This Editorial Guide is used for Education Purposes Only. It is used in the Authoring Courses and Certifications. It is based on the January 2026 Editorial Guide.

Centesis may be defined as the act of puncturing a body cavity or space with a hollow needle and drawing out fluid. Each centesis procedure involves both a puncture action and a needle aspiration action. It is correct to have two relationship groups for centesis procedures.

One group has a Method (attribute) of Puncture - action (qualifier value) and a Procedure site - Direct (attribute) of the structure being punctured.

A second group has a Method (attribute) of Aspiration - action (qualifier value) and a Procedure site - Indirect (attribute) of the space being aspirated.

• For example,

  • 91602002 |Thoracentesis (procedure)| has:

    • Role group 1:

      • Method = Puncture - action

This Editorial Guide is used for Education Purposes Only. It is used in the Authoring Courses and Certifications. It is based on the January 2026 Editorial Guide.

Aspiration is extraction using negative pressure. When modeling aspiration concepts, procedure site distinction is made if the removal is either (1) a substance from within a body structure or specific morphology, or (2) removal of any of the body structure itself (including cells).

1. Removing a substance from within a body structure or specific morphology should be modeled using Procedure site - Indirect (attribute) and/or Indirect morphology (attribute).

   1. For example,

      1. Paracentesis of skin (procedure) is removing a substance from within the body structure and not the body structure itself, it is modeled using Procedure site - Indirect (attribute) of Skin structure.

2. Removing body structure cells should be modeled with Procedure site - Direct (attribute) and/or Direct morphology (attribute).

   1. For example,

      1. Fine needle aspiration biopsy of skin (procedure) removes part of the body structure itself, and therefore is modeled using Procedure site - Direct (attribute) of Skin structure.

The nature of some aspirations means the procedure site will inherently be modeled as either direct or indirect regardless of whether the FSN states a substance is being removed.

• Example procedures using Procedure site - Direct (attribute):

  • Fine needle aspiration biopsy

  • Bone marrow aspiration

If the substance being aspirated is not stated in the FSN, do not model it, even if it might be implied.

• Exception: Aspiration of abscess can use Direct substance = Pus (substance).

  • Abscesses can be either septic (due to infection) or sterile (not due to infection). Most abscesses are septic; however, pus is characteristic of an abscess - whether septic or sterile. Model with Indirect morphology (attribute) of Abscess (morphologic abnormality) and the Direct substance (attribute) of Pus (substance). Pus does not have to be stated in the FSN.