Low-grade Pancreatic Intraepithelial Neoplasia Mimicking Branch-Duct IPMN in a Patient with Long-standing Systemic Lupus Erythematosus: A Case Report

Technical Summary: Low-grade Pancreatic Intraepithelial Neoplasia Mimicking Branch-Duct IPMN in a Patient with Long-standing Systemic Lupus Erythematosus

Problem Statement
The clinical management of pancreatic cystic lesions is complicated by the radiological overlap between low-grade pancreatic intraepithelial neoplasia (PanIN-LG) and branch-duct intraductal papillary mucinous neoplasm (BD-IPMN). While BD-IPMN carries a known malignant potential requiring surgical consideration, PanIN-LG is typically a microscopic precursor lesion that is rarely diagnosed preoperatively. This diagnostic ambiguity is further exacerbated in patients with Systemic Lupus Erythematosus (SLE) on chronic glucocorticoid therapy. In this population, the risks of perioperative complications—specifically impaired wound healing, infection susceptibility, and immune dysregulation—are significantly elevated. The paper addresses the lack of reported cases where PanIN-LG radiologically mimics BD-IPMN in an SLE patient, leading to surgical intervention followed by a cascade of severe postoperative complications.

Methodology
This study is a single-case report adhering to the CARE reporting guidelines. It details the clinical course of a 56-year-old female with a 23-year history of SLE, managed with long-term methylprednisolone and hydroxychloroquine.

• Diagnostic Approach: The patient presented with incidental findings of a pancreatic neck cystic lesion during a rheumatology admission. Diagnosis relied on abdominal MRI, Magnetic Resonance Cholangiopancreatography (MRCP), and serum tumor markers (CA19-9 and CA125).
• Intervention: Based on Multidisciplinary Team (MDT) discussion, the patient underwent a laparoscopic central pancreatectomy with pancreaticojejunostomy, intended to preserve pancreatic function while removing the suspected BD-IPMN.
• Postoperative Management: The patient experienced a complex postoperative course involving clinically relevant postoperative pancreatic fistula (POPF), massive hemorrhage, and sepsis. Management included emergency reoperation (distal pancreatectomy and splenectomy), therapeutic plasma exchange, continuous blood purification, and immunomodulatory therapy to address secondary Thrombotic Thrombocytopenic Purpura (TTP) and SLE reactivation.
• Analysis: The study retrospectively analyzes the diagnostic discrepancy between preoperative imaging and final histopathology, as well as the pathophysiological mechanisms linking the surgical trauma, infection, and autoimmune flare.

Key Results

• Diagnostic Discrepancy: Preoperative imaging (MRI/MRCP) and elevated CA19-9 (147.59 U/mL) strongly suggested BD-IPMN. However, final histopathology revealed only PanIN-LG with no high-grade dysplasia or invasive carcinoma, confirming that PanIN-LG can mimic the radiological features of BD-IPMN.
• Surgical Complications: The patient developed a Grade C POPF, leading to intra-abdominal abscesses and massive hemorrhage on postoperative day 17, necessitating emergency reoperation.
• Systemic Complications: The postoperative trajectory was complicated by a "vicious cycle" of infection, SLE reactivation, and secondary TTP. The patient exhibited severe thrombocytopenia, microangiopathic hemolytic features, and acute renal impairment.
• Outcome: Through coordinated multidisciplinary management involving rheumatology, critical care, and surgery, the patient eventually stabilized, with recovery of platelet counts and renal function, though she required prolonged care for wound dehiscence and gastric fistula.

Key Contributions
The paper provides two primary clinical insights:

1. Diagnostic Limitations: It highlights that conventional cross-sectional imaging has inherent limitations in differentiating PanIN-LG from BD-IPMN. The authors suggest that in ambiguous cases, particularly where the diagnosis is uncertain, Endoscopic Ultrasound with Fine-Needle Aspiration (EUS-FNA) and cyst fluid molecular profiling should be considered to refine preoperative diagnosis.
2. Risk Stratification in SLE: It underscores that in SLE patients on chronic immunosuppression, the perioperative risks of pancreatic surgery may substantially outweigh the oncological benefits for low-risk lesions. The case demonstrates how surgical stress and infection can trigger a self-perpetuating cycle of "infection–immune activation–tissue injury," leading to catastrophic outcomes like TTP and multi-organ failure.

Significance and Claims
The authors claim this report is the first to document the co-occurrence of PanIN-LG mimicking BD-IPMN in an SLE patient resulting in such severe postoperative complications. The significance of the work lies in its call for a more individualized, risk-stratified approach to surgical decision-making in immunocompromised patients. The paper argues that for low-risk lesions in SLE patients, a conservative diagnostic pathway (incorporating EUS-FNA and surveillance) may be preferable to immediate resection. Furthermore, it emphasizes the necessity of a unified therapeutic principle that simultaneously manages infection control and immunomodulation to prevent the reactivation of autoimmune disease and subsequent tissue injury. The authors modestly note that as a single case report, the findings require validation through future multicenter registries to refine management strategies for this specific patient population.