Small Bowel Obstruction in a Surgically Naïve Abdomen

Diagnosis

Based on the pathologic examination of the resected tissue and immunohistochemical stains, this patient was diagnosed with malignant non-Hodgkin B-cell lymphoma, follicular type, grade 1. PET scan and bone marrow biopsy revealed no other lesions, making this a primary lymphoma of the small intestine. The resected tissue showed negative margins and negative lymph nodes, indicating the full extent of the patient’s tumor was removed. He then underwent nasogastric tube decompression and IV fluid resuscitation. Two days later, he had a large bowel movement, and his abdominal pain resolved. He was provided the treatment options of observation only, radiation therapy, or rituximab treatment. Based on the high risk of enteritis following radiation therapy, the patient elected for observation only, with a repeat scan in 6 months. He also was counseled on alcohol and tobacco cessation. At the 6-month oncology follow-up, the patient showed no evidence of disease recurrence.

Discussion

Small bowel obstruction accounts for about 350,000 hospitalizations annually in the US.¹ The incidence is equal in men and women and can present at any age.^2,3 Patients typically present nonspecifically, with intermittent, colicky abdominal pain, nausea, vomiting, and constipation.² A physical examination may reveal abdominal distention, rigidity, and hypoactive or absent bowel sounds.¹ The 2 most common etiologies of small bowel obstruction are adhesions from prior abdominal surgery (65%) and incarcerated inguinal hernias (10%).¹ However, in a patient presenting with a small bowel obstruction in a surgically naïve abdomen with no hernias, a more detailed history covering current malignancies, past hospital admissions for abdominal pains, pelvic inflammatory disease, diverticulitis, inflammatory bowel disease, and risks for parasite infection must be taken. The differential should include intraluminal causes, including small bowel malignancy, which accounts for 5% of small bowel obstructions,¹ as well as extraluminal causes, including adhesions from diverticulitis, Meckel diverticulum, Ladd bands, and undiagnosed prior appendicitis.