Objectives: Pancreatic cystic neoplasms (PCNs), particularly intraductal papillary mucinous neoplasms (IPMNs), present a challenge for their potential malignancy. Despite promising biomarkers like CEA, amylase, and glucose, our study investigates whether metabolic indices in blood and cystic fluids (CFs), in addition to lymphocyte subsets and hematopoietic stem/progenitor cells (HSPCs), can effectively differentiate between high- and low-risk PCNs. Materials and Methods: A total of 26 patients (11 males, mean age 69.5 ± 9 years) undergoing Endoscopic Ultrasound-guided Fine Needle Aspiration were consecutively enrolled. Analyses included blood, serum, and CF, assessing glucose, CEA, cholesterol (total, HDL, and LDL), and total proteins. Flow cytometry examined immunophenotyping in peripheral blood and cystic fluids. Mass spectrometry was used for the metabolomic analysis of CF. Sensitivity, specificity, and ROC analyses evaluated discriminatory power. Results: A total of 25 out of 26 patients had IPMN. Patients were categorized as low or high risk based on multidisciplinary evaluation of clinical, radiological, and endoscopic data. High-risk patients showed lower CF total proteins and LDL cholesterol (p = 0.005 and p = 0.031), with a marked reduction in CF lymphocytes (p = 0.005). HSCPs were absent in CF. In blood, high-risk patients showed increased non-MHC-restricted cytotoxic T cells (p = 0.019). The metabolomic analysis revealed significantly reduced middle and long-chain acyl carnitines (AcCa) and tryptophan metabolites in high-risk patients. ROC curves indicated comparable discriminant abilities for CF lymphocytes (AUC 0.868), CF total proteins (AUC 0.859), and CF LDL cholesterol (AUC 0.795). The highest performance was achieved by the AcCa 14:2 and 16:0 (AUC: 0.9221 and 0.8857, respectively). Conclusions: CF levels of glucose, CEA, LDL cholesterol, and total proteins together with lymphocyte counts are easy translational biomarkers that may support risk stratification of PCNs in IPMN patients and might be endorsed by metabolomic analysis. Further studies are required for potential clinical integration.

Breast Implant-Associated-Anaplastic Large Cell Lymphoma (BIA-ALCL) is a rare T-cell non-Hodgkin lymphoma associated with breast prosthetic implants and represents a diagnostic challenge. The National Comprehensive Cancer Network (NCCN) guidelines, updated in 2024, recommend for diagnosis an integrated work-up that should include cell morphology, CD30 immunohistochemistry (IHC), and flow cytometry (FCM). CD30 IHC, although the test of choice for BIA-ALCL diagnosis, is not pathognomonic, and this supports the recommendation to apply a multidisciplinary approach. A close collaboration between pathologists and laboratory professionals allowed the diagnosis of three BIA-ALCLs, presented as case reports, within a series of 35 patients subjected to periprosthetic effusions aspiration from 2018 to 2023. In one case, rare neoplastic cells were identified by FCM, and this result was essential in leading the anatomopathological picture as indicative of this neoplasm. In fact, the distinction between a lymphomatous infiltrate from reactive cells may be very complex in the cytopathology and IHC setting when neoplastic cells are rare. On the other hand, one limitation of FCM analysis is the need for fresh samples. In this study, we provide evidence that a dedicated fixative allows the maintenance of an unaltered CD30 expression on the cell surface for up to 72 h.