Hematology-Oncology Management Recommendation

Hold further mosunetuzumab/polatuzumab dosing until the small bowel obstruction and pelvic abscess are definitively resolved, prioritize aggressive supportive care including TPN for severe malnutrition, continue NGT decompression and IR drain management, and reassess for CAR T-cell therapy referral once medically stabilized given her early lymphoma response but high-risk relapsed disease.

Immediate Management Priorities

Lymphoma-Directed Therapy: Temporary Hold

Your decision to hold today's mosunetuzumab dose is absolutely correct. The patient has:

Mechanical SBO with severe gastric/small bowel distention (up to 4.3 cm)
Pelvic abscess requiring drainage
Severe protein-calorie malnutrition (albumin 2.4)
Active infection (purulent pelvic collection, CRP 30.7)

Administering further immunotherapy in this setting risks:

Worsening enterocolitis (immunotherapy-associated)
Exacerbating tumor lysis in necrotic lymph nodes with potential perforation
Overwhelming sepsis in a malnourished, immunocompromised state
Inability to manage CRS complications without corticosteroids (which would impair abscess/infection control)

The promising early response (LDH declining from >2,500 to 1,305, substantial decrease in mesenteric adenopathy) provides a therapeutic window to address life-threatening complications 1.

Nutritional Support: Critical Priority

Initiate TPN immediately as recommended by Surgical Oncology. Severe protein-calorie malnutrition (albumin 2.4, prolonged NPO status) will:

Prevent wound healing and abscess resolution
Increase infection risk
Preclude any future cellular therapy consideration
Worsen outcomes with any subsequent lymphoma treatment

Monitor electrolytes closely given persistent hyponatremia and hypokalemia. Correct deficiencies aggressively.

Infection Management

Continue Unasyn per ID recommendations. Monitor:

Culture results from pelvic abscess drainage
IR drain output (should decrease if abscess resolving)
Serial CRP and inflammatory markers
Temperature curves and WBC trends

Consider broadening coverage if cultures grow resistant organisms or if clinical deterioration occurs despite current antibiotics.

SBO Management

Continue intensive nonoperative management:

NGT decompression (monitor output volumes)
Serial abdominal exams
Strict NPO status
Consider repeat imaging in 5-7 days to assess bowel distention and lymphoma response

Surgical intervention carries prohibitive mortality risk in this setting (active lymphoma, recent immunotherapy, severe malnutrition, multiple comorbidities, age 75). The substantial decrease in mesenteric adenopathy suggests the SBO may improve as lymphoma responds.

Lymphoma Treatment Strategy: Next Steps

CAR T-Cell Therapy Consideration (Once Stabilized)

This patient should be evaluated for CAR T-cell therapy despite her age and comorbidities 1, 2, 3:

Relapsed within <1 year of R-CHOP completion (completed in prior year, relapsed now)
High-risk aggressive disease (GCB DLBCL, c-MYC 40%, Ki-67 >90%, bulky disease, LDH >2,500)
Early response to mosunetuzumab/polatuzumab demonstrates chemosensitivity
Age 75 is NOT a contraindication – recent data show feasibility even in nonagenarians with appropriate geriatric assessment 4

Key requirements before CAR T referral:

Resolution of active infection (pelvic abscess)
Nutritional rehabilitation (albumin >3.0, positive nitrogen balance on TPN)
SBO resolution or stabilization
Performance status improvement to ECOG 0-2
Adequate organ function (preserved renal function is favorable)

NCCN guidelines prioritize CAR T-cell therapy for relapsed/refractory DLBCL after ≥2 prior lines, and this patient's early response to mosunetuzumab/polatuzumab suggests she could achieve adequate disease control for bridging to CAR T 1.

Alternative if CAR T Not Feasible

If the patient cannot be stabilized for CAR T-cell therapy due to:

Persistent SBO requiring surgery
Uncontrolled infection
Declining performance status
Patient/family preference

Resume mosunetuzumab/polatuzumab once acute issues resolve:

This regimen has shown early efficacy (marked LDH decline, radiographic response)
Dose modifications may be needed given complications
Close monitoring for CRS (she had grade 1 previously, managed with dexamethasone)
Avoid rasburicase (G6PD deficiency) – continue allopurinol for TLS prophylaxis

Bispecific antibodies (glofitamab, epcoritamab) are alternatives if mosunetuzumab cannot be continued, though cross-reactivity and CRS risk remain 2, 3.

Comorbidity Management

Cardiovascular/Cerebrovascular

Continue DAPT and statin for 77% left ICA stenosis and subacute watershed infarcts
No acute vascular intervention per Vascular Surgery (appropriate given active malignancy, bleeding risk with thrombocytopenia potential)
Monitor neurologic status closely – any new deficits require urgent imaging
Cardiology follow-up for CAD management

Pulmonary/Volume Status

Discontinue IVF (already done per Nephrology) – positive fluid balance worsens pulmonary status
Continue diuresis with IV Lasix to target euvolemia
Maintain COPD regimen (Breo/Incruse, DuoNeb PRN)
Oxygen support as needed (currently 1-2L NC)
Avoid systemic steroids unless absolutely necessary (infection risk, impairs abscess healing)

Hematologic

Transfuse PRBC for Hgb <7 or symptomatic anemia (current Hgb 9.1 is acceptable)
Monitor CBC closely – expect cytopenias from mosunetuzumab/polatuzumab when resumed
G-CSF support may be needed with future therapy

Timeline for Reassessment

Week 1-2 (Current hospitalization):

Optimize nutrition with TPN
Resolve infection (pelvic abscess drainage, antibiotics)
Manage SBO nonoperatively
Continue supportive care

Week 2-3:

Repeat CT abdomen/pelvis to assess SBO resolution and lymphoma response
If improving: advance diet cautiously, wean NGT
If worsening: surgical consultation for possible intervention (though high-risk)

Week 3-4:

If medically stabilized: urgent CAR T-cell therapy referral and evaluation
If not CAR T candidate: resume mosunetuzumab/polatuzumab (cycle 1 day 8 or cycle 2 day 1 depending on timing)

Ongoing:

Defer thyroid mass evaluation until lymphoma management stabilized
Outpatient vascular surgery follow-up for carotid stenosis
Palliative care involvement for symptom management and goals-of-care discussions

Critical Pitfalls to Avoid

Do not resume immunotherapy prematurely – risk of catastrophic bowel perforation or overwhelming sepsis outweighs lymphoma progression risk given early response
Do not delay TPN – malnutrition will preclude all future treatment options
Do not dismiss CAR T candidacy based on age alone – geriatric assessment and functional status are more predictive than chronologic age 5, 6, 4
Do not use rasburicase – G6PD deficiency is absolute contraindication
Do not pursue surgical intervention for SBO unless absolute emergency – mortality risk is prohibitive

Summary Algorithm

Acute stabilization (1-3 weeks)
├─ Hold mosunetuzumab/polatuzumab
├─ Initiate TPN immediately
├─ Continue NGT decompression + IR drain management
├─ Treat infection (Unasyn, culture-directed)
└─ Optimize comorbidities (volume status, COPD, anticoagulation)
    │
    ↓
Reassess at 2-3 weeks
├─ SBO resolved? Infection cleared? Nutrition improving?
    │
    ├─ YES → CAR T-cell therapy evaluation (preferred)
    │         └─ If eligible: proceed to CAR T
    │         └─ If ineligible: resume mosunetuzumab/polatuzumab
    │
    └─ NO → Continue supportive care
              └─ Reassess weekly
              └─ Consider palliative care consultation if no improvement

The early lymphoma response provides hope, but survival depends on resolving the acute abdominal catastrophe first 1, 2.

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