What is the best course of action for a 30-year-old male (YOM) with a history of high-grade B cell lymphoma, status post treatment, presenting to the emergency department (ED) with right lower quadrant (RLQ) abdominal pain?

Immediate CT Abdomen/Pelvis with IV Contrast is Essential

This patient requires urgent CT abdomen and pelvis with IV contrast to evaluate for both appendicitis and lymphoma-related complications, followed by appropriate surgical or oncologic consultation based on imaging findings. 1, 2, 3

Critical Diagnostic Considerations in This Lymphoma Patient

Why This Patient is High-Risk

This 30-year-old male with recent high-grade B-cell lymphoma treatment and known bulky gastric disease presents with several concerning features that demand immediate imaging:

• Lymphoma can cause bowel perforation or obstruction even without active treatment, and this patient has documented bulky abdominal disease 4, 5
• Post-chemotherapy patients remain at risk for tumor-related complications including perforation, obstruction, or recurrence 4, 6
• RLQ pain with worsening severity requires exclusion of surgical emergencies regardless of lymphoma history 1, 3

The Imaging Decision

CT abdomen/pelvis with IV contrast is the single best initial study because it simultaneously evaluates for:

• Appendicitis (sensitivity 85.7-100%, specificity 94.8-100%) 1, 2
• Lymphoma recurrence or complications including bowel obstruction, perforation, or new masses 4, 6, 5
• Bowel obstruction from adhesions, tumor, or carcinomatosis 7, 6, 8
• Alternative diagnoses identified in 94% of non-appendiceal cases 1

The American College of Radiology specifically recommends CT with IV contrast as first-line imaging for RLQ pain in adults 1, 3. Ultrasound is inadequate in this clinical scenario and will likely require follow-up CT anyway 1.

Specific Clinical Assessment Points Before Imaging

While arranging urgent CT, assess for:

• Peritoneal signs (guarding, rebound, rigidity) suggesting perforation or acute surgical abdomen 7, 4
• Fever and degree of leukocytosis which increase likelihood of appendicitis or infection 1, 2
• Bowel sounds and abdominal distension to evaluate for obstruction 7
• Previous surgical history (85% sensitivity for adhesive obstruction if prior surgery) 7

Post-CT Management Algorithm

If CT Shows Appendicitis

• Immediate surgical consultation for appendectomy 1, 2
• Coordinate with oncology regarding recent chemotherapy status

If CT Shows Lymphoma Recurrence or Complications

• Bowel perforation: Emergency surgical consultation for laparotomy 4
• Bowel obstruction: Determine if from lymphoma mass, adhesions, or carcinomatosis; surgical vs. oncologic management depends on etiology 7, 6, 8
• New or enlarging masses: Urgent oncology consultation for biopsy and restaging 7, 5

If CT Shows Bowel Obstruction Without Clear Lymphoma

• Small bowel obstruction is most commonly from adhesions (55-75%), but in lymphoma patients consider tumor recurrence, mesenteric involvement, or carcinomatosis 7, 6, 8
• Surgical consultation for management decision (conservative vs. operative) 7
• Consider biopsy if mass lesion identified, as follicular or other lymphomas can present with obstruction 8

If CT is Negative

• Do not assume functional pain without excluding other pathology 1
• Consider gastric lymphoma-related symptoms (dyspepsia, gastritis) and arrange outpatient gastroenterology follow-up 7, 5
• Ensure appropriate oncologic surveillance is maintained 7

Critical Pitfalls to Avoid

• Do not delay imaging for prolonged observation in a patient with cancer history and worsening pain, as CT changes management in the majority of cases 1, 2
• Do not assume pain is lymphoma-related without excluding surgical emergencies, as appendicitis and other acute conditions occur at the same rate regardless of cancer history 1, 3
• Do not start empiric antibiotics before obtaining blood cultures if infection is suspected, as this may obscure diagnosis 2
• Do not order ultrasound as the sole initial study in this adult male, as it has inadequate sensitivity and specificity for the differential diagnosis 1
• Remember that lymphoma can perforate spontaneously before or after treatment, presenting as acute surgical abdomen 4, 5

Laboratory Work-Up Concurrent with Imaging

Obtain immediately:

• Complete blood count to assess leukocytosis and baseline hematologic status 2, 3
• Lactate dehydrogenase as marker of lymphoma activity 7
• Blood cultures if febrile before any antibiotics 2
• Basic metabolic panel to assess for tumor lysis or metabolic derangements 7