideograms) and losses (bars on the left). The most eminent chromosomal alteration was gain of 9q33-q34 observed in 46 (64%) of 72 ETL cases. Further recurrent chromosomal gains in ETL were observed on 1q32 (26%), 5q35 (21%), 7q22 (31%), 8q24 (18%), and recurrent losses were observed on 8p22-p23 (21%), 9p21 (15%), 13q22 (25%), and 18q22 (18%). 702 Am J Clin Pathol 2007;127:701-706 Downloaded 702 from https://academic.oup.com/ajcp/article-abstract/127/5/701/1759953

AJCP / SHP/EAHP WORKSHOP Furthermore, similar genetic chromosomal imbalances were observed in primary gastric and colonic T-cell lymphoma, not otherwise specified, suggesting a close genetic relationship between gastrointestinal T-cell lymphomas at either location and ETL.10 During the Workshop, cases showing the entire spectrum of ETL were presented, with 4 cases of CD56+ ETL Image 2 and 8 cases of CD56 ETL Image 3. In addition, several cases raised particular issues around the diagnosis of ETL. Case 236 was a CD56 ETL that was immunophenotyped by flow cytometry of endoscopic biopsy specimens. Case 23 was a CD56 ETL with large cell transformation manifesting in an inguinal lymph node. Case 200 was a case of CD56 ETL diagnosed in ascites fluid. Case 140 was a case of gastric Tcell lymphoma with an immunophenotype typical of ETL, raising the question about the classification of ETL outside the small intestine. Case 98 was a case of refractory celiac disease in which the intraepithelial lymphocytes had an aberrant immunophenotype, raising the question about the boundary between refractory celiac disease and overt ETL. Cases were also submitted to the Workshop that were classified as peripheral T-cell lymphoma (PTCL) involving the gastrointestinal tract but did not clearly fit within the spectrum of ETL. Case 103 was classified by the panel as a γδ PTCL involving the gastrointestinal tract. Case 121 was a composite lymphoma, diffuse large B-cell lymphoma and A B C D Image 2 (Case 62) Typical example of a CD56+ enteropathy-type T-cell lymphoma (ETL). These neoplasms commonly show monomorphic small to medium-sized tumor cells, frequently accompanied by infiltration of the overlying intestinal epithelium (A, H&E, 100). In this type of ETL, the neoplastic cells are positive for CD3 (B, 40) and commonly express CD8 (C, 40) and CD56 (D, 40). Contributed by R. Gascoyne. Am J Clin Pathol 2007;127:701-706 Downloaded from https://academic.oup.com/ajcp/article-abstract/127/5/701/1759953 703 703 703

Zettl et al / ENTEROPATHY-TYPE T-CELL LYMPHOMA PTCL. Case 142 was a unique case of PTCL expressing CD30 and CD15. Case 28 was a peculiar atypical natural killer cell proliferation in the gastrointestinal tract that responded to a gluten-free diet. What Is the Histologic Spectrum of This Disease in Patients With Celiac Disease? Celiac disease itself is associated with histologic evidence of increased intraepithelial lymphocytes (often defined as more than 40 lymphocytes per 100 enterocytes), villous atrophy, and crypt hyperplasia. Refractory celiac disease (RCD) is clinically defined as persistent villous atrophy with crypt hyperplasia and increased intraepithelial lymphocytes despite a strict gluten-free diet for more than 12 months or when severe persistent symptoms necessitate clinical intervention independent of the duration of a gluten-free diet.11 Two types of RCD have recently been distinguished.11 Both types are morphologically characterized by persistent features of celiac disease (ie, increased intraepithelial lymphocytes, villous atrophy, and crypt hyperplasia), with RCD type I showing no atypia in intraepithelial lymphocytes, normal surface T-cell receptor, CD3 and CD8 expression by intraepithelial T lymphocytes, and a polyclonal pattern shown by Tcell receptor gene rearrangement studies. Patients may benefit A B C D Image 3 (Case 93) CD56 enteropathy-type T-cell lymphoma. This jejunal resection specimen showed multiple ulcers (A, H&E, 20) with diffuse pan-mural infiltration by atypical pleomorphic medium to large neoplastic cells (B, H&E, 400). In the adjacent jejunal epithelium, infiltration by atypical intraepithelial lymphocytes was observed (C, H&E, 400). The neoplastic cells expressed CD3 (D, left, 400) and granzyme B (D, right, 400). 704 Am J Clin Pathol 2007;127:701-706 Downloaded 704 from https://academic.oup.com/ajcp/article-abstract/127/5/701/1759953

AJCP / SHP/EAHP WORKSHOP from reassessment of their gluten-free diet (ingestion of occult glutens?). RCD type II, by contrast, although usually not showing atypia in intraepithelial T lymphocytes, is characterized by a loss of surface T-cell receptor, CD3, or CD8 expression and commonly shows monoclonal T-cell receptor gene rearrangement. Furthermore, as shown by Verkarre et al, 12 intraepithelial lymphocytes in these cases often show clonal cytogenetic alterations. RCD type II thus corresponds to cryptic ETL and may represent the missing link between celiac disease and ETL. 13 In established ETL, it is often difficult to obtain precise clinical information about a history of celiac disease because more than 40% of the patients die soon after disease manifestation, usually of intestinal perforation or septicemia, with no further clinical follow-up and workup. In the remaining patients with ETL, a well-established clinical malabsorption syndrome that is present before the diagnosis of ETL may already be a manifestation of lymphoma, and, in this scenario, unequivocal establishment of preexisting celiac disease is also difficult. Is There Any Value in the Histologic Subclassification of ETL? Recent morphologic, immunophenotypic, and genetic data suggest that ETL can be divided into 2 groups. 9,10,15 Approximately 80% of ETLs are characterized by pleomorphic to anaplastic tumor cells, a high rate of associated celiac disease (up to 70% of cases), and the presence of enteropathytype mucosal changes adjacent to the invasive tumor (85% of cases). 9 Immunohistochemically, these neoplasms commonly express CD3 and TIA1, are usually negative for CD56, as well as for CD4 and CD5, and express CD8 in approximately 20% of cases (Image 3). In contrast, approximately 20% of ETLs are characterized by mostly monomorphic, small to medium-sized tumor cells, are rarely preceded by celiac disease, and, less frequently, show histologic evidence of enteropathy-type mucosal changes (50%). Immunohistochemically, these neoplasms frequently express CD56 (>90%) and CD8 (80%). Furthermore, these neoplasms commonly express cytotoxic markers and are negative for CD4 and CD5 (Image 2). Does the Anatomic Site of ETL Have Any Role in Diagnosis (eg, Stomach vs Intestine)? There is no evidence to suggest that T-cell lymphomas arising in the stomach or colon represent a different tumor type from ETL arising in the jejunum or ileum. Thus, ETL may also be the correct designation for T-cell lymphomas arising in any of the aforementioned gastrointestinal tract locations. There are 2 arguments to support this notion: (1) T-cell lymphomas arising in the stomach or colon show a pattern of genetic alterations similar to classic ETL arising in the jejunum or ileum. 10 (2) Verkarre et al 14 showed in patients with RCD that abnormal clonal T-cell populations with aberrant immunophenotypes can be detected in the stomach and colon. These findings suggest that RCD, considered a precursor of ETL, is a disseminated gastrointestinal tract disease and can give rise to ETL at any of these locations. Is FISH Analysis for Abnormalities of Chromosome 9 Essential for the Diagnosis and Workup of ETL? Gains of chromosome 9q33-q34 are the hallmark genetic alteration in ETL, occurring in up to 70% of cases. 10,15 Furthermore, gains of 9q33-q34 are reported only in rare cases of other T-cell lymphoma entities characterized genetically to date. 16-19 For the cases of ETL submitted to the Workshop, 5 could be tested for 9q gains by fluorescence in situ hybridization (FISH) Table 1. In 4 of these cases, gains of 9q were shown using a probe for chromosome 9q34 (BAC clone LP11/229P13); only 1 case was negative. It is interesting that among the positive cases was a T-cell lymphoma that initially was submitted and classified by the expert panel as primary gastric PTCL, not otherwise specified. However, in view of the presence of the chromosome 9q gain, it was ultimately reclassified as ETL manifesting in the stomach. Thus, FISH for chromosome 9q may be a promising molecular tool for Table 1 Results of FISH Studies for Gains of Chromosome 9q in Intestinal T-Cell Lymphoma Cases Submitted for the SHP/EAHP Workshop * Case No. Panel Diagnosis Gain of Chromosome 9q 37 ETL Positive (3-4 [85]) 131 ETL Positive (3 [40]) 140 ETL (?) Positive (3-5 [40]) 228 ETL Positive (3-5 [60]) 62 ETL Negative 103 PTCL Negative 142 PTCL Negative 28 Suggestive of NK lymphoma Negative ETL, enteropathy-type T-cell lymphoma; FISH, fluorescence in situ hybridization; PTCL, peripheral T-cell lymphoma; SHP/EAHP, Society for Hematopathology/European Association for Haematopathology. * In 8 submitted cases of T-cell lymphoma involving the gastrointestinal tract, FISH was performed using a probe for chromosome 9q34 (BAC clone LP11/229P13). In 4 of 5 cases classified as ETL, gains of 9q were observed. In contrast, in 3 cases of T-cell lymphoma not classified as ETL by the panel, no gain of 9q was observed. Case 140, a T-cell lymphoma manifesting in the stomach, was reclassified as ETL by the panel when FISH results became available. Gains of 9q are given as (number [percentage]). Downloaded from https://academic.oup.com/ajcp/article-abstract/127/5/701/1759953 Am J Clin Pathol 2007;127:701-706 705 705 705

Zettl et al / ENTEROPATHY-TYPE T-CELL LYMPHOMA confirming the diagnosis of ETL. However, the sensitivity and specificity of FISH for 9q abnormalities have not yet been tested in a large series of T-cell lymphomas. Furthermore, it is not known whether 9q gains identify histologically overt ETL or are already present at the stage of so-called cryptic ETL. Can Other T-Cell Lymphoma Types Primarily Involve the Gastrointestinal Tract? ETL is by far the most frequent T-cell lymphoma arising in the intestine. Although rare, there are other types of T-cell lymphoma defined by the World Health Organization classification that can manifest in the intestine. In the Workshop, 3 cases of T-cell lymphoma with initial disease manifestation in the gastrointestinal tract were presented, among them a γδ T- cell lymphoma (case 103), a composite diffuse large B-cell lymphoma and peripheral T-cell lymphoma, not otherwise specified (case 121), and a case of CD15+CD30+ PTCL, not otherwise specified (case 142). Of note, FISH analyses in 2 of the cases tested were negative for 9q gains (Table 1). Bearing in mind its enormous histomorphologic variability, ETL remains the most likely diagnosis when a T-cell lymphoma initially manifests with gastrointestinal tract involvement, but other types of T-cell lymphoma should also be considered. From the 1 Institute of Pathology, University of Würzburg, Würzburg, Germany; and 2 British Columbia Cancer Center, Vancouver, Canada. Address reprint requests to Dr Mueller-Hermelink: Institute of Pathology, University of Würzburg, Würzburg, Germany. Acknowledgments: The following were contributors or cocontributors of cases to this session: A. Abou-Elella, S. Al- Quran, H.W. Bernd, E. Bishop, A. De Mascarel, F. Fend, K. Hebeda, E.S. Jaffe, K. Elenitoba-Johnson, J. Ferry, K. Gaal, R. Gascoyne, K. Kernek, S. Kroft, S. Rezk, A. Sands, R. Simental- Pizarro, R. Valdez, F. Vega, V. Willoughby, and A. Zettl. References 1. Isaacson P, Wright D, Ralfkiaer E, et al. Enteropathy-type T-cell lymphoma. In: Jaffe ES, Harris NL, Stein H, et al, eds. Pathology and Genetics of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: IARC Press; 2001:208-209. World Health Organization Classification of Tumours. 2. Isaacson PG, Wright DH. Malignant histiocytosis of the intestine: its relationship to malabsorption and ulcerative jejunitis. Hum Pathol. 1978;9:661-677. 3. Isaacson PG, O Connor NT, Spencer J, et al. Malignant histiocytosis of the intestine: a T-cell lymphoma. Lancet. 1985;18:688-691. 4. 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Most CD56+ intestinal lymphomas are CD8+CD5 T-cell lymphomas of monomorphic small to medium size histology. Am J Pathol. 1998;153:1483-1490. 10. Zettl A, Ott G, Makulik A, et al. Chromosomal gains at 9q characterize enteropathy-type T-cell lymphoma. Am J Pathol. 2002;161:1635-1645. 11. Daum S, Cellier C, Mulder CJ. Refractory celiac disease. Best Pract Res Clin Gastroenterol. 2005;19:413-424. 12. Verkarre V, Romana SP, Cellier C, et al. Recurrent partial trisomy 1q22-q44 in clonal intraepithelial lymphocytes in refractory celiac sprue. Gastroenterology. 2003;125:40-46. 13. Cellier C, Delabesse E, Helmer C, et al. Refractory sprue, celiac disease and enteropathy-associated T-cell lymphoma. Lancet. 2000;356:203-208. 14. Verkarre V, Asnafi V, Lecomte T, et al. Refractory celiac disease is a diffuse gastrointestinal disease. Gut. 2003;52:205-211. 15. deleeuw R, Zettle A, Klinker E, et al. Whole genome analysis and HLA genotyping of enteropathy-type T-cell lymphoma reveals two distinct lymphoma subtypes. Gastroenterology. In press. 16. Zettl A, Rüdiger T, Konrad MA, et al. Genomic profiling of peripheral T-cell lymphoma, unspecified and anaplastic large T-cell lymphoma delineates novel recurrent chromosomal alterations. Am J Pathol. 2004;164:1837-1848. 17. Tsukasaki K, Krebs J, Nagai K, et al. Comparative genomic hybridization analysis in adult T-cell leukemia/lymphoma: correlation with clinical course. Blood. 2000;97:3875-3881. 18. Soulier J, Pierron G, Vecchione D, et al. A complex pattern of recurrent chromosomal losses and gains in T-cell prolymphocytic leukemia. Genes Chromosomes Cancer. 2000;31:248-254. 19. Siu LP, Wong KF, Chan JKC, et al. Comparative genomic hybridization analysis of natural killer cell lymphoma/leukemia. 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