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.
Observable entity concepts representing histopathology examination observables of neoplasms are being modeled according to a series of templates.
Please see the templates listed here: Observable entity templates See the Cancer Synoptic Reporting area for more information about the project.
Concepts containing a primary malignant neoplasm from the observable entity subhierarchy employ the 704321009 |Characterizes (attribute)| with the target qualifier value of 1234914003 |Malignant proliferation of primary neoplasm (qualifier value)| in order to define primary (which matches the target value of the Pathological process (attribute) used by concepts in the Disorder hierarchy).
For example,
1136681000004107 |Anatomic location of excised primary malignant neoplasm (observable entity)| applies the Characterizes (attribute) with a target of Malignant proliferation of primary neoplasm (qualifier value).
Stated view of 1136681000004107 |Anatomic location of excised primary malignant neoplasm (observable entity)|:
Stated view of 372087000 |Primary malignant neoplasm (disorder)|:
Concepts containing a metastatic malignant neoplasm from the observable entity subhierarchy do not use 704321009 |Characterizes (attribute)|, but instead are defined by the specific metastatic morphologic abnormality. For example, 444384007 |Number of regional lymph nodes containing metastatic neoplasm in excised specimen (observable entity)| has the attribute 246093002 |Component (attribute)| with a target value of 14799000 |Neoplasm, metastatic (morphologic abnormality)|.
Concepts containing a metastatic malignant neoplasm from the observable entity subhierarchy do not use 704321009 |Characterizes (attribute)|, but instead are defined by the specific metastatic morphologic abnormality. For example, 444384007 |Number of regional lymph nodes containing metastatic neoplasm in excised specimen (observable entity)| has the attribute 246093002 |Component (attribute)| with a target value of 14799000 |Neoplasm, metastatic (morphologic abnormality)|.
Concepts containing a metastatic malignant neoplasm from the observable entity subhierarchy do not use 704321009 |Characterizes (attribute)|, but instead are defined by the specific metastatic morphologic abnormality. For example, 444384007 |Number of regional lymph nodes containing metastatic neoplasm in excised specimen (observable entity)| has the attribute 246093002 |Component (attribute)| with a target value of 14799000 |Neoplasm, metastatic (morphologic abnormality)|.
Colorectum
The terms colorectal and colorectum, commonly used by pathologists, are included in descriptions for concepts referring to neoplasms modeled with 1285733009 |Structure of cecum and/or colon and/or rectum (body structure)|. 1285733009 |Structure of cecum and/or colon and/or rectum (body structure)| is needed because neoplasms are the same from the cecum to rectum and are considered as a group in cancer synoptic reporting protocols. Note, there is no consensus concerning the definition of colon in the literature and between different domains.
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.
Nomenclature, Properties, and Units (NPU) is a coding system and terminology for identification and communication of examination results from clinical laboratories. Please see their website for more information: .
Logically there is a relationship between NPU and SNOMED CT observable entities. A pilot project examined overlaps and possible alignment; further work may be done. However, there is no formally maintained SNOMED CT documentation on this alignment.
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.
Naming conventions for estimated and measured intake or nutrient administration, in aggregate or as a portion of intake via a specified route (ie, oral, gastroenteral [enteral nutrition], parenteral nutrition, and via intravenous fluids), is as follows:
FSN: [technique] quantity of intake of [substance] via [route] in [timeframe] (observable entity)
SYN: [technique] quantity of intake of [substance] via [route] in [timeframe]
See the specific template: A nutritional intake (observable entity) - v1.0.
For example,
789106008 | Estimated quantity of intake of phosphorous in 24 hours (observable entity)|
FSN: Estimated quantity of intake of phosphorous in 24 hours (observable entity)
PT: Estimated quantity of intake of phosphorous in 24 hours
Dietary
"Dietary" is considered ambiguous and should not be included in SNOMED CT. Existing content that includes "dietary" will be considered for inactivation.
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.
The Property (qualifier value) hierarchy contains the following:
118538004 |Mass, a measure of quantity of matter (property) (qualifier value)|
726527001 |Weight (property) (qualifier value)|
Very rarely is the physics definition of weight used. When the term weight is used, it is most often referring to mass , as further demonstrated by the units of measure i.e., grams, kilograms, etc. Unless units specific to the physics definition of weight are specified using Newtons, assume that mass is implied.
To summarize, always use the mass qualifier value unless a concept is requested with Newton units that specifically refer to weight.
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.
When observable entity concepts have been given a value, they behave like clinical findings, with respect to the concept model for context.
When observable entity concepts have not been given a value, they behave like procedures, with respect to the concept model for context.
The observable entity model has been implemented in limited content areas in SNOMED CT thus far. Most of the content in the hierarchy is primitive.
Over 165 observable entity concepts have been modeled describing physiological measurements (body temperature, respiratory rate, heart rate, blood pressure). Most of these are sufficiently defined using the attributes. |Vital sign (observable entity)| has been inactivated since it could not be universally defined.
Additional concepts using observable entity attributes have been defined since the January 2020 release. The majority of the changes are related to nutritional intake (e.g., food intake, vitamin intake, fasting pattern) observable entity concepts.
Susceptibility observables should be modeled in accordance with the specified templates.
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.
Templates are available for modeling quality observables and for process observables:
The Susceptibility template is a disposition observable; there is no simple template at this time.
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.
Core body temperature is the temperature in the deep tissues and internal organs, including the brain. The gold standard site for measuring core body temperature is the pulmonary artery. Other sites for measuring core body temperature include the nasopharynx, esophagus, bladder, gastrointestinal tract, and vagina. Some peripheral sites are commonly used to estimate core body temperature but are not a true representation of core body temperature on their own, e.g., axillary region, inguinal region, sublingual space. Body surface temperature is measured at several sites, e.g., skin, foot, spine.
For example,
698831002 |Core body temperature measured in nasopharynx (observable entity)|
415882003 |Estimated core body temperature measured in axillary region (observable entity)|
364518005 |Temperature of foot (observable entity)|
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.
When microbiology laboratory results are encoded, it is important to be aware of the context provided by the observation, i.e. the test performed and, therefore, the implied meaning of the result value, i.e. the organism.
For example, the combination of Logical Observation Identifiers Names and Codes (LOINC) for the lab test and SNOMED CT for the organism, provides a unique and specific meaning:
LOINC provides microbiology reporting codes with attributes including the property through the use of PRID(presence or identity) and the scale through the use of NOM (nominal or categorical response that does not have a natural ordering) as the result value (typically the name of organism).
Use of organism concepts in combination with such LOINC codes implies that a specific organism is seen, detected, identified, isolated, or present.
Use organism X or organism Y when a laboratory report indicates a single isolate is assumed, but the lab is unable (for any reason) to differentiate the result instance.
For example,
703015006 | Human coxsackievirus or human echovirus (finding)|
Use organism X, not organism Y when a laboratory report indicates a class of organisms described by the exclusion of specific Linnaean or non-Linnaean classes. These concepts are found in the organism hierarchy (based on reasonable use cases to avoid a combinatorial explosion). They are a primitive super class, in between the species or species subtype.
For example,
115407004 | Haemophilus influenzae, not b (organism)|
Exception
The common term yeast can refer to two separate classes: 1) a morphologic form of a dimorphic fungus; or 2) an organism in kingdom Fungi that is truly a yeast. Therefore, while the super class yeast is represented as an organism, “X, not organism Y” type concept is represented in the clinical finding hierarchy (as descendant of 769070007 |Yeast detected (finding)|) since one potential meaning of use is a diagnostic morphologic form of an organism rather than an organism itself.
For example,
769071006 | Yeast not Candida albicans detected (finding)|
Use Genus X, not species Y and not species Z when a laboratory report indicates a species of Genus X and confirms that it is not species Y, nor species Z. E.g. Bacillus species, not Bacillus anthracis and not Bacillus cereus (organism).
Use this naming convention only with Genus, species, and subspecies levels of the hierarchy.
Laboratory reports and journal articles may include an organism that could not be serotyped, e.g. E. coli, untypable. The requests for such concepts are declined due to ambiguity. Instead, use the closest taxonomic level in the hierarchy.
Laboratory findings may be reported with a status of preliminary, presumptive, provisional, etc. These typically cover reportable or notifiable lab values. The status of a report is different from the result; it is part of the electronic health application model/message. The requests for such concepts are declined as they are ambiguous and subject to limitless combinations.
Some laboratories report findings indicating a mixed population of bacteria from several classes, e.g. mixed anaerobic Gram negative bacilli. The request for such a concept is added as a clinical finding. The actual organism is unknown, however there is a result, although more general.
Laboratories perform and report on specific tests to identify the absence, as well as the presence, of a particular pathogenic organism. Laboratories typically report negative result values, such as X not seen , X not detected , X not isolated , and no X seen (or identified or isolated) and positive results as X seen , X detected , and X isolated. The following tables includes the acceptable modeling for negative and positive results.
Microbiology Tests: Reporting of Negative and Positive Values with Examples
Lab test type (Observation)
Result value
Example lab test (e.g. SNOMED CT and/or LOINC term)
Example result value
General culture (where implied scale = nominal)
No X isolated (finding)
X (organism)
61594008 |Microbial culture (procedure)|
11475-1 |Microorganism identified in Unspecified specimen by Culture
Valid value
168204005|Salmonella not isolated (finding)|
27268008|Genus Salmonella (organism)|
Invalid value
264887000 |Not isolated (qualifier value)
| 46651001 |Isolated (qualifier value)|
Organism
On its own, an organism concept can only indicate the definition of that organism. Its detection or presence can only be implied when it is paired with other information that may come from the electronic health application and/or from the LOINC observation.
Concepts with presumptive values
Existing concepts with presumptive values are undergoing review for inactivation.
Organism Specific culture
Not isolated (qualifier value) Isolated (qualifier value)
122206002 |Bordetella pertussis culture (procedure)|
48741-3 |Bordetella pertussis; Nasopharynx; Culture
Valid value
264887000|Not isolated (qualifier value)| 46651001|Isolated (qualifier value)|
Invalid value
Bordetella pertussis not isolated Bordetella pertussis isolated
General microscopic testing (where implied scale = Nominal)
No X seen (finding)
X (organism)
609009000 |Microscopic examination of bacterial smear of urine specimen (procedure)|
25145-4 |Bacteria [Presence] in Urine sediment by Light microscopy
Valid value
27268008|Genus Salmonella (organism)|
Invalid value
47492008 |Not seen (qualifier value)|
Specific microscopic testing
Not seen (qualifier value) Present (qualifier value)
408215009 |Cryptosporidium microscopy (procedure)|
Valid value
47492008|Not seen (qualifier value)| 52101004|Present (qualifier value)|
Invalid value
No Cryptosporidium seen Cryptosporidium seen
Serologic, DNA or other organism specific test
Not detected (qualifier value) Detected (qualifier value)
Rationale: Almost all of these tests are organism-specific
871555000 |Detection of ribonucleic acid of Severe acute respiratory syndrome coronavirus 2 (observable entity)|
95406-5 |SARS-CoV-2 (COVID-19) RNA [Presence] in Nose by NAA with probe detection
Valid value
260415000|Not detected (qualifier value)|
260373001|Detected (qualifier value)|
Invalid value
No Severe acute respiratory syndrome coronavirus 2 detected
Severe acute respiratory syndrome coronavirus 2 detected
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.
Logical Observation Identifiers Names and Codes (LOINC) terms are defined using the Observable Entity model in SNOMED CT as produced in the LOINC - SNOMED CT Cooperation Project releases.
The project release documentation contains information about how LOINC terms and parts are aligned with SNOMED CT concepts using the model.
For more information please see .