Phrygian cap

A 70 year old male with a PMH of gallstone pancreatitis was brought to the ED after a 3 day history of fever, disorientation and abdominal pain. He endorsed emesis and decrease in appetite over the last 3 days. There was concern for possible cholangitis. His labs were significant for leukocytosis with all others within normal limits. A bedside ultrasound was performed in the ED. The findings showed a dilated CBD, thickened gallbladder wall up to 4 mm and pericholecystic fluid. The gallbladder had an interesting appearance in that it appeared septated with a stone lodged in the superior aspect of it. The patient was diagnosed with chronic cholecystitis.

The septated appearance of the gallbladder is known as a phrygian cap and is the most common congenital anomaly of gallbladder appearance with a prevalence of 2-6%. It is a benign variant and was first described by Boyden EA in 1935. Phrygian caps have been confused for both liver masses and gallstones so knowledge of this possible variant is important to keep in mind when forming a differential diagnosis. There is inconclusive evidence that it leads to an increase in cholecystitis. In this patient’s case the gallstone can be seen lodged in the fold of the cap. He was scheduled to undergo a cholecystectomy at a later time period due to the history of gallstone pancreatitis and chronic cholecystitis.

References:
1. Al-Ashqar M, Maliyakkal AK, Shiwani MH, Anwar S. Acalculous Phrygian cap cholecystitis. BMJ Case Reports. 2013;2013:bcr2013009921. doi:10.1136/bcr-2013-009921.
2. Kannan NS, Kannan U, Babu CPG. Congenital Bilobed Gallbladder with Phrygian Cap Presenting as Calculus Cholecystitis. Journal of Clinical and Diagnostic Research : JCDR. 2014;8(8):ND05-ND06. doi:10.7860/JCDR/2014/9057.4724.