Contributed by by J. Manuel Zarandona, MD and Fiona E. Craig, MD
Published on line in October 2005
A woman in her 80s presented after two weeks of intermittent generalized abdominal pain. Symptoms worsened over a 48-hour period with no bowel movements, severe pain, and nausea and vomiting. In the emergency department, physical examination was significant for abdominal distention and tenderness.
An abdominal CT scan demonstrated a high-grade bowel obstruction secondary to a cecal mass. The patient underwent an emergent ileocolic resection. Intraoperatively, there was an intussusception at the ileocecal valve.
The specimen is a 24 cm segment of terminal ileum leading into a 25 cm segment of colon (Fig 1). A 5.5 x 4 x 1.7 cm rubbery tan polypoid mass is present at the ileocecal junction. On cut section, the mass appears to involve the submucosa, with displacement of the overlying mucosa. The remaining the terminal ileum and colon are uninvolved and are grossly normal.
Sections of the ileocecal mass demonstrate an abnormal lymphoid infiltrate expanding the submucosa and extending to the muscularis propria (click Here for a whole slide image of the specimen). The infiltrate focally extends through the muscularis mucosa into the lamina propria (Fig 2). The lymphoid infiltrate consists mostly of sheets but contained nodular areas (Fig 3). The lymphocytes are small and have nuclei with irregular, somewhat angulated contours and condensed chromatin (Fig 4). There are also a few scattered lymphocytes with larger nuclei and nucleoli (Fig. 5). Many prominent mitotic figures are present (Fig 6). Finally, many thick-walled, partially hyalinized blood vessels are identified (Fig 7).
FLOW CYTOMETRIC IMMUNOPHENOTYPIC STUDIES:
Flow cytometric studies demonstrate a kappa light chain restricted B-cell population (Fig 8). Additionally, these B-lymphocytes are CD19 positive, CD5 positive, CD23 negative, FMC-7 negative, and CD20 positive (moderate intensity). A heterogeneous T-lymphocyte population is also present.
Numerous lymphocytes are positive for cyclin-D1.