Among pancreatic lesions, differentiatiation between pancreatic neuroendocrine neoplasms (PanNEN) and intrapancreatic accessory spleen (IPAS) is fraught with challenges due to their overlapping features. A retrospective pilot study conducted at Nagoya University Hospital found endoscopic ultrasonography (EUS) to be significant for distinguishing these two conditions.
The study involved 136 patients with pathologically confirmed cases of either non-functional PanNEN or IPAS between August 2006 and December 2022. The researchers evaluated conventional EUS findings, elastographic properties, and enhancement patterns through harmonic imaging to determine their efficacy. The findings indicated significant differences between the two conditions, providing insight on how EUS can streamline diagnoses.
The ability to differentiate PanNEN, which typically requires surgical intervention, from IPAS, which does not, is clinically imperative. Both lesions share characteristics such as similar shapes and early enhancement, complicting pre-surgery identifications. The result of misdiagnosis often leads to unnecessary surgical operations, emphasizing the importance for such differentiation methods.
Conventional EUS findings revealed significant variations, particularly with calcification, which was more prominent for PanNEN compared to IPAS. The data showed, "calcification had significant differences between PanNEN and IPAS (P = 0.006)." This differentiation allowed for relevant diagnosis before surgical consent.
Utilizing EUS components like elastography was innovative; it classified lesions as soft or stiff to provide added clarity. Statistical analysis indicated patients with PanNEN exhibited softer lesions compared to their IPAS counterparts which had stiffer properties (P = 0.029). This information is useful for physicians who need to act quickly when faced with potential surgeries based on mischaracterization.
Enhancement patterns yielded compelling distinctions, with the positive predictive value for IPAS showing 100% criteria of hyperechoic or isoechoic vascular patterns at 300s post-injection, as opposed to only 7% for PanNEN. The researchers highlighted, "It is useful to evaluate calcification with conventional EUS, stiffness with EUS-EG, and enhancement patterns with CH-EUS for differentiation." This multifaceted approach for PanNEN and IPAS diagnostic discrimination suggests improved therapeutic decisions moving forward.
While this study is advantageous, it has some limitations, including its retrospective nature and being conducted at a single center. Nevertheless, its outcomes lay foundational knowledge for future comparative investigations to verify and broaden the applications of EUS techniques.
For patients suffering from pancreatic lesions, improved diagnostic tools can mean the difference between required surgeries and no interventions, potentially leading to less stress and complications during treatment processes. The study recommends utilizing multi-layered EUS methodologies to prevent the negative repercussions of unnecessary surgeries.
This research receives recognition as the first to utilize EUS for differentiative strategies between PanNEN and IPAS and promises to inform clinical practices for enhanced patient outcomes.