Background: Estimation of plasma cell infiltrates in bone marrow aspirates (BMA) and bone marrow biopsy (BMB) is a standard method in the diagnosis and monitoring of multiple myeloma (MM). Plasma cell fraction in the bone marrow is therefore critical for the classification and optimal clinical management of patients with plasma cell dyscrasias. The aim of the study was to compare the percentage of plasma cells obtained by both methods with the patient clinical parameters and survival. Methods: This retrospective study included BMA and BMB of 59 MM patients. The conventional differential count was determined in BMA to estimate the percentage and cytologic grade of plasma cells. The pattern of neoplastic infiltration and percentage of plasma cells were estimated on CD138 immunostained BMB slides microscopically and by computer-assisted image analysis (CIA). Results: Significantly higher values of plasma cell infiltrates were observed in pathologist (47.7 ± 24.8) and CIA (44.1 ± 30.6) reports in comparison with cytologist analysis (30.6 ± 17.1; P < 0.001 and P < 0.0048, respectively). BMB assessment by pathologist counting and using CIA showed strongest correlation (r = 0.8; P < 0.0001). Correlation was also observed between the pathologist and cytologist counts (r = 0.321; P = 0.015) as well as comparing the percentage of plasma cells in BMA and CIA (r = 0.27; P = 0.05). Patients with clinical stage I/II had a significantly lower CIA plasma cell count than those with clinical stage III (P = 0.008). Overall survival was shorter in patients with more than 25% of atypical plasma cell morphology estimated in BMA (P = 0.05) and a higher percentage of tumor cell infiltrates estimated by the pathologist and CIA (P = 0.0341 and P = 0.013, respectively). Conclusion: Study results suggested the combined analyses to be useful as a routine procedure to achieve more accurate and informative diagnostic data.

Background: Balkan nephropathy (BEN) is an environmental form of aristolochic acid nephropathy (AAN) strongly associated with upper urinary tract urothelial carcinoma (UTUC). Clinical diagnosis remains challenging, and misclassification is frequent. The study reassessed BEN diagnoses in kidney transplant recipients from rural farming areas who did not undergo prophylactic bilateral nephroureterectomy and evaluated post-transplant outcomes. Methods: In this retrospective single-centre study, we analysed 12 kidney transplant recipients from rural Balkan farming regions. BEN diagnoses were reevaluated according to international consensus criteria. Key endpoints included patient and graft survival, post-transplant clinical course, and UTUC characteristics. Results: Upon reassessment, three of the six patients initially diagnosed with BEN were reclassified as having BEN. Among the remaining six patients, four were reclassified as having sporadic BEN. Overall, only 33% of patients had a diagnosis concordant with their admission records. During a median follow-up of 6.8 years (IQR 2.1–15.8), UTUC developed in seven out of 12 patients. The UTUC cases were predominantly high-grade and multifocal, and they were identified as the leading cause of death. Five-year patient and graft survival rates were 71% and 100%, respectively. Conclusions: BEN is frequently misdiagnosed or misclassified in kidney transplant candidates from rural farming areas. Despite excellent graft survival, the high incidence of post-transplant urothelial carcinoma underscores the necessity of accurate diagnosis and the consideration of prophylactic bilateral nephroureterectomy. Lifelong intensive surveillance is essential not only for patients from established BEN regions but also for individuals from other rural farming areas at risk for sporadic BEN.