Part 2: CT characterisation of pancreatic neoplasm: tumour mimics

EUS-guided FNA in Diagnosing Pancreatic Lesions: Strength and Cytological Spectrum

Introduction:

Early and accurate diagnosis is paramount for improving the therapeutic efficacy of pancreatic cancers. Endoscopic ultrasonography–fine needle aspiration (EUS-FNA) cytology has come up with the advantage of an early and accurate diagnosis of pancreatic cancers. This study was conducted to analyze the spectrum of pancreatic lesions cytology, and appraise the diagnostic accuracy of EUS-FNA cytology for pancreatic solid and cystic lesions.

Materials and Methods:

This retrospective study includes 288 EUS-guided pancreatic FNA cases. Clinical data, laboratory tests, cytopathology, histopathology, and imaging reports were retrieved. The final diagnosis was based on EUS-FNA cell block and/or pathology in surgical specimens, with immunohistochemistry support. The results of EUS-guided FNA were compared with the final diagnoses to calculate the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

Results:

Among 288 EUS-guided pancreatic FNA cases, 175 (62.0%) were malignant. The mean age was 57.8 ± 13.5 years and 50.1 ± 13.7 years, and the mean size of the lesion was 4.1 ± 1.8 cm and 2.2 ± 1.1 cm in malignant and benign groups, respectively. Sensitivity, specificity, PPV, and NPV of EUS-FNA cytology for solid malignant lesions were 98.3%, 95.1%, 98.3%, and 95.1%, and those for cystic lesions were 88%, 92.3%, 100%, and 100%. Diagnostic accuracy of EUS-FNA cytology for solid and cystic pancreatic lesions is 97.4% and 95.0%, respectively. In conclusion of the above; diagnosis of pancreatic solid and cystic malignancy can be assigned from a composite of the EUS-FNA cytology, cell block preparation and immunohistochemistry Diagnosis of pancreatic solid and cystic malignancy can be assigned from a composite of the EUS-FNA cytology, cell block preparation, and immunohistochemistry.

Isolated pancreatic heamorrhage in association with anticoagulation

Haemorrhage is the primary complication of anticoagulation therapy with the gastrointestinal, urinary and nasal tracts the most common sites of bleeding. Haematoma within solid organs is uncommon especially in the absence of blunt trauma. We describe two patients on long term Warfarin therapy who developed focal haematomas within the pancreas. To the best of our knowledge these are the first isolated unprovoked focal pancreatic hematoma cases reported in the literature. The non-specific clinical symptoms and confusing radiological features mimicked pancreatic malignancy and this led to misdiagnosis in the one patient who underwent unnecessary surgical exploration. The haematoma was correctly identified in the second patient who was managed conservatively and had an uneventful recovery.

Mimics of pancreatic ductal adenocarcinoma

Several uncommon primary pancreatic tumors, inflammatory conditions, metastasis to the pancreas and peripancreatic masses can mimic the appearance of pancreatic ductal adenocarcinoma (PDA). Differentiation between these lesions and PDA can be challenging, due to the overlap in imaging features; however, familiarity with their typical imaging features and clinical presentation may be helpful in their differentiation, as in some cases, invasive diagnostic tests or unnecessary surgery can be avoided. The different pathologies that can mimic PDA include inflammatory conditions such as the various forms of pancreatitis (chronic-focal mass-forming, autoimmune and groove pancreatitis), pancreatic neuroendocrine tumors, solid pseudopapillary tumors, metastasis (solid non-lymphomatous and hematologic), congenital variants (annular pancreas), as well as peripancreatic lesions (accessory spleen, adrenal masses, duodenal masses, lymph nodes and vascular lesions), and certain rare pancreatic tumors (e.g., acinar cell tumors, solid serous tumors, hamartoma and solitary fibrous tumors). The clinical presentation and imaging features of the most commonly encountered mimics of PDA are discussed in this presentation with representative illustrations.