Iranian Journal of Nuclear Medicine

Iranian Journal of Nuclear Medicine

Displaced bladder stone mimics primary prostate cancer/bone metastasis, requiring a SPECT/CT whole-body bone scan for accurate diagnosis

Document Type : Case Report

Authors
Mahdi Haghighatafshar
Farshad Babaeipour
Saeed Amiri Gheshlaghi
Department of Nuclear Medicine, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
10.22034/irjnm.2025.130086.1692
Abstract
A 69-year-old male patient diagnosed with prostate adenocarcinoma underwent whole-body bone scintigraphy utilizing [99mTc]Tc-methylene diphosphonate (MDP) for initial staging. During the procedure, an unexpected focal uptake of the radiotracer was noted, which appeared to resemble metastasis to the pubic bone or prostate cancer. However, this finding was ultimately determined to be due to a displaced bladder stone located within the prostatic urethra. This case highlights the importance of reviewing the patient's previous imaging studies, utilizing SPECT/CT imaging, and considering urinary tract stones as a potential differential diagnosis when abnormal radiotracer uptake is detected in the pelvic region below the bladder.
Keywords
Prostatic urethra stone
Prostate cancer
Bone scintigraphy
SPECT/CT
Differential diagnosis
Subjects
  1. Kabunda J, Gabela L, Kalinda C, Aldous C, Pillay V, Nyakale N. Comparing 99mTc-PSMA to 99mTc-MDP in prostate cancer staging of the skeletal system. Clin Nucl Med. 2021 Jul 1;46(7):562-8.
  2. Eftekhari M, Fard-Esfahani A, Haghighatafshar M, Keyvan A, Beiki D, Aghahosseini F, Emami-Ardekani A, Saghari M. Bone scan with incidental visualization of the entire colon. Iran J Nucl Med. 2010; 18(2): 56-9.
  3. Mohd Hashim MH, Shukor S, Azizi MH. Giant prostatic stones and a massive bladder stone leading to obstructive uropathy: a rare case report. Cureus. 2023 Aug 8;15(8):e43176.
  4. Singh S, Martin E, Tregidgo HFJ, Treeby B, Bandula S. Prostatic calcifications: quantifying occurrence, radiodensity, and spatial distribution in prostate cancer patients. Urol Oncol. 2021 Oct;39(10):728.e1-6.
  5. Cai T, Tessarolo F, Caola I, Piccoli F, Nollo G, Caciagli P, Mazzoli S, Palmieri A, Verze P, Malossini G, Mirone V, Bjerklund Johansen TE. Prostate calcifications: A case series supporting the microbial biofilm theory. Investig Clin Urol. 2018 May;59(3):187-93. 
  6. Suh JH, Gardner JM, Kee KH, Shen S, Ayala AG, Ro JY. Calcifications in prostate and ejaculatory system: a study on 298 consecutive whole mount sections of prostate from radical prostatectomy or cystoprostatectomy specimens. Ann Diagn Pathol. 2008 Jun;12(3):165-70.
  7. Smolski M, Turo R, Whiteside S, Bromage S, Collins GN. Prevalence of prostatic calcification subtypes and association with prostate cancer. Urology. 2015 Jan;85(1):178-81.
  8. Koga S, Arakaki Y, Matsuoka M, Ohyama C. Urethral calculi. Br J Urol. 1990 Mar;65(3):288-9.
  9. Paulk SC, Khan AU, Malek RS, Greene LF. Urethral calculi. J Urol. 1976 Oct;116(4):436-9.
  10. Sharfi AR. Presentation and management of urethral calculi. Br J Urol. 1991 Sep;68(3):271-2.