The document discusses a bone marrow biopsy showing involvement by a small B-cell neoplasm without significant plasmacytic differentiation. Immunohistochemistry staining was positive for CD20 and PAX5 and negative for other markers. The final diagnosis was follicular lymphoma with focal large cell transformation. It then provides information about colorectal lymphoma, including that it can be primary or secondary. Primary colorectal lymphoma has no involvement of lymph nodes or other organs. It discusses common types of colorectal non-Hodgkin lymphoma and stages of extranodal lymphoma. Finally, it summarizes a study of primary follicular lymphoma of the gastrointestinal tract, including presenting symptoms and findings.

1. Bone Marrow Biopsy
 Focal involvement by small B-cell neoplasm without
significant plasmacytic differentiation (CD3-, CD20+,
PAX5+, kappa IHC-, lambda IHC-, CD5-, CD10-,
BCL6-, BCL2+, cyclin D1-, IgD-, Ki67 low)
Courtesy of T Pongpruttipan, MD.

2. Review of Colonic Polyp Biospy Tissue
HE
CD20
HE HE
Courtesy of T Pongpruttipan, MD.

3. Final Pathological Diagnosis
 Involvement by small B-cell lymphoid neoplasm
with CD10+, BCL2+, BCL6- phenotype. No
evidence of large cell involvement.
 Some small and large cells showed large
aggregates with infiltrative growth pattern.
 IMP: follicular lymphoma with focus of large cell
transformation
 DDx
 DLBCL with accompanying follicular lymphoma
 Follicular lymphoma, grade 3/3 (focal) in the
background of follicular lymphoma, low grade

4. Colorectal Lymphoma
 A type of extranodal
lymphoma involving
GI tract
 Primary GI lymphoma
 Stomach 40-50%
 Small bowel 20-30%
 Colon and rectum
10-20%
 Primary GI lymphoma
 No palpable, superficial LN
 No enlarged mediastinal LN
on CXR
 Normal WBC (No and
differential count)
 Only regional LN involved
 No involvement of liver and
spleen
Dawson IM, et al. Primary malignant lymphoid tumours of the intestinal tract. Report of 37
cases with a study of factors influencing prognosis. Br J Surg 1961;49:80-9.

5. Staging of Lymphoma

6. Musshoff Modifications to Ann Arbor Staging
System for Extranodal Lymphoma
Stage
I or IE Single lymphatic organ or extranodal site
II Two or more lymphatic regions on the same site of
the diaphragm or a single extranodal organ and
lymph node involvement at the same site of
diaphragm
II1 Regional lymph node involved
II2 Distant lymph node involved
III Lymph node involved on both sides of diaphragm
IV Disseminated disease with involvement of bone
marrow, liver, etc
Musshoff K. Strahlentherapie 1977;153:218-21.
Boot H. Best Pract Res Clin Gastroenterol 2010;24(1):3-12.

7. Common Types in Colorectal NHL
 DLBCL 60%
 de novo
 Transformation from
CLL, follicular
lymphoma, MALT
 MALT 15%%
 Burkitt 15
 Recent report from
Terada T, Japan
 37 cases of GI
lymphoma
 M:F 20:17
 Median age 69 yr (46-
89)
 Types
 Gastric 25 (68%)
 Small bowel 6 (16%)
 Colon 6 (16%)
Terada T. Gastrointestinal malignant lymphoma: a pathologic study of 37 cases in a
single Japanese institution. Am J Blood Res 2012;2(3):194-200.

8. Gastrointestinal Lymphoma
 Types
 B-cell 35 (95%)
 T-cell 2 (5%)
 Gastric NHL 25
 DLBCL 11
 MALT 14
 Small intestine
 DLBCL 4
 PTCL 2
 Colon 6
 DLBCL 5
 FL 1
 Clinical diagnosis of colon
NHL at first
 GIST 1
 Colon carcinoma 4
 Colon polyp 1
 No cases of
 Hodgkin lymphoma
 Burkitt lymphoma
 Mantle cell lymphom
Terada T. Gastrointestinal malignant lymphoma: a pathologic study of 37 cases in a
single Japanese institution. Am J Blood Res 2012;2(3):194-200.

9. Primary FL of GI tract:
Massachusetts General Hospital, 1995-2010
 Excluded cases
 History of FL outside
GI tract
 Widespread
lymphoma
 Distant nodal disease
within 6 months
 Multifocal diseases
 Splenic involvement
 FL in transformation
Misdraji J, et al. Primary
follicular lymphoma of the
gastrointestinal tract. Am J
Surg Pathol 2011;35:1255-63.

10. Presenting Symptoms/ Finding
 Symptoms
 Abdominal pain and
nausea, vomiting (12),
 bowel obstruction
 Intussuspection (1)
 Incidental finding (13)
on investigation of
 Reflux symptoms or
Barrett esophagus
 Screening for
colorectal cancer
 Resection of sigmoid
carcinoma
 Macroscopic findings
 White patches or
plaques
 Mucosal nodularity or
granularity
 Nodules
 Polyp (1, 2, 3)
 Submucosal mass
 Thickening of wall or
folds
Misdraji J, et al. Primary follicular lymphoma of the gastrointestinal
tract. Am J Surg Pathol 2011;35:1255-63.