Pancreatic Incidentalomas: A Management Algorithm for Identifying Ectopic Spleens

The Rate of Avoidable Pancreatic Resections at a High-Volume Center: An Internal Quality Control and Critical Review

BACKGROUND

The incidence of benign diseases among pancreatic resections for suspected malignancy still represents a relevant issue in the surgical practice. This study aims to identify the preoperative pitfalls that led to unnecessary surgeries at a single Austrian center over a twenty-year period.

METHODS

Patients undergoing surgery for suspected pancreatic/periampullary malignancy between 2000 and 2019 at the Linz Elisabethinen Hospital were included. The rate of "mismatches" between clinical suspicion and histology was considered as primary outcome. All cases that, despite that, fulfilled the indication criteria for surgery were defined as minor mismatches (MIN-M). Conversely, the true avoidable surgeries were identified as major mismatches (MAJ-M).

RESULTS

Among the 320 included patients, 13 (4%) presented with benign lesions at definitive pathology. The rate of MAJ-M was 2.8% (n = 9), and the most frequent causes of misdiagnoses were autoimmune pancreatitis (n = 4) and intrapancreatic accessory spleen (n = 2). In all MAJ-M cases, various mistakes within the preoperative workup were detected: lack of multidisciplinary discussion (n = 7, 77.8%); inappropriate imaging (n = 4, 44.4%); lack of specific blood markers (n = 7, 77.8%). The morbidity and mortality rates for mismatches were 46.7% and 0.

CONCLUSION

All avoidable surgeries were the result of an incomplete pre-operative workup. The adequate identification of the underlying pitfalls could lead to minimize and, potentially, overcome this phenomenon with a concrete optimization of the surgical-care process.

WFUMB Position Paper-Incidental Findings, How to Manage: Spleen

The World Federation for Ultrasound in Medicine and Biology (WFUMB) is addressing the issue of incidental findings (IFs) with a series of publications entitled "Incidental Imaging Findings-The Role of Medical Ultrasound." IFs are less commonly encountered in the spleen than in many other abdominal organs but remain a frequent dilemma in clinical practice. A histological diagnosis is rarely necessary for patient management. Many IFs, such as secondary spleens and splenic cysts, are harmless and do not require any further investigation. The diagnosis of many other focal splenic lesions is, however, often problematic. The following overview is intended to illustrate a variety of incidentally detected spleen pathologies such as size variants, shape variants, secondary spleens, focal splenic lesions and splenic calcifications. It should aid the examiner in establishing the diagnosis. Moreover, it should help the ultrasound practitioner decide which pathologies need no further investigation, those requiring interval imaging and cases in which immediate further diagnostic procedures are required.

Pancreatic nodule positive for 68-Ga-DOTAPEPTIDE-PET: NET or ectopic spleen? The importance of a good differential diagnosis

Background

Accessory spleen is a congenital defect in which splenic tissue is present outside the spleen. In 20% of cases, accessory spleen is localized within the pancreatic tail, a condition known as IPAS. The identification of this benign anomaly, which affects about 2% of general population, is not easy because it is often mistaken for a pNET which is more common, at around 5%. A 68-Ga-DOTAPEPTIDE-PET normally identifies pNETs with high rate of sensitivity and specificity, but in some conditions, it produces false positives, including IPAS.

Materials and tools

A clinical case we recently encountered, prompted us to review the available medical literature on the topic. Typing “intrapancreatic accessory spleen” into PubMed database and limiting research to the last 10 years yielded 121 results from which we selected the most relevant articles for decision-making, with a brief explanation of the reasons for selecting those. Our analysis focused on the most critical and least descriptive articles, those which clearly indicated the importance of differential diagnosis by promoting the use of advanced investigations in case of pancreatic nodule suspected for IPAS. Ultimately, our objective was to update the available guidelines recommendations.

Discussion and conclusions

Despite concern in the medical literature, a differential IPAS diagnosis is still subordinate to other clinical, radiological, nuclear medicine, and cytological criteria. After reviewing the literature, we recommend that IPAS should always be considered as a possibility before diagnosis of pNET is made. IPAS should be suspected in the presence of the following findings: asymptomatic pancreatic nodule found incidentally, absence of laboratory findings of NETs, localization in the pancreatic tail, between 1 and 3 cm in size with well-defined margins, homogeneous enhancement, and similar attenuation to the spleen on CT and MRI. In these cases, the use of advanced investigations beyond 68-Ga-DOTAPEPTIDE-PET must be systematic. The recognition of IPAS is not only a diagnostic refinement, but it also avoids unnecessary surgery for the patient. 

Heterotopic accessory spleen with squamous epithelial cyst in pancreas mimicking other pancreatic tumor: a case report

A 49-year-old female undergoing a periodic health examination at other hospital revealed a mass in the tail of pancreas. The patient denied any personal history of surgery except subtotal hysterectomy because of multiple myomas in uterus 7 years ago, family history of abdominal cancer and trauma. Physical examination and laboratory finding (including tumor marker) were unremarkable. Chest X-ray result was normal. Contrast enhanced ultrasound (CEUS) examination showed a well-defined hypoechoic pancreatic mass which was suggestive of solid pseudopapillary tumor. Contrast enhanced computed tomography (CE-CT) of the abdomen revealed a mass of hypodensity suggestive of intraductal papillary mucinous neoplasm. Because of the risk of bleeding and exclusion of surgical contraindications, patient underwent laparoscopic surgery. Intraoperatively, a solid mass was identified in the tail of pancreas, the intraoperative frozen pathological examination suggested a heterotopic accessary spleen (HAS) with squamous epithelial cyst. Partial pancreatectomy was performed. The uniqueness of this case is that the spleen can be ectopic to the pancreas, what is even more unexpected is that the HAS undergone cystic change. When encountering a pancreatic mass, we need to think about the possibility of HAS. In conclusion, it is important to diagnose HAS with squamous cyst in the pancreatic tail presenting as other pancreatic masses.

Intrapancreatic accessory spleen false positive to 68Ga-Dotatoc: case report and literature review

Background

Intrapancreatic accessory spleen (IPAS) is an uncommon finding of pancreatic mass. Differential diagnosis with pancreatic tumor, especially with non-functional neuroendocrine tumor (NF-NET), may be very hard and sometimes it entails unnecessary surgery. A combination of CT scan, MRI, and nuclear medicine can confirm the diagnosis of IPAS. 68-Ga-Dotatoc PET/CT is the gold standard in NET diagnosis and it can allow to distinguish between IPAS and NET.

Case presentation

A 69-year-old man was admitted to our hospital for an incidental nodule in the tail of the pancreas with focal uptake of 68-Ga-dotatate at PET/CT. NET was suspected and open distal splenopancreatectomy was performed. Pathologic examination revealed an IPAS.

Conclusion

This is the second IPAS case in which a positive 68Ga-Dotatoc uptake led to a false diagnosis of pancreatic NET. Here is a proposal of a literature review.