Immunoblastic lymphadenopathy-like T-cell lymphoma complicated by multiple gastrointestinal involvement

How I Diagnose Angioimmunoblastic T-Cell Lymphoma

OBJECTIVES

Angioimmunoblastic T-cell lymphoma (AITL) is a subtype of peripheral T-cell lymphoma derived from T-follicular helper cells. For pathologists, diagnosing AITL may be challenging due to its wide clinical and histopathologic spectrum, which can mimic a variety of reactive and neoplastic processes.

METHODS

We summarize and discuss the clinicopathologic features of AITL, emphasizing diagnostic tools available to the practicing pathologist. Common diagnostic dilemmas are discussed.

RESULTS

AITL exhibits various histologic patterns and is often associated with a prominent microenvironment that can obscure the neoplastic cells. Atypical B-cell proliferations, which can take a number of forms, are common in AITL, and clonal B-cell expansion can be seen. The atypical B cells can closely resemble Hodgkin/Reed-Sternberg cells, leading to misdiagnosis as classic Hodgkin lymphoma. Molecular studies have revealed recurrent genetic alterations, which can aid in differential diagnosis, particularly in problematic cases.

CONCLUSIONS

Given the complex diagnostic challenges in AITL, an integrated approach, incorporating clinical, morphologic, immunophenotypic, and molecular findings, is helpful to reach an accurate diagnosis.

Primary colorectal lymphoma: computed tomography and double-contrast barium enema examination findings with histopathological correlation in 19 patients

Background

Primary colorectal lymphoma (PCL) is a rare disorder, the accurate imaging diagnosis of which remains a clinical challenge. This study aimed to characterize the imaging features of PCL by double-contrast barium enema (DCBE) examination and computed tomography (CT) and correlate them with histopathological findings.

Methods

DCBE (n=6) and CT (n=19) findings for 19 pathologically proven PCLs were evaluated and compared with histopathological findings in this retrospective analysis.

Results

Non-Hodgkin lymphoma was present in all patients, and the most common histological type was diffuse large B-cell lymphoma (63.2%, 12/19). The most common site was the ileocecum (84.2%, 16/19). CT revealed circumferential infiltrative lesions (68.4%, 13/19), polypoid masses (26.3%, 5/19) and ulcerative lesions (5.3%, 1/19). Most (94.7%, 18/19) lesions appeared as moderate enhancements. Fourteen (73.7%, 14/19) patients had serous membrane infiltration presenting as a poorly defined serous membrane and focal opacities in the pericolonic fat. Regional lymph node involvement was observed in twelve (63.2%, 12/19) patients who presented with aggregated nodules or masses. Frequent findings of the DCBE exam included a filling defect and niche with slight mucosal destruction, mild luminal narrowing and preserved peristalsis. The imaging appearance reflected the gross pathological findings well, although the preoperative diagnostic accuracy was low.

Conclusions

The imaging features of PCL have a relatively characteristic appearance but are still, at times, hardly differentiated from carcinoma. Familiarity with the radiological features of PCL on DCBE and CT can help ensure a correct diagnosis.

Indolent T- and NK-cell lymphoproliferative disorders of the gastrointestinal tract: a review and update

Primary gastrointestinal (GI) T- and NK-cell lymphomas are usually aggressive neoplasms associated with high morbidity and mortality. Over the past two decades, however, cases of primary GI lymphoproliferative disorders (LPDs) or lymphomas of T- or NK-cell derivation with indolent behavior have been reported. These LPDs are rare and they can be challenging to diagnose as they share clinical and pathological features with both, inflammatory disorders and aggressive T- and NK-cell lymphomas. Primary, indolent clonal T-cell proliferations of the GI tract, which can be CD4+, CD8+ or CD4- CD8-, have been included as a provisional entity in the newly revised World Health Organization (WHO) classification of lymphoid neoplasms and designated 'indolent T-cell LPD of the GI tract'. It is currently unclear whether the indolent NK-cell LPDs represent reactive or neoplastic proliferations. In this review, we describe the clinical, morphologic, immunophenotypic and genetic features of indolent GI T- and NK-cell LPDs and provide guidance in differentiating them from other inflammatory and neoplastic diseases. We believe that greater awareness of these LPDs amongst physicians and the research community will lead to timely and accurate diagnoses, stimulate investigations into the pathogenetic mechanisms underlying different entities thereby enhancing our understanding of disease biology and enable the development of effective therapeutic regimens. Copyright © 2016 John Wiley & Sons, Ltd.

Indolent small intestinal CD4+ T-cell lymphoma is a distinct entity with unique biologic and clinical features

Enteropathy-associated T-cell lymphomas (EATL) are rare and generally aggressive types of peripheral T-cell lymphomas. Rare cases of primary, small intestinal CD4+ T-cell lymphomas with indolent behavior have been described, but are not well characterized. We describe morphologic, phenotypic, genomic and clinical features of 3 cases of indolent primary small intestinal CD4+ T-cell lymphomas. All patients presented with diarrhea and weight loss and were diagnosed with celiac disease refractory to a gluten free diet at referring institutions. Small intestinal biopsies showed crypt hyperplasia, villous atrophy and a dense lamina propria infiltrate of small-sized CD4+ T-cells often with CD7 downregulation or loss. Gastric and colonic involvement was also detected (n = 2 each). Persistent, clonal TCRβ gene rearrangement products were detected at multiple sites. SNP array analysis showed relative genomic stability, early in disease course, and non-recurrent genetic abnormalities, but complex changes were seen at disease transformation (n = 1). Two patients are alive with persistent disease (4.6 and 2.5 years post-diagnosis), despite immunomodulatory therapy; one died due to bowel perforation related to large cell transformation 11 years post-diagnosis. Unique pathobiologic features warrant designation of indolent small intestinal CD4+ T-cell lymphoma as a distinct entity, greater awareness of which would avoid misdiagnosis as EATL or an inflammatory disorder, especially celiac disease.

Two cases of adult T-cell leukemia/lymphoma involving the terminal ileum

We describe two cases of adult T-cell leukemia/lymphoma (ATLL) with terminal ileal involvement. The first case, a 71-year-old man with lymphoma subtype of ATLL, had a polypoid lesion in the terminal ileum, in addition to a duodenal mass. The second case, a 58-year-old woman with lymphoma subtype of ATLL, had an irregular ulcerative lesion in the terminal ileum and multiple ulcers throughout the stomach. Biopsies from these lesions revealed mucosal invasion of ATLL cells in each case. In the second case, combination chemotherapy was transiently effective, resulting in the disappearance of gastric and terminal ileal lesions. Prospective and careful examination of additional cases should further characterize the clinicopathological features of terminal ileal involvement in ATLL.

CT findings in peripheral T-cell lymphoma involving the gastrointestinal tract

PURPOSE

To evaluate whether computed tomography (CT) accurately depicted gastrointestinal tract involvement in peripheral T-cell lymphoma (PTCL).

MATERIALS AND METHODS

CT scans were retrospectively reviewed in 14 patients with pathologically proved PTCLs of the gastrointestinal tract for the following considerations: sites, patterns of involvement (ie, morphologic features, bowel wall thickness or mass size, and contrast enhancement pattern), and ancillary findings at other sites (ie, lymphadenopathy, bowel perforation, and involvement of other organs).

RESULTS

PTCL involved the stomach in three patients, the small intestine in eight, both the stomach and the small intestine in one, and the sigmoid colon in two; multifocal involvement was seen in three (21%) patients. CT failed to demonstrate the bowel lesions in three of 14 patients. At CT, 11 patients had gastric or bowel wall thickening (n = 10) and a polypoid mass (n = 1). In 10 patients, the gastric or bowel wall thickening was mild (<1 cm) in six, moderate (1-2 cm) in three, and severe (>2 cm) in one. Lymphadenopathy was noted in nine (64%) patients, with the nonbulky type in eight and the bulky type in one. Bowel perforation occurred in four (29%) patients. Other organs were involved in eight (57%) patients.

CONCLUSION

CT can depict PTCL involving the gastrointestinal tract if it is not confined to the mucosa. There is a tendency toward preferential jejunal or duodenal involvement, as well as bowel perforation.

Peripheral T-cell lymphoma of the colon: double-contrast barium enema examination findings in six patients

PURPOSE

To evaluate radiologic findings of peripheral T-cell lymphoma (PTCL) of the colon at double-contrast barium enema examination.

MATERIALS AND METHODS

Double-contrast barium enema findings in six patients with pathologically proved PTCL of the colon were retrospectively evaluated and compared with colonoscopic and histopathologic findings.

RESULTS

There was a diffuse involvement of almost all segments of the colon in four patients and a focal segmental involvement in two. Frequent findings at double-contrast barium enema examination included geographic ulcerations (n = 6), aphthous ulcerations (n = 4), pseudopolyps (n = 4), circumferential luminal narrowing (n = 4), and ileocecal deformity (n = 4).

CONCLUSION

PTCL of the colon manifested as either a diffuse or a focal segmental lesion and showed extensive mucosal ulceration at double-contrast barium enema examination. These findings are similar to those of inflammatory bowel disease and are different from those of colorectal lymphoma with the B-cell phenotype.