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 40521-7: Monocytes/Leukocytes Manual cnt (Pleur fld)

Name: LOINC Code 40521-7: Monocytes/Leukocytes Manual cnt (Pleur fld)
Creator: HealthAssure Clinical Team
Published: 2026-05-25T17:13:11.347Z

40521-7 is a LOINC code used to identify Monocytes/Leukocytes Manual cnt (Pleur fld) 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 Monocytes/Leukocytes. It is commonly used with the system or sample type Plr fld.

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 Monocytes/Leukocytes. It is commonly used with the system or sample type Plr fld.

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
Method: Manual count

What it does not mean

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

Key facts

Monocytes/Leukocytes in Pleural fluid by Manual count
Monocytes/Leukocytes
HEMATOLOGY/CELL COUNTS; Leuc; Leuk; Leukocyte; Lkcs; Manl; Mono; Monocyte; Monos; Number fraction; Percent; Pleural; Pleural fluid; Point in time; QNT; Quan; Quant; Quantitative; Random; thoracentesis fluid; 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 Monocytes/Leukocytes Manual cnt (Pleur fld) (40521-7)

Related observations and tests

SNOMED_CT 705114005high

LOINC Code System

Source: LOINC-SNOMED cooperation package

Common synonyms

Monocytes/Leukocytes Manual cnt (Pleur fld)Monocytes/Leukocytes in Pleural fluid by Manual countMonocytes NFr Plr ManualMonocytes/LeukocytesHEM/BCMonocytes/White Blood Cells, Pleural fluidNFr

Frequently asked questions

Code details

Code40521-7

SystemLOINC

Display nameMonocytes/Leukocytes Manual cnt (Pleur fld)

DescriptionMonocytes/Leukocytes

Short nameMonocytes NFr Plr Manual

ComponentMonocytes/Leukocytes

PropertyNFr

TimingPt

System (specimen)Plr fld

ScaleQn

MethodManual count

ClassHEM/BC

Example units%

StatusACTIVE

Order/ObservationObservation

Flags

BillableNo

Valid clinical useNo

Source

SourceLOINC

Version2.82

Releasemain

First released2.15

Last changed2.79

Consumer names

Monocytes/White Blood Cells, Pleural fluid

Part names

Monocytes/leukocytesNFrPtPlr fldQnManual countNumber FractionPoint in time (spot)Pleural fluid

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.