T-cell lymphoblastic lymphoma with colonic involvement: A case report

Abstract

BACKGROUND

The gastrointestinal (GI) tract is the most common extranodal site for non-Hodgkin lymphoma. Most GI lymphomas originate from B-cell lineages; T-cell lymphomas are notably rare. Colonic involvement by lymphoma, unlike that of the stomach and small intestine, is particularly uncommon. Patients often present with nonspecific symptoms, including pain, diarrhea, weight loss, or bleeding. At endoscopy, these tumors appear as irregular ulcers, nodular or fungating masses, or polypoid lesions; diagnosis require histopathology and immunochemical staining.

CASE SUMMARY

This report presents an apparently asymptomatic 66-year-old man who was incidentally found to have generalized lymphadenopathy on physical examination and nodular colonic lesions during colonoscopy. Cross-sectional imaging demonstrated extensive, confluent lymphadenopathy involving the retroperitoneal, bilateral iliac, inguinal, mesenteric, pelvic, and cervical nodes, concerning for a lymphoproliferative disorder. Both nodal and extranodal lesions exhibited histologically and immunologically similar T lymphoblasts, consistent with T-cell lymphoblastic lymphoma, Ann Arbor stage IV.

CONCLUSION

This case illustrates an exceptionally rare presentation of T-lymphoblastic lymphoma as colonic polypoid lesions, emphasizing the need to consider hematologic malignancies in the differential diagnosis of colorectal polyps. Early recognition, thorough histopathologic evaluation, and comprehensive staging are critical for management, given the aggressive nature and poor prognosis of these neoplasia.

Key Words: T-cell lymphoblastic lymphoma; Colon; Polyp; Colonoscopy; Gastrointestinal; Case report

Core Tip: Lymphomas involving the colon are rare, and T-cell lymphomas are even rarer. This case report describes T-cell lymphoblastic lymphoma involving the colon, presented incidentally as polypoidal lesions during routine colonoscopy, mimicking benign colorectal polyps. This case underscores the importance of thorough histopathologic and immunophenotypic evaluation of colonic polyps to enable timely diagnosis of aggressive hematologic malignancies.

INTRODUCTION

The gastrointestinal (GI) tract is the most common extra-nodal site of involvement by non-Hodgkin lymphoma (NHL). The majority of GI lymphomas arise from B-cell lineages. Diffuse large B-cell lymphoma and mucosa-associated lymphoid tissue lymphoma account for over 90% of primary GI lymphoma cases[1]. T-cell lymphomas of the GI tract are uncommon, representing only 10% to 15% of NHL and 1% to 4% of all GI cancers[1-3]. Irrespective of the lineage, the stomach and small intestines are the common sites of involvement. Primary colorectal lymphomas account for approximately 0.3% of large intestinal malignancies[2]. Patients often present with nonspecific GI symptoms, including abdominal pain, diarrhea, weight loss, or bleeding, and may develop complications such as obstruction or perforation[1,2]. Endoscopically, these tumors may appear as irregular ulcers, nodular or fungating masses, or polypoid lesions. Diagnosis is confirmed by histopathology and immunochemical staining. Therapeutic strategies include surgical intervention, systemic chemotherapy, chemoradiotherapy, and, in select cases, hematopoietic stem cell transplantation[4,5]. T-cell lymphomas are generally aggressive, with a tendency to present at an advanced stage and confer a poor prognosis, with a median survival of approximately 7-8 months[6].

Here we report a rare case of T-cell lymphoma, presenting as peripheral lymphadenopathy and polypoidal colonic lesions. Biopsies from the lesions were concordant; both demonstrated similar histology and immunophenotypes.

CASE PRESENTATION

Chief complaints

This 66-year-old man was referred to the gastroenterology clinic for a screening colonoscopy.

History of present illness

He was asymptomatic except for constipation, which he described as 2-3 bowel movements a week, formed stools with straining, which he had been having for many years. He used to get relief from his bowel complaints with a high-fiber diet and over-the-counter fiber supplements. He reported no nausea, vomiting, abdominal pain, or overt GI bleed. He denied fever, chills, night sweats, easy bruising, bleeding, malaise, loss of appetite, or weight loss. He had no genital discharge, nor has he noticed any genital ulcers.

History of past illness

The patient reported no significant past medical or surgical history.

Personal and family history

He denies any history of GI or other neoplasia among his family members.

Physical examination

Physical examination was unremarkable except for cervical and inguinal lymphadenopathy, which were not matted or tender and measured 1 cm to 2 cm, respectively. The abdominal examination was normal, with no palpable hepatosplenomegaly. Cardiopulmonary and neurological evaluation was unremarkable.

Laboratory examinations

Laboratory studies, including routine hemogram, electrolytes, and hepatic and renal function tests, were within normal limits (Table 1). Peripheral blood flow cytometry revealed 98.8% viable cells with no immunophenotypic abnormalities in B cells, T cells, NK cells, monocytes, or granulocytes, though a mild left shift was noted. T-cells constituted 6% of the total cell population, with a CD4:CD8 ratio of 0.3:1.

Table 1 Summary of the laboratory results.

Parameter	Result	Normal range
Hemoglobin	12.3	12-16 g/dL
Platelet	239	150-400 k/μL
Total leukocyte count	6.7	4.8-10.8 k/μL
Potassium	4.3	3.5-5 mEq/L
Sodium	140	135-145 mEq/L
Calcium	8.9	8.5-10.5 mg/dL
Creatinine	0.9	0.5-1.5 mg/dL
Blood urea nitrogen	22	8-26 mg/dL
Bilirubin, total	0.3	0.2-1.2 mg/dL
Bilirubin, direct	< 0.2	0.0-0.3 mg/dL
Albumin	4.1	3.4-4.8 g/dL
Aspartate transaminase	9	9-48 unit/L
Alanine aminotransferase	5	5-40 unit/L
Alkaline phosphatase	76	53-128 unit/L

Colonoscopy revealed multiple nodular lesions in the rectosigmoid colon and ascending colon, which were biopsied (Figure 1). All the colonic biopsy specimens revealed a morphologically similar cellular infiltrate composed of medium- to large-sized cells in the lamina propria. Immunostaining revealed neoplastic cells to be positive for CD34, TdT (partial), CD5, CD7, CD43, and HLADR and negative for CD3 and CD2; findings consistent with T lymphoblastic lymphoma. Ki67 showed an approximately 40% proliferative rate.

Figure 1 Colonoscopy images. A and B: Revealing nodular lesions in the sigmoid (A) and ascending (B) colon (yellow arrows).

Tumor markers: Α-fetoprotein, prostate-specific antigen, carcinoembryonic antigen, and cancer antigen 19.9 were within normal limits; so was the serum lactate dehydrogenase. In view of constipation, in the setting of extensive intra-abdominal lymphadenopathy, the patient underwent bidirectional GI endoscopic evaluation. Serology was positive for immunoglobulin G antibodies to Epstein-Barr virus (EBV) nuclear antigen (> 600 U/mL), viral capsid antigen (> 750 U/mL), and early antigen (103 U/mL); while IgM antibodies to viral capsid antigen were negative, suggesting remote EBV exposure. Quantitative polymerase chain reaction assays for EBV and cytomegalovirus nucleic acids were reported as not detected. Human immunodeficiency virus and Human T-lymphotropic virus-1 (HTLV-1) serology were negative.

Imaging examinations

Computed tomography (CT) with contrast of the chest, abdomen, and pelvis demonstrated extensive, confluent lymphadenopathy involving the retroperitoneal, bilateral iliac, inguinal, mesenteric, pelvic and cervical nodes, findings concerning for a lymphoproliferative disorder (Figure 2).

Figure 2 Contrast-enhanced computed tomography images. A-C: Demonstrating extensive, conglomerate lymphadenopathy (orange arrows) involving the retroperitoneum (A), pelvis (B), and ileoinguinal region (C).

A cervical lymph node biopsy was subsequently performed, revealing a diffuse cellular infiltrate composed of medium- to large-sized cells with fine chromatin and inconspicuous nucleoli (Figure 3). Immunostaining showed the cells to be positive for CD34, CD5, CD7, TdT (partial), and HLADR and negative for CD3, CD2, CD20, and CD10; consistent with T lymphoblastic lymphoma.

Figure 3  Cervical lymph node biopsy (hematoxylin & eosin stain; high-power) showing portions of an effaced lymph node, with diffuse lymphoid infiltrate composed of medium-sized cells with fine chromatin and inconspicuous nucleoli.

FINAL DIAGNOSIS

T-cell lymphoblastic lymphoma with colonic involvement and nodal involvement; Ann Arbor stage IV disease.

TREATMENT

The patient was referred to hematology-oncology for further evaluation and management.

OUTCOME AND FOLLOW-UP

Despite recommendations for outpatient follow-up, the patient did not return and was lost to follow-up.

DISCUSSION

Lymphomas are hematological malignancies, broadly classified as Hodgkin lymphoma or NHL based on the presence or absence of Reed-Sternberg cells, or as T-cell or B-cell lymphomas. T-cell neoplasia is further classified as T-lymphoblastic leukemia/Lymphoma, arising from T-precursor cells and mature/peripheral T-cell lymphomas. Peripheral T-cell lymphomas account for < 15% of NHL worldwide[7]. Based on the site of involvement, they include nodal and extranodal lymphomas. Cutaneous, enteral, nasal, and hepatosplenic lymphomas constitute extranodal disease. Gastrointestinal involvement could be primary disease or, more frequently, a secondary involvement[2]. T-cell lymphomas are ethnologically linked to HTLV-1, EBV, celiac disease, immunosuppression, and germ-line disorders such as ataxia telangiectasia, Nijmegen breakage syndrome, and HAVCR2 mutations[7].

Primary GI T-cell lymphoma includes enteropathy-associated T-cell lymphoma, intestinal T-cell lymphoma not otherwise specified, and extranodal NK/T-cell lymphoma[8-10]. These malignancies predominantly involve the small intestine, particularly the jejunum and ileum[11,12]. The colon is an infrequent site of involvement by GI lymphoma, accounting for about 3% of all GI lymphomas[2]. Most colorectal lymphomas are of B-cell origin. Patients with intestinal T-cell lymphoma often present with nonspecific symptoms, diarrhea, hematochezia, abdominal pain, or fever. Intestinal perforation is also a frequent complication[13-15].

Colonoscopy plays an important role in diagnosing colonic lymphoma. The endoscopic appearance of these tumors is variable; they are commonly polypoidal masses or nodularity, though mucosal ulceration may also be observed. The lesions may mimic those of inflammatory bowel diseases[4]. Endoscopic biopsies are the gold standard for diagnosing colonic lymphomas. Histopathologic examination typically reveals dense infiltrates of atypical lymphoid cells with crypt destruction and epithelial invasion. Small biopsies may pose diagnostic challenges due to inflammation, ulceration, or necrosis. Paraffin-reactive monoclonal antibodies, frozen tissue immunostaining, and receptor-gene rearrangement studies are valuable for diagnostic tools[4]. Immunological studies reveal neoplastic cells expressing B-cell or T-cell markers, depending on the cell line of origin.

Accurate staging and classification are essential for guiding diagnosis and treatment. Histopathological examination helps determine whether the lesion is confined to the mucosa or involves deeper layers. Unlike conventional endoscopic biopsy, endoscopic submucosal dissection provides a deeper, larger tissue specimen, enabling precise assessment of tumor depth, differentiation, and prognosis, while simultaneously serving as a therapeutic intervention in localized/early-stage disease[16,17]. Cross-sectional imaging modalities (CT/magnetic resonance imaging) together with positron emission tomography (PET) allow for assessing the extent of local and systemic disease[17]. The Ann Arbor system is often utilized for tumor staging. The Musshoff modification, initially described for gastric lymphomas, could also be adopted for staging. Compared with the original Ann Arbor system, the Musshoff system provides better prognostic value for overall and disease-free survival in locally advanced or regional disease, while also allowing a clear distinction between localized and disseminated disease[18].

The distinction between primary and secondary GI lymphoma is clinically relevant for management and prognosis. In 1961, Dawson et al[19] proposed diagnostic criteria to identify primary GI lymphoma. These criteria include: (1) Absent peripheral lymphadenopathy at presentation; (2) Absent mediastinal lymphadenopathy; (3) Normal total and differential white blood cell counts; (4) Predominantly bowel involvement at laparotomy with adjacent lymphadenopathy; and (5) Liver and spleen free from tumor involvement[19,20]. In 2003, Krol et al[21] examined different definitions distinguishing primary nodal from extranodal NHL; their findings revealed that in about 10% of cases, the origin could not be clearly determined. Consequently, they advocated a more flexible approach, defining primary extranodal NHL as cases in which the extranodal site is the dominant clinical feature, even when systemic spread is present.

Management follows general lymphoma treatment principles and varies according to histologic subtype, stage, and patient performance status. The role of surgery in GI lymphoma remains debated, though most reported cases have involved operative intervention. Some studies suggest that hemicolectomy may reduce the risk of complications, including spontaneous perforation, which occurs in a notable proportion of patients. Conversely, early diagnosis followed by timely chemotherapy may allow some patients to avoid surgery. In general, surgical resection is often performed in the absence of disseminated disease, providing prognostic information, preventing complications, and sometimes offering a curative option, either alone or in combination with chemotherapy[22,23]. Aggressive, rapidly proliferating lymphomas typically require systemic chemotherapy, as these malignancies often extend beyond the local site. The biological similarity between T-cell lymphoblastic leukemia and T-cell lymphoblastic lymphoma warrants similar treatment regimens for both diseases. For patients ≥ 65 years, induction: The National Comprehensive Cancer Network recommends any low-intensity or moderate-intensity regimen, or enrollment in clinical trials[23]. The low-intensity regimens include combination of vincristine, prednisone, or mercaptopurine, vincristine, methotrexate, prednisone. The moderate-intensity regimens include: (1) Mini-hyperCVD (hyperfractionated cyclophosphamide, vincristine, dexamethasone alternating with methotrexate, cytarabine); (2) Cyclophosphamide, cytarabine, dexamethasone, idarubicin, vincristine; or (3) Cyclophosphamide, dexamethasone, doxorubicin, vincristine. The induction should be followed by consolidation, often with the same low-or moderate-intensity options. The emerging approaches include venetoclax with low-intensity chemotherapy, or venetoclax with hyperCVAD/nelarbine/pegaspargase. The CD7 CAR-T cells are being investigated in relapsed or refractory cases[23].

Prognostic factors include disease stage, histological grade, and urgency of surgical intervention, with higher grade and advanced stage associated with worse outcomes. Overall, treatment should be individualized based on disease characteristics, tumor grade, and patient condition, balancing the benefits of surgery with systemic therapy to achieve optimal outcomes[24].

Our patient, an apparently asymptomatic sexagenarian, was detected to have peripheral lymphadenopathy and nodular colonic lesions on screening colonoscopy. The neoplastic cells in lymph node biopsy and colonic biopsies were histologically and immunohistochemically similar, suggesting a single neoplastic process involving both sites: T-cell lymphoblastic lymphoma. His lymphadenopathies on both sides of the diaphragm, together with extranodal involvement in the colon, classify him as Ann Arbor or Musshoff stage IV disease. The patient was referred to the hemato-oncology department for further evaluation and management. Colonic involvement of T-lymphoblastic lymphoma, mimicking colonic polyps, is exceedingly rare in published medical literature. This case adds to the sparse literature on immature/blast T-cell lymphoma involving the colon.

Limitations: The absence of bone marrow evaluation and PET imaging limited the assessment of disease extent. Furthermore, treatment details and follow-up information were unavailable, as the patient was referred to hematology-oncology services after diagnosis.

CONCLUSION

T-cell lymphoblastic lymphomas are rare but aggressive neoplasms with potential for both nodal and extranodal involvement. Although colonic involvement is uncommon, it may present as polypoidal or nodular lesions during colonoscopy. Accurate diagnosis requires integration of histopathology and immunophenotyping, while advanced imaging and endoscopic techniques support tumor staging and prognostication. Chemotherapy remains the primary treatment modality, but surgery may be warranted in selected cases to prevent complications or clarify the diagnosis. The possibility that nodular or polypoidal lesions may occasionally represent entities other than adenomas should encourage endoscopists to conduct thorough mucosal assessment and tissue sampling.