If we may judge from the reports in the literature, of which there are only a few authentic cases, primary carcinoma of the cystic duct is extremely rare. This tumor may be considered especially rare when compared with carcinoma of the gallbladder and of the hepatic and common bile ducts. The rarity of this neoplasm has been pointed out by most authors writing on the subject. Few cases, indeed, occur in the surgical experience of one person, and these are usually published as isolated case reports. For this reason, also, statistical studies on the frequency of occurrence of this lesion are in most instances inaccurate.
The occasional observation at operation or autopsy of a carcinoma of the cystic duct may evoke little comment or surgical curiosity. Such tumors are sometimes reported by the surgeon or pathologist as an afterthought, as though they were of no surgical or pathological significance, and
RABINOVITCH J, ARLEN M, GRAYZEL D, ROBERTS M, RABINOVITCH P. Primary Carcinoma of the Cystic DuctReport of Two Cases. AMA Arch Surg. 1960;80(3):424-433. doi:10.1001/archsurg.1960.01290200068011