, Volume 43, Issue 3, pp 221–225 | Cite as

Milk of calcium stones: radiological signs and management outcome

  • M. El-ShazlyEmail author
Original Paper


Milk of calcium (MOC) is a rare type of stone that was first described in 1940 by Ludin and Howald who reported MOC in renal cysts. Milk of calcium is a viscous colloidal suspension of calcium salts. Stasis, obstruction and infection are important predisposing factors. Due to a layering effect, characteristic radiological signs especially in CT can help in diagnosis to avoid unsuccessful shock wave lithotripsy. This is the largest reported case series, in which radiological signs by CT scan to predict renal MOC stones, clinical picture and management outcome are described in detail. Cases with suspected renal milk of calcium stones were studied over 7 years (2008–2015). All cases were diagnosed preoperatively by non-contrast CT. Urine cultures were performed in all patients preoperatively. Intra-operative and postoperative findings were reported. Stones retrieved were sent for chemical analysis using an infrared method. Seven cases of milk of calcium renal stones were included in this study. These stones were faint radio-opaque in two cases and radiolucent in five cases. All cases were diagnosed preoperatively with non-contrast CT. Their Hounsfield units (HU) ranged from 114 to 612. All stones were located in a dependent position (gravitational effect) in the posterior aspect of dilated calyces. Five cases exhibited the typical fluid level and two cases demonstrated semilunar (half moon) pattern in the anterior surface of the stones. All cases underwent PCNL with suction and retrieval of soft stones without the need for disintegration. When stones demonstrate a low Hounsfield unit, are arranged in dependent positions within dilated calyces and exhibit fluid level or semilunar pattern on non-contrast CT, milk of calcium stones should be considered. PCNL is an effective modality for management of renal milk of calcium stones.


Milk of calcium Stones Kidney 



I would like to thank Dr Daniele Moon and Professor Elija Kehinde for revising my manuscript. I would like to thank Dr Omar Alhunaidi who helped me in collection of data.

Conflict of interest

I declare that the author of this manuscript has no conflict of interest.


  1. 1.
    Lüdin M, Howald R (1940) Eine eigenartige intrarenale Zyste. Schwiezerisches medizinisches Wochenschr 70:230–232Google Scholar
  2. 2.
    Bude RO, Korobkin MT (1992) Milk of calcium renal cyst—CT findings. Urology 40:149–151CrossRefPubMedGoogle Scholar
  3. 3.
    Vaidyanathan S, Parry R, Parsons KF, Singh G, Soni BM, Sett P (2000) Milk of calcium in the inferior calyx of a hydronephrotic kidney in a tetraplegic patient—a diagnosis to be made before scheduling for extracorporeal shock wave lithotripsy. Spinal Cord 38(5):325–326CrossRefPubMedGoogle Scholar
  4. 4.
    Morjaria A, Balasubramaniam G, Perera S, Almond M (2014) Rapidly developing renal milk of calcium in a patient with myelomonocytic leukaemia. JRSM open. 5(7)Google Scholar
  5. 5.
    Bacchin P, Gasparini G, Paoli G, Di Tonno F (1994) Imposing “calcium milk” lithiasis in giant hydronephrosis. Minerva Urol Nefrol 46(2):133–136PubMedGoogle Scholar
  6. 6.
    Khan SA, Khan FR, Fletcher MS, Richenberg JL (2012) Milk of calcium (MOC) cysts masquerading as renal calculi—a trap for the unwary. Cent European J Urol 65:170–171CrossRefPubMedCentralPubMedGoogle Scholar
  7. 7.
    Uesugi T, Ichikawa T (2006) Atypical findings in a patient with a renal milky stone including a cake of stone. Int J Urol 13(8):1109–1111CrossRefPubMedGoogle Scholar
  8. 8.
    Ys Huang, Huang KH, Chang CC, Liu KL (2011) Milk of calcium in abdomen. Urology 77(3):596–597CrossRefGoogle Scholar
  9. 9.
    Virgili G, Rosi P, Tamburro F, Valitutti M, Torelli F, Vespasiani G, Porena M (1996) Milk of calcium renal stone: echogenic diagnosis. Arch Ital Urol Androl 68(5 Suppl):111–115PubMedGoogle Scholar
  10. 10.
    Fujizuka I, Kudo T, Ohinata M, Kubo T (1990) Milk of calcium renal stone treated with endoscopic extraction: a case report. Hinyokika Kiyo 36(12):1447–1450PubMedGoogle Scholar
  11. 11.
    Mendley WA (1980) Pyelocalyceal diverticula. J Urol 123(1):1–8Google Scholar
  12. 12.
    McCorkell SJ, Hefty TR, Dowling AD (1985) Bilateral milk-of-calcium urine and hydronephrosis. J Urol 133(1):77–78PubMedGoogle Scholar
  13. 13.
    Kikuchi E, Sumitomo M, Hatakeyama N et al (1998) Percutaneous endoscopic marsupialization of a pyelocalyceal diverticulum with milk of calcium stones. Urol Int 60(1):62–65CrossRefPubMedGoogle Scholar
  14. 14.
    Ouegnin GA, Tobelem G, Thomas E, Economou C, Thomas J, Arvis G (1990) Milk of calcium syndrome: a diagnosis to be made before the scheduling of lithotripsy. Consideration a propose of 6 cases. Ann Urol 24(7):552–557Google Scholar
  15. 15.
    Biyani CS, Bhatia V (1993) Renal milk of calcium: review of the literature and report of 5 cases. Urol Int 51(3):171–176CrossRefPubMedGoogle Scholar
  16. 16.
    Ulusan S, Koc Z (2008) Milk of calcium collection in the differential diagnosis of giant renal calculus. Br J Radiol 81:35–36CrossRefGoogle Scholar
  17. 17.
    Heidenreich A, Vorreuther R, Krug B, Moul JW, Engelmann UH (1996) Renal milk of calcium: contraindication to extracorporeal shockwave lithotripsy. Tech Urol 2(2):102–107PubMedGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.Urology DepartmentMenoufia UniversityShebin El-KomEgypt

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