Abstract
We report a unique case of limy bile without any identifiable cause of gallbladder stasis and with an unusual ultrasound appearance.

Introduction
Limy bile or milky bile is a rare disorder in which the gallbladder lumen is filled with a semisolid radio-opaque material composed primarily of calcium carbonate. The aetiology is unknown, although gallbladder stasis is believed to be a prerequisite.1 The condition tends to occur when there is gradual obstruction of the cystic or common bile duct e.g. chronic pancreatitis or carcinoma of pancreas.²

Case Report
A twenty five year old female patient presented with right upper abdominal pain. She had experienced similar two episodes in the past three months. The pain increased after consuming fatty food. There was no history of jaundice, fever or chills and rigors. Ultrasonography done elsewhere was reported as showing multiple gallstones. The patient wished to have non-operative treatment for her problem.

On examination the patient was obese with tenderness over the right hypochondrium. Murphy’s sign was negative and there was no hepatomegaly.
A plain radiograph of the abdomen taken revealed a spindle shaped radio-opaque shadow on the right side of D12 and L1 vertebrae beneath the hepatic shadow (Fig. 1).

On ultrasonography gallbladder showed multiple mobile calculi moving with the change in patient position, the largest one measuring 6 mm, and multiple immobile echogenic foci close to the wall of gallbladder, ? multiple polyps (Fig. 2). The gallbladder measured 6.8 cm in length and its wall thickness was reported as 1.2 mm. Common bile duct measured 4 mm in diameter with no evidence of any calculi or obstruction. Liver and pancreas were normal.

Although the plain radiograph gave a diagnosis of limy bile, the ultrasound features prompted a diagnosis of multiple gallstones with possibility of multiple polyps.

Repeated episodes of pain, sonographic evidence of multiple gallbladder polyps, wall thickness of 1.2 mm were indications for surgical management. Cholecystectomy was performed. Intra operatively the patency of the common bile duct was checked by manual palpation. A plain radiograph of the post operative specimen showed the gallbladder to be uniformly radio-opaque (Fig. 3).

A biochemical analysis of the bile obtained revealed that its total calcium content was 12.6 mmol/l.

Post operative specimen of the gallbladder showed a whitish sediment in the bile probably due to calcium deposition. No stone was found as had been visualized on ultrasonography. The mucosa of the gallbladder was hypertrophied and thrown into folds leading to the appearance of multiple polyps on ultrasonography.

Microscopic examination showed features of chronic cholecystitis with surface erosion, congestion and mononuclear inflammatory infiltrate of the mucosa and mild fibrosis of the muscularis.

Fig. 1 : Plain radiograph of the abdomen showing a spindle shaped radio-opaque shadow on the right side of D12 and L1 vertebrae beneath the hepatic shadow.	Fig. 2 : US shows multiple gallbladder calculi and multiple echogenic foci close to the gallbladder wall? Multiple polyps.

Fig. 3 : Plain radiograph of post-operative specimen shows the gallbladder to be uniformly radio-opaque.

Discussion
Limy bile or milk of calcium cholecystitis was first described in 1911 and only 300 cases had been reported until 1988.³

It is a rare disease predominantly of the adults. The man:woman ratio is 1:3.³

The term designates a pathologic accumulation of calcium carbonate in the gallbladder, much rarer in the common bile duct as well. Only 20 cases of limy bile in the common bile duct have been reported so far.⁴

Calcium in the bile may be liquid or it may form a paste like mass. Both may be seen on the plain radiograph of the abdomen. The presence of this condition in the gallbladder is always associated with biliary lithiasis and the obstruction of cystic duct.5 The presence of limy bile in common bile duct is due to migration of impacted stone and calcareous material deposited in the gallbladder.⁵

Normal mean values of the total and free calcium in human gallbladder bile is reported to be 6.05 ± 0.31 mmol/l and 1.28 ± 0.05 mmol/l respectively.6 In our patient, the total calcium in the gallbladder bile was found to be 12.6 mmol/l; almost twice the normal amount.

Previous studies have shown that bilirubin, cholesterol and phospholipids incremently interfere with calcium carbonate precipitation from super saturated solutions calcium chloride and sodium bicarbonate through preferential formation of soluble calcium complex. Lower concentrations of these inhibitory factors have been observed in the gallbladder bile of patients with calcified gallstones.

The patient may be symptom free. When present the symptoms may be very mild or as an acute biliary pain, transient jaundice and mild attacks of pancreatitis. Our patient had three episodes of acute biliary pain in the months.

Limy bile is best elucidated by plain abdominal radiographs.⁷ On plain abdominal radiographs limy bile appears as an oval or spindle shaped radio-opacity below the liver margin. It is revealed more clearly in plain radiograph than if the gallbladder has been visualized by cholecystography.²
It results in a variety of sonographic appearances. Both an echogenic flat fluid-fluid level and a convex shadowing meniscus pattern have been reported. Occasionally the echogenicity of milk of calcium resembles sludge, although it can be distinguished from sludge by the presence of gradual acoustic shadowing.⁸

A close differential diagnosis of limy bile is porcelain gallbladder which is characterized histologically by flakes of dystrophic calcium within chronically inflamed and fibrotic wall of gallbladder. On plain radiography it shows curvilinear (muscularis) or granular (mucosal) calcifications in segment of wall or the entire wall. Sonographic appearance is that of highly echogenic shadowing curvilinear structure in gallbladder fossa or echogenic gallbladder wall with little acoustic shadowing. Traditionally it is differentiated from limy bile by its inability to contract on gallbladder contractility test with cholecystokinin or in responce to a fatty meal.

Ultrasonographic examination of our patient showed features suggestive of multiple calculi and possibly multiple polyps, both of which eventually proved to be negative in the post operative specimen examination.

The strategy for managing patients with limy bile is individualized based on symptoms, the clinical conditions, and the location of limy bile, and any associated biliary stones or lesions causing cystic duct obstruction.

The case is thus presented for its uniqueness in that calcium carbonate precipitation appears to have occurred in the absence of gallbladder obstruction and for its unusual appearance on ultrasonography.

References

1. Naryshkin S, Trotman BW, Raffensperger EC. Milk of calcium bile. Evidence that gallbladder stasis is a key factor. Dig Dis Sci 1987; 32 (9) : 1051-5.
2. Charles V Mann, Russell RCG, Norman S Williams. The gallbladder and bile ducts. In: Bailey and Love’s Short Practice of Surgery, 22nd ed. London: Chapman and Hall 1995; 47 : 737.
3. Sava G, Millot P, Becmeur F, Vaxman F, Grenier JF. Limy bile syndrome. Study of a case with double localization in the gallbladder and common bile duct. Gastroenterol Clin Biol 1988; 12 (2) : 156-9.
4. Takatori Y, Yamauchi K, Negoro Y, et al. Limy bile syndrome complicated with primary hyperparathyroidism. Intern Med 2003; 42 (1) : 44-7.
5. Moreaux J, Roux JM. Limy bile. A surgical experience in 16 patients. Gastroenterol Clin Biol 1994; 18 (6-7) : 550-5.
6. Shiffman ML, Sugerman HJ, Kellum JM, Moore EW. Calcium in human gallbladder bile. J Lab Clin Med 1992; 120 (6) : 875-84.
7. Derrick F Martin, Hans-Ulrich Laasch. The biliary tract. In : Grainger and Allison’s diagnostic radiology. 4th ed. London : Churchill Livingstone, 2001; 56 : 1282.
8. Faye C Laing. The gallbladder and bile ducts. In: Carol M Rummack, Stephaine R Wilson, J William Charboneau: Diagnostic ultrasound. 2nd ed. Missouri; Mosby. 1998; 6 : 198.