Case 22- Discussion

Uploaded: 2007-09-03, Updated: 2008-01-03

• The tumor cells are negative for CD5, CD30 and Granzyme B.

FLOW CYTOMETRY ANALYSIS

An abnormal population of cells expressing bright CD45, CD2, CD7, CD11c and cytoplasmic CD3 is detected at approximately 55% of total cells. These cells are negative for surface CD3, CD5, CD25, CD26 and CD103. The CD4/CD8 ratio of the analyzed cells is 1:13.

     Total events       Bright CD45+         

     analyzed = 24701   events = 8981 (85% of   

                        total nucleated cells)    

        CD45+/CD14-           93%             

        CD19+/CD3-            <2%

        CD3+/CD19-             8%

        CD19+/CD20+           <2%

        CD19+/CD38+           <2%

        CD19+/CD10+           <2%

        CD5+/CD19+            <2%

        CD5+/CD19-             6%

        CD19+/CD23+           <2%

        CD19+/FMC+            <2%

        CD11c+                72%

        CD25+                  3%

        CD103+                11%

        CD26+                  2%

        CD2+/CD7+             91%

        CD3+/CD5+              5%

        CD4+                   7%

        CD8+                  90%

        CD16+                  9%

        CD3-/CD56+            <2%

        cCD3+                 86%

        CD7+/nTDT+            <2%

Enteropathy-Type T Cell Lymphoma

CLINICAL FEATURES

• Increasing incidence in areas with a high prevalence of celiac disease;

• Location: most commonly in the jejunum or ileum, rarely in duodenum, stomach, colon or outside the GI tract;

• Association with celiac disease, commonly presents with multiple jejunal ulcers often associated with perforation.

GROSS FINDINGS

• The tumor usually presents with multiple ulcerating raised mucosal masses, and may also present as one or more ulcers or a large exophytic mass.

MICROSCOPIC FINDINGS

• An ulcerating mucosal mass invading the intestinal wall with variable cytomorphological features;

• Tumor cells commonly infiltrate into the epithelium of individual crypts;

• Morphology of tumor cells

  • Most commonly, relatively monomorphic, medium to large; round to angulated vesicular nuclei with prominent nucleoli; moderate to abundant pale cytoplasm;

  • Occasionally, the tumor cells show marked pleomorphism with multinucleation resembling anaplastic large cell lymphoma;

  • In some cases, the tumor cells are small and monomorphic with darkly stained nuclei and minimal cytoplasm;

• Prominent reactive inflammatory cells are commonly seen, including histiocytes and eosinophils;

• Adjacent intestinal mucosa often shows enteropathy with villous atrophy, crypt hyperplasia, plasma cell infiltration and intraepithelial lymphocytosis.

SUBTYPES

DIFFERENTIAL DIAGNOSES

IMMUNOHISTOCHEMISTRY AND SPECIAL STAINS

• CD3+, CD7+, CD103+, CD8+/-;

• Positive for cytotoxic associated proteins, granzyme B, TIA1 and perforin;

• CD5-, CD4-;

• In most cases, there is a variable expression of CD30;

• In the cases with small to medium tumor cells, the tumor cells are commonly CD8+ and CD56+.

CYTOGENETIC STUDIES

• Clonal rearrangement of TCR β and γ genes;

TREATMENT AND PROGNOSIS

• Prognosis is usually poor.

REFERENCES

• Practical Diagnosis of Hematologic Disorders, Fourth Edition. By Carl R. Kjeldsberg, 2006.

• Jaffe ES, Harris NL, Stein H, Vardiman JW, editors. Pathology and genetics of tumours of haematopoietic and lymphoid tissues. World Health Organization classification of tumours. Lyon (France): IARC Press; 2001.