CASE STUDY

Case 1: Small Intestinal Mass

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+.

ELECTRON MICROSCOPIC FINDINGS

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.