Why in meig and pseudomeig syndrome there is right side pleural effusion?

Why in meig and pseudomeig syndrome there is right side pleural effusion?

In Meigs’ syndrome and pseudo-Meigs’ syndrome, the presence of a right-sided pleural effusion is often observed. These syndromes involve the triad of ovarian fibroma or fibroma-like tumors, ascites, and pleural effusion. However, the specific reason for the predominance of right-sided pleural effusion in these syndromes is not entirely clear, and the exact mechanisms may vary.

Here are a few potential explanations:

  1. Anatomical considerations: The right hemidiaphragm has a higher position compared to the left due to the presence of the liver, which occupies the right upper quadrant of the abdomen. This anatomical arrangement may predispose the right pleural space to accumulate fluid more easily, particularly when there’s increased intra-abdominal pressure from ascites.
  2. Lymphatic drainage: The lymphatic drainage patterns of the peritoneal cavity and pelvis may contribute to the preferential accumulation of fluid on the right side. Lymphatic vessels from the pelvic organs, including the ovaries, predominantly drain into the right lymphatic duct and thoracic duct. Any obstruction or disruption of lymphatic flow due to the ovarian tumor or ascites could lead to accumulation of fluid in the right pleural space.
  3. Hemodynamic factors: Increased intra-abdominal pressure from ascites can cause a shift in fluid across the diaphragm into the pleural space, a phenomenon known as “fluid shift.” The liver’s position on the right side may further accentuate this process, leading to a higher propensity for pleural effusion on the right side.
  4. Tumor mass effect: The presence of an ovarian tumor, such as a fibroma or fibroma-like tumor, may exert pressure on adjacent structures, including the diaphragm and lymphatic vessels. This pressure could disrupt normal fluid dynamics and lymphatic drainage, contributing to the formation of pleural effusion, which may be more pronounced on the right side due to anatomical factors.

It’s important to note that while right-sided pleural effusion is typical in Meigs’ syndrome and pseudo-Meigs’ syndrome, it’s not an absolute rule, and left-sided or bilateral effusions can also occur. The underlying mechanisms are complex and may involve a combination of anatomical, lymphatic, and hemodynamic factors interacting with the tumor and associated ascites.