Pathological terminology

Unfortunately, medical terms can sometimes be confusing and there are often multiple names for the same condition. Pseudomyxoma peritonei (PMP) is no exception and has been classified in different ways over the years. The current classification, endorsed by the World Health Organization (WHO), is shown in the Table. It uses the term “mucinous carcinoma peritonei”, which is the same as “PMP”.

Acellular mucin can occur in PMP, but also in ruptured ovarian cysts, causing it to accumulate in the peritoneal cavity. However, removing the ovarian cyst cures it. A hallmark is acellular mucin in the peritoneal cavity without epithelial cells. It is not graded.

A crash course in medical terms

If you are not familiar with the words used by doctors when describing tumours, here are some definitions:

• benign
  Cannot spread to distant parts of the body
• malignant
  Can spread to distant parts of the body
• tumour
  A mass due to autonomous growth of cells, whether benign or malignant
• neoplasm
  Another word for tumour
• cancer
  A malignant tumour
• lesion
  Anything abnormal on or in the body, not just neoplasms

Neoplasms are classified according the type of normal cell they resemble. For example, adenocarcinoma is a type of cancer resembling glands (adeno = gland and carcinoma = cancer of lining cells). Tumours are called mucinous if more than 50% of the mass consists of mucin.

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