02 February 2026
: Case report 
Neoadjuvant Pressurized Intraperitoneal Aerosol Chemotherapy for Conversion to Cytoreductive Surgery in Unresectable Malignant Peritoneal Mesothelioma: A Report of 2 Cases
Challenging differential diagnosis, Unusual or unexpected effect of treatment, Rare disease
Arnaldo Urbano-Ruiz ABCDEF 1*, Bruna Latronico Palma ABCDEF 1, Ronaldo Elias Carnut Rego F 1, Daniel Bianqui Guaraldo da Silva
F 1, Bianca Fava F 1, Erlan Araujo Falcão F 1, Michelle Louise Rodrigues Barbosa da Silva F 1, Julia Rodrigues Leandro Uliano F 1
DOI: 10.12659/AJCR.950407
Am J Case Rep 2026; 27:e950407
Table 1 Summary of key clinical and procedural data for the 2 patients.
| Variable | Case 1 | Case 2 |
|---|---|---|
| Diagnostic PCI | 34 | 30 |
| Grade of small bowel involvement | Regions 9, 10, 11 and 12Larger >2.5 mm* | Regions 10, 11 and 12Seromuscular, larger >2 cm* |
| Ki-67 index | 5% | 5% |
| PIPAC cycles | 2 (5 instillations) | 1 (3 instillations) |
| Ascites (largest account) | 3900 mL | 400 mL |
| Ascites after PIPAC | absent | absent |
| Post-PIPAC PCI | 34 | 28 |
| Visual regression of implants (+, ++, +++) | +++ | ++ |
| Completeness of CRS-HIPEC | CC-0 | CC-1 |
| Length of hospital stay | 60 days | 10 days |
| Complications | None | |
| Long-term staging6 months1 year | No signs of recurrence | No signs of recurrence |
| CRS-HIPEC – cytoreduction surgery plus hyperthermic intraperitoneal chemotherapy; PCI – peritoneal cancer index; PIPAC – pressurized intraperitoneal aerosol chemotherapy. * Abdominopelvic regions for PCI according to Sugarbaker et al []. | ||