Synonyms
- Peritoneal abscesses
- Peritoneal filae
- Peritoneal metastases
- Metastases in the peritoneum
- Metastases in the peritoneum
- Peritoneal carcinomatosis
- Carcinosis peritonei
- Carcinomatous peritonitis
Introduction
Metastases are metastases of an original tumour (primary tumour) that have either directly or via the lymphatic or bloodstream reached another location in the patient’s body. If these metastases are located in or on the peritoneum (a skin that lines the peritoneal cavity and envelops most of the abdominal organs – called peritoneum in Latin), they are peritoneal metastases. They usually originate from tumours of abdominal organs and are the expression of a very advanced disease of the corresponding cancer. Peritoneal metastases are often numerous (multiple), extensive and difficult to distinguish from the healthy surrounding tissue (diffuse). Common tumours of origin of peritoneal metastases are intestinal cancer (colon or rectal carcinoma), ovarian cancer (ovarian carcinoma), stomach cancer (gastric carcinoma), and in the final stage of pancreatic cancer.
Causes
In the course of increasing degeneration (mutative oncogenesis) of cancer cells, they eventually lose their ability to attach themselves to surrounding cells. In advanced cancers, individual cells or even small groups of cells repeatedly detach from the main cell structure of the original tumour (primary tumour). With the blood or lymph stream, sometimes also directly (per continuitatem), they then reach other places where they then settle.
This process is called metastasis. Particularly intestinal cancer (colon or rectal cancer), ovarian cancer (ovarian cancer) and stomach cancer (gastric cancer) tend to metastasise into the peritoneum. Sometimes an increase in the abdominal girth or an accumulation of abdominal fluid (ascites) is noticeable, rarely also complaints of gastrointestinal passage.
Often, however, peritoneal metastases remain without any symptoms, especially in the early stages, so they do not reveal themselves through the manifestation of disease signs, but remain undetected for a long time. Especially when peritoneal metastases have reached a certain size, they can constrict organs of the abdominal cavity. If they squeeze the intestine, in extreme cases this can lead to intestinal obstruction (ileus).
A narrowing of the ureters with subsequent kidney congestion is also conceivable. A local inflammatory reaction of the body in response to the peritoneal metastases can increase the permeability of the intestine for water; as a result, water collects in the abdominal cavity. However, this abdominal dropsy (ascites) can also occur in the context of numerous other diseases.
Diagnosis
Peritoneal metastases do not reveal themselves through conspicuous changes in the patient’s blood and are also difficult to detect through a detailed medical examination. At best, ascites (dropsy) can give rise to suspicion. In the medical interview (anamnesis) symptoms can be asked which could be explained by peritoneal metastases.
Up to this point, the presence of peritoneal metastases cannot be proven, because all symptoms caused by them can also have other causes. At best, a known (or suspected) primary tumour that likes to spread into the peritoneum suggests the suspected diagnosis of peritoneal metastases. Imaging procedures such as CT and MRI often do not help either, and in many cases these cannot detect peritoneal metastases.
If the findings of a radiological examination are inconclusive or even negative, the next diagnostic step is surgery. A so-called laparoscopy, i.e. a surgical procedure in which the abdominal cavity is opened, offers the doctor the opportunity to assess the situation on site and provide a clear answer to the question of whether peritoneal metastases are present. The metastases themselves can cause unspecific abdominal pain or may not be noticeable at all in the early stages.
However, the metastases trigger a number of concomitant symptoms in the abdomen that can lead to pain. As the infestation progresses, a painful feeling of pressure in the abdomen can develop. In addition, abdominal fluid (ascites) may form, which can increase the existing feeling of pressure and cause pain. One should not be afraid of the pain, because in adequate care by a doctor and in the best case additionally by a palliative team, a sufficient pain therapy can be guaranteed, which is aligned to the needs of the patient. Any abdominal fluid that may have formed as a result of the metastases can be drained off in a small operation, which can mean relief for the patient.
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