Published in this week’s clinical literature, a rare case report details a 62-year-old man presenting with innumerable cystic hepatic metastases from a pancreatic neuroendocrine tumour. The lesions initially mimicked benign polycystic liver disease and delayed diagnosis, underscoring the critical diagnostic utility of endoscopic ultrasound and targeted tissue sampling.
Complex oncological presentations frequently challenge standard diagnostic frameworks. When malignant lesions mimic benign conditions, patient trajectories alter significantly. Investigating these atypical presentations clarifies how advanced endoscopic modalities safeguard diagnostic accuracy in hepatopancreatic pathology.
In Plain English: The Clinical Takeaway
- The Diagnostic Mimic: Cancerous liver lesions can occasionally appear as harmless fluid-filled sacs, closely resembling benign genetic conditions like polycystic liver disease or even infectious parasitic cysts such as echinococcosis.
- The Hidden Primary: Pancreatic neuroendocrine tumours account for only 1 to 2 percent of pancreatic malignancies and can remain invisible or obscure on conventional imaging while aggressively metastasizing to the liver.
- The Procedural Solution: Endoscopic ultrasound combined with fine needle aspiration is essential for obtaining definitive tissue samples when standard scans and initial biopsies remain inconclusive.
Unravelling an Atypical Presentation
Pancreatic neuroendocrine tumours (PNETs) are rare neoplasms that frequently present diagnostic hurdles, particularly when they are non-functioning. In a case highlighted by Dr. Rida Abbasi, a Gastroenterology SHO at Manchester University NHS Foundation Trust (MFT), a 62-year-old male patient with a history of chronic lymphocytic leukaemia underwent surveillance imaging for adrenal nodules. Cross-sectional imaging revealed multiple new hepatic lesions, peri-duodenal lymphadenopathy, and main pancreatic duct (MPD) dilatation without an identifiable obstructing lesion. Initially, these hepatic lesions appeared cystic and demonstrated benign radiological characteristics, leading to an unsuccessful ultrasound-guided liver biopsy and magnetic resonance imaging that continued to suggest benign pathology.
However, the progressive development and rapid increase in the number and size of these lesions over an 18-month period raised strong clinical concern for an underlying malignant process. Subsequent scans revealed upwards of 30 scattered liver tumors, significant enlargement of surrounding lymph nodes, and marked main pancreatic duct widening reaching the ampulla. To resolve this diagnostic ambiguity, clinicians performed an endoscopic ultrasound (EUS). The examination revealed a hypoechoic pancreatic head with an irregularly dilated and tortuous MPD, alongside atrophic changes in the body and tail. Multiple hepatic cystic lesions containing internal septations were also visualized.
Fine needle aspiration (FNA) obtained from the pancreatic head, liver lesions, and peripancreatic lymph nodes provided the breakthrough. Cytological and histopathological assessment confirmed a well-differentiated neuroendocrine tumour (WDNET), classified as WHO/ENETS grade 2 across all three sites. Immunohistochemistry demonstrated a Ki-67 proliferation index of 8 percent, while a Gallium PET-CT scan confirmed a somatostatin receptor-positive pancreatic head lesion alongside adjacent nodal and hepatic metastatic disease, culminating in a final clinical stage of T1N1M1a. Given the advanced metastatic nature of the disease, the patient commenced four-weekly lanreotide with palliative intent.
Diagnostic Parallels in Gastrointestinal Malignancies
The diagnostic pitfalls associated with cystic hepatic metastases extend beyond pancreatic primaries. In parallel literature indexed by PubMed Central (PMC), investigators documented a separate clinical scenario involving a 53-year-old male who presented with severe hematemesis and melena. Emergency esophagogastroscopy revealed a large ulcer along the lesser curvature of the gastric body. Contrast-enhanced computed tomography (CT) of the abdomen showed hepatomegaly with multiple discrete and confluent cystic lesions involving segments II, III, IV, and VI, featuring fluid debris and daughter cysts that closely mimicked hepatic echinococcosis (hydatid disease).
While metastatic gastrointestinal neuroendocrine tumours classically appear as solid, contrast-enhancing lesions on computed tomography, a small percentage present with cystic architecture. This morphological variance frequently prompts initial misdiagnoses of benign simple cysts, inflammatory collections, or parasitic infections. When medical antiparasitic therapy inevitably failed in the aforementioned gastric case, subsequent surgical excision and histological examination revealed that the suspected hepatic echinococcosis was, in fact, cystic metastases originating from a gastric neuroendocrine tumour. These overlapping radiological features underscore why every complex or progressive cystic lesion of the liver warrants rigorous investigation before finalizing a therapeutic roadmap.
| Clinical Parameter | Pancreatic NET Case (MFT) | Gastric NET Case (PMC) |
|---|---|---|
| Patient Age & Presentation | 62-year-old male; incidental surveillance imaging | 53-year-old male; acute hematemesis and melena |
| Initial Radiological Misinterpretation | Benign polycystic liver disease / benign cysts | Hepatic echinococcosis (parasitic infection) |
| Diagnostic Modality Utilized | Endoscopic Ultrasound (EUS) with FNA | Surgical excision and histopathology |
| Final Pathology | Well-differentiated NET, Grade 2 (Ki-67: 8%) | Malignant gastric ulcer with cystic hepatic metastases |
Contraindications & When to Consult a Doctor
Patients diagnosed with hepatic cystic lesions or those undergoing evaluation for pancreatic and gastrointestinal abnormalities must maintain open communication with their hepatopancreaticobiliary multidisciplinary teams.
Early multidisciplinary assessment and a low threshold for advanced tissue acquisition remain essential when radiological findings are discordant with a patient’s clinical progression.
Conclusion
Atypical presentations of neuroendocrine tumours continue to challenge conventional diagnostic paradigms in gastroenterology and oncology. By demonstrating that metastatic lesions can successfully masquerade as benign polycystic disease or parasitic infections, these documented cases reinforce the necessity of maintaining a broad differential diagnosis. Utilizing advanced endoscopic modalities like endoscopic ultrasound ensures timely staging and appropriate therapeutic intervention for complex hepatobiliary malignancies.
References
- Cureus: Mimicking Polycystic Liver Disease: A Case Report of Innumerable Cystic Hepatic Metastases From a Pancreatic Neuroendocrine Tumour and Diagnostic Role of Endoscopic Ultrasound.
- PubMed Central (PMC): Gastric Neuroendocrine Tumor With Cystic Hepatic Metastases Mimicking Hepatic Echinococcosis. PMC10955437.
- Manchester University NHS Foundation Trust (MFT): Clinical Reports in Hepatopancreatobiliary Medicine.
Disclaimer: This article is intended for informational and educational purposes only and does not constitute medical advice, diagnosis, or treatment. Always seek the advice of a qualified physician or healthcare provider with any questions regarding a medical condition.
