Objective: To analyze the composition of prostatic calculus in patients with BPH and explore its pathogenic factors and histopathological characteristics.
Methods: Strictly following the inclusion and exclusion criteria, we included in this retrospective study 580 cases of bipolar transurethral plasma kinetic prostatectomy (TUPKP) performed in our hospital from May 2015 to May 2019, analyzed the histopathological and calculus-composition features of the patients with BPH complicated by prostatic calculi (the BPH+PC group) and the histopathological data of those with BPH only (the BPH group). We compared the related factors between the two groups of patients and performed uni- and multivariate logistic regression analyses of the data on those in the BPH+PC group.
Results: The incidence rate of chronic inflammation was significantly higher in the BPH+PC than in the BPH group (83.1% vs 61.1%, P < 0.05), 90% of the cases moderate to severe and 81% with inflammatory cells mainly distributed in the prostate gland in the BPH+PC group, and 74% with inflammatory cells chiefly distributed in the prostate gland and stroma in the BPH group, with statistically significant difference between the two groups (P < 0.05). Prostatic calculi were found in 302 (52.1%) of the patients, including 71 cases of simple calculi (23.5%) and 231 cases of mixed calculi (76.5%). As for the chemical composition, calcium oxalate was detected in 212 cases (70.2%), carbonate apatite in 206 (68.2%), magnesium ammonium phosphate in 158 (52.3%), and uric acid calculi in 19 (6.3%). The calculus composition was not correlated with the age of the patients. There were statistically significant differences between the two groups of patients in age, prostate volume and IPSS (P < 0.05), but not in the PSA level, postvoid residual urine volume (PRV) or maximum urinary flow rate (Qmax) (P > 0.05). Logistic regression analyses showed that prostatic calculus was significantly correlated with chronic inflammation of the prostate, the patient's age and IPSS (P < 0.05) but not with the PSA level, PRV or Qmax (P > 0.05).
Conclusions: Prostatic calculus has a high incidence in BPH patients and varies widely in composition, chiefly consisting of calcium oxalate and carbonate apatite. The major factors contributing to prostatic calculi include chronic inflammation of the prostate (primarily the severe type), age and BPH. Prostate calculi may aggravate lower urinary tract symptoms, especially urinary storage symptoms, in patients with BPH, but not significantly affect the PSA level.？.
Keywords: benign prostatic hyperplasia; chronic inflammation; crystalline composition; pathological study; prostatic calculus.