Causes of pancreatic cyst

Typically, according to their origin and morphological features, there are four types of pancreatic cysts.

The first type is ontogenetic cysts, which are a developmental defect, often such cysts are multiple and often combine with polycystosis of other organs (lungs, kidneys, liver, etc.), thus representing congenital polycystic disease. Cysts are usually lined with a single-row cubic epithelium, and the contents are serous and do not contain enzymes.

The second type of cyst is proliferative; their occurrence is due to the proliferation of ductal epithelium, the lumen of which is significantly enlarged. These cysts develop against the background of pancreatic tissue fibrosis and are multi-chamber cavities of the cystadene type. Sometimes this disease is called "cystic fibrosis" of the pancreas, and some cases are difficult to distinguish from cystic fibrosis.

The next type of pancreatic cyst is retentional, arising from compression (scar, tumor, cyst), malignant tumor growth or blockage (for example, by a stone) of the duct or several pancreatic ducts. In the occurrence of such cysts, it is believed that concomitant lymphostasis plays a certain role. Cysts of this type are often solitary and have large dimensions (up to 10 cm or more), but they can also be multiple small, representing a kind of limited conglomeration of cysts. The contents of the cysts are serous or colloidal.

And, finally, the fourth kind of cysts are false cysts, sometimes also called pseudocysts. They occur in patients who underwent a severe form of hemorrhagic pancreatitis, in the zone or zones of necrosis of pancreatic tissue, in some cases - abscesses (if the abscess did not break through the fistula in any nearby organ: the stomach, duodenum, pleural cavity and other). In the foci of necrosis of pancreatic tissue manifesting during hemorrhagic pancreatitis, in the next few hours (with "favorable" flow, i.e., if the patient does not die from this acute severe disease), fibrin first falls out, then a granulation inflammatory shaft around the foci of necrosis, which is then converted into a dense fibrous capsule. The number and size of pseudocysts in different patients may be different. With chronic recurrent pancreatitis, after severe exacerbations, foci of necrosis may reappear and new cysts may appear. But more often still there is one or two cysts, less often - multiple pseudocysts. Sometimes such pseudocysts reach very large sizes, pushing aside neighboring organs (stomach, transverse colon, spleen). The dimensions of the pseudocysts are determined by a number of factors: the size of the necrosis foci formed by the decay of the tissue in these areas with osmotic-active substances that promote the "pulling" of the fluid from the surrounding tissue (interstitial fluid, lymph), with the blood flowing into the cyst when a large enough blood vessel arises. Finally, keeping close to the duct (or ducts), through which pancreatic juice is released into the cyst, is released from healthy areas of the tissue, and the possibility of outflow of cyst contents to the larger ducts and duodenum is of great importance. It is believed that after acute hemorrhagic (necrotic) pancreatitis, one pseudocyst or a few are formed in about half the cases, especially often with pancreatitis of alcoholic nature. It should be noted here that cysts of the first three types are much less common: according to the data of different authors, 0.01-0.07% of cases.

Do not forget and other reasons for the formation of pancreatic cysts - due to abdominal trauma, the development of echinococcus (the latter, however, in this body are rare), etc.

[1], [2], [3], [4], [5]