FOLLICULAR LYMPHOMA GRADE 1-2/3

Case provided by Jila Khorsand, MD

Case History

The patient is a 60 year old female presenting a history of intermittent partial obstruction. Her current episode of partial obstruction seems to be her longest and most protracted. A CT scan of the abdomen showed an extremely abnormal appearing loop in the lower abdomen, which was dilated in fusiform fashion and filled with soft tissue material and an exploratory laparatomy was performed. Approximately 2 ft proximal to the terminal ileum, an abnormal patch of small bowel was identified. Some enlarged lymph nodes within the mesentery leading away from the abnormal segment were also noted. The abnormal segment and attached mesentery was resected.

Microscopic Findings

H&E slides showed a dense lymphoid infiltrate with a follicular pattern. Neoplastic follicles were predominantly composed of centrocytes; however, occasional centroblats were also identified. The lymphoid infiltrate involved the mucosa, sub mucosa, muscularis propria and subserosal adipose tissue. Immunoperoxidase stains showed the neoplastic cells to be CD20, BCL2, and BCL6 positive.  Ki 67 stain highlighted 20-30% of the neoplastic nuclei within the follicles. Scattered CD10 positivity was also noted. CD 21 showed the expanded follicular dendritic cell net work.

Diagnosis

FOLLICULAR LYMPHOMA GRADE 1-2/3

Discussion

Follicular lymphoma (FL) accounts for about 20% of all lymphomas. The median age of affected adults occurs in the sixth decade. FL is predominantly a nodal disease; however it may occur in extra nodal sites such as skin, GI tract, soft tissue and breast. In the GI tract the most common lymphoma is Low Grade Mucosa Associated Lymphoid Tissue (MALT) lymphoma. FL of the GI tract is rare and accounts for 1-3% of GI lymphomas. The neoplastic lymphoid cells express CD19, CD20, CD22, and CD79a and are positive for BCL2, BCL6 and CD10. FL is characterized by translocation (14; 18) (q32; q21) and BCL2 gene rearrangement. The prognosis is related to stage at the time of diagnosis and the histologic grade. Cases of Grades 1 and 2 generally behave as indolent lymphomas and are usually incurable, whereas grade 3 FL has a more aggressive course thereby justifying chemotherapy regimens containing doxorubicin and /or rituximab.  

References

1. WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues, edited by S.H. Swerdlow, E. Campo, N.L. Harris, E.S. Jaffe, et al., IARC, 2008.

2. Primary Follicular Lymphoma of the Small Intestine; Richard J. Bende, Laura A. Smit, Janneke G. Bossenbroek ,et al. American Journal of  Pathology. Jan 2003;162(1): 105-113

 

H&E Stain; Low Power Magnification: full thickness involvement of small bowel by follicular lymphoma
H&E Stain; Medium Power Magnification: follicular lymphoma of small bowel
H&E Stain; Medium Power Magnification: small bowel with dense nodular lymphoid infiltrate
H&E Stain; Medium Power Magnification: neoplastic lymphoid cells infiltrate through muscularis propria
H&E Stain; High Power Magnification: neoplastic lymphoid cells infiltrate through muscularis propria
H&E Stain; Medium Power Magnification: extensive involvement of serosal surfaces
H&E Stain; High Power Magnification: neoplastic centrocytes and rare centroblasts
H&E Stain; Medium Power Magnification: focal interstitial fibrosis
IPOX Stain; Low Power Magnification: small bowel mass, CD20
IPOX Stain; Medium Power Magnification: small bowel mass, CD20
IPOX Stain; High Power Magnification: small bowel mass, CD20
IPOX Stain; Low Power Magnification: small bowel mass, BCL2
IPOX Stain; Medium Power Magnification: small bowel mass, CD23
IPOX Stain; Medium Power Magnification: small bowel mass, CD10, occasional cells with weak staining pattern
IPOX Stain; Low Power Magnification: small bowel mass, Ki-67
IPOX Stain; High Power Magnification: small bowel mass, Ki-67