What does this LOINC code represent?

This LOINC code identifies a lab observation, measurement, question, or clinical concept in a standardized format.

Is this enough to understand my test result?

No. The code identifies the test or observation, but the interpretation depends on the actual result, reference range, and clinical context.

LOINCActiveObservation

LOINC Code 42204-8: Hairy cells/Leukocytes (BM)

Name: LOINC Code 42204-8: Hairy cells/Leukocytes (BM)
Creator: HealthAssure Clinical Team
Published: 2026-05-25T17:13:11.347Z

42204-8 is a LOINC code used to identify Hairy cells/Leukocytes (BM) in laboratory and clinical observation data. You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges. LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Hairy cells/Leukocytes. It is commonly used with the system or sample type Bone mar.

Reviewed by HealthAssure Clinical TeamUpdated 25 May 2026

What is this code?

LOINC codes identify tests, measurements, observations, survey items, and clinical questions in a standardized way. It is associated with the component Hairy cells/Leukocytes. It is commonly used with the system or sample type Bone mar.

When is it used?

Used in lab systems, EHRs, and clinical data exchange.
May identify a test, observation, survey item, or clinical document request rather than a diagnosis.
Status: ACTIVE
Order vs observation: Observation

What it does not mean

The code identifies the observation or test, not the actual result.

Key facts

Hairy cells/Leukocytes in Bone marrow
Hairy cells/Leukocytes
BM; BON; Bone marrow; Cell; Cellularity; Hairy cell leukaemia; HEMATOLOGY/CELL COUNTS; Leuc; Leuk; Leukocyte; Lkcs; MAR; Marrow (bone); minimal angle of resolution; Minimum angle of resolution; Number fraction; Percent; Point in time; QNT; Quan; Quant; Quantitative; Random; WBC; WBCs; White blood cell; White blood cells

Where you may see this code

You may see this code in lab systems, lab reports, EHR exports, interoperability feeds, or other structured clinical data exchanges.

Related SNOMED CT concepts

705114005SNOMED CT mapping for Hairy cells/Leukocytes (BM) (42204-8)

Related observations and tests

SNOMED_CT 705114005high

LOINC Code System

Source: LOINC-SNOMED cooperation package

Common synonyms

Hairy cells/Leukocytes (BM)Hairy cells/Leukocytes in Bone marrowHairy Cells NFr MarHairy cells/LeukocytesHEM/BCHairy cells/White Blood Cells, Bone marrowNFr

Frequently asked questions

Code details

Code42204-8

SystemLOINC

Display nameHairy cells/Leukocytes (BM)

DescriptionHairy cells/Leukocytes

Short nameHairy Cells NFr Mar

ComponentHairy cells/Leukocytes

PropertyNFr

TimingPt

System (specimen)Bone mar

ScaleQn

ClassHEM/BC

Example units%

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.16

Last changed2.79

Consumer names

Hairy cells/White Blood Cells, Bone marrow

Part names

Hairy cells/LeukocytesNFrPtBone marQnNumber FractionPoint in time (spot)Bone marrow

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from LOINC. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.