MCQ – 87400

Correct Answer � A Explanation

Ans.A. Malabsorption

• Immunoproliferative small intestinal disease (IPSID)was recently added to the growing list of infectious pathogen-associated human lymphomas.
• Molecular and immunohistochemical studies demonstrated an association with Campylobacter jejuni.
• IPSID is a variant of the B-cell lymphoma of mucosa-associated lymphoid tissue (MALT), which involves mainly the proximal small intestine resulting in malabsorption, diarrhea, and abdominal pain.
• Geographically, IPSID is most prevalent in the Middle East and Africa.
• IPSID lymphomas reveal excessive plasma cell differentiation and produce truncated α heavy chain proteins lacking the light chains as well as the first constant domain.
• The corresponding mRNA lacks the variable heavy chain (VH) and the constant heavy chain 1 (CH1) sequences and contains deletions as well as insertions of unknown origin.
• The encoding gene sequence reveals deletion of the V region and parts of the CH1 domain.
• Cytogenetic studies demonstrated clonal rearrangements involving predominantly the heavy and light chain genes, including t(9;14) translocation involving the PAX5 gene.
• Early-stage IPSID responds to antibiotics (30%-70% complete remission).
• Most untreated IPSID patients progress to lymphoplasmacytic and immunoblastic lymphoma invading the intestinal wall and mesenteric lymph nodes and may metastasize to a distant organ.
• IPSID lymphoma shares clinical, morphologic, and molecular features with MALT lymphoma, lymphoplasmacytic lymphoma, and plasma cell neoplasms.