ICD 10 Coding Alert

Diagnosis Deep Dive:

Be Prepared to Report Pleural Effusion

Published on Tue Oct 03, 2023

Hint: The Code first notes are crucial reading.

Patients may present to a pulmonologist or other provider with respiratory problems that arise from their pleura, the thin tissue surrounding the lungs and lining the chest cavity.

Navigating a provider’s documentation to assign and sequence ICD-10-CM codes correctly for pleural effusion is an important skillset. Consider these scenarios and expert tips to boost your ability to code this diagnosis.

Understand This Condition

Pleural effusion is a condition where fluid builds up in the area between the patient’s lungs and the chest wall, also known as the pleural space. The fluid buildup can cause breathing difficulties, chest pain, cough, fever and chills, hiccups, and rapid breathing.

The ICD-10-CM code set features three codes designated for pleural effusion diagnoses:

J90 (Pleural effusion, not elsewhere classified)
J91.0 (Malignant pleural effusion)
J91.8 (Pleural effusion in other conditions classified elsewhere)

Several medical conditions, such as pneumonia, heart failure, kidney disease, or cancer, can cause pleural effusion in patients.

Explore Malignant Pleural Effusion Coding

Code J91.0 is reserved to report a malignant pleural effusion (MPE) diagnosis. This is a condition where the provider determines that a malignancy, typically lung cancer or cancer that has metastasized to the lung, is causing the pleural effusion.

“MPE is an accumulation of cancer cells and fluid in the pleural space. The cancer, which is typically a lung cancer or another type of cancer that has spread to the pleural space, causes the increase in the pleural fluid,” says Carol Pohlig, BSN, RN, CPC, manager of coding and education in the department of medicine at the Hospital of the University of Pennsylvania in Philadelphia.

Code first: Before you assign J91.0 for an MPE diagnosis and move on with your day, you’ll want to take a pause. Code J91.0 features a Code first note instructing you to report the underlying neoplasm as the first-listed diagnosis.

Scenario: A patient is diagnosed with MPE caused by the malignant neoplasm of the right hilus. In this case, you’ll assign C34.01 (Malignant neoplasm of right main bronchus) as the first code and then J91.0 as the second code.

In this scenario, the provider determined the hilar neoplasm was causing the patient’s MPE, but can you report MPE if the patient is diagnosed with any cancer? No, because the MPE must be the result of a specific malignancy.

“Just because the patient has cancer and a pleural effusion at the same time, does not necessarily mean that the cancer is causing an MPE. While an MPE is likely for a patient with lung cancer, it isn’t likely for a patient who may have testicular cancer in situ but also has acute on chronic congestive heart failure (CHF). In that case, the heart failure is more likely causing the effusion,” Pohlig explains.

So, when coding MPE diagnoses, remember that documentation is your friend. If the provider diagnosed the patient with MPE in the medical record, look for information to support the diagnosis and what neoplasm is the underlying cause of the patient’s condition. However, a history of cancer doesn’t count when it comes to MPE. If a patient has a personal history of breast cancer, but isn’t actively receiving treatment for the cancer, then the pleural effusion wouldn’t be considered malignant.

Report the Underlying Condition First

Not all pleural effusions are caused by malignancies. Non-malignant pleural effusion can be a result of several cardiopulmonary conditions like CHF, pulmonary embolisms, and pneumonia.

In situations where the pulmonologist determines the cause of the patient’s pleural effusion, you’ll assign J91.8. While the cause of this pleural effusion won’t be cancer, you’ll use the same logic to report the condition. “Code J91.8 should be used for the non-malignant effusion, but the cause of the effusion must also be reported since this is a manifestation code,” Pohlig says. The underlying cause of J91.8 should be a respiratory illness.

As a helpful reminder, the ICD-10-CM code set places a Code first note under J91.8 instructing you to assign a code for the underlying disease before J91.8.

Scenario: The provider diagnoses a patient with pleural effusion caused by pneumonia due to Methicillin resistant Staphylococcus aureus (MRSA). You’ll assign J15.212 (Pneumonia due to Methicillin resistant Staphylococcus aureus) first, followed by J91.8 to report the patient’s diagnosis.

You may also encounter cases where the provider determines the patient’s pleural effusion is caused by non-respiratory conditions such as CHF or systemic lupus erythematosus (SLE). In those cases, you’ll refer to the Excludes2 note listed under parent code J91.- (Pleural effusion in conditions classified elsewhere).

Typically, an Excludes2 note under the parent code indicates that the two conditions can be coded together. The Excludes2 note listed under J91.- allows you to report the pleural effusion and the non-respiratory condition together. “If the source causing the pleural effusion is non-respiratory, such as CHF or SLE, you would report this condition with the appropriate code listed within the corresponding code family,” Pohlig says.

However, the Excludes2 listed condition may adequately represent the condition and you will only need to report one code.

For instance, if the patient’s SLE is causing the patient’s pleural effusion, you’ll assign M32.13 (Lung involvement in systemic lupus erythematosus) since M32.13 also features “Pleural effusion due to systemic lupus erythematosus” as an additional descriptor.

Rely on J90 for Pleural Effusion NOS

Code J90 is reserved for cases where your provider may use other terms in their documentation to indicate a pleural effusion diagnosis of an undetermined origin.

These terms are listed under J90 as synonyms:

Encysted pleurisy
Pleural effusion not otherwise specified (NOS)
Pleurisy with effusion (exudative) (serous)

Code J90 features an Excludes1 note that prevents you from reporting the following conditions with J90 since the conditions listed below can’t exist with J90:

A15.6 (Tuberculous pleurisy)
R09.1 (Pleurisy)
J94.0 (Chylous effusion)
J91.0 (Pleural effusion in conditions classified elsewhere)

Listen to Your Gut

Regardless of whether you’ve been coding for years or are newly certified, you’ll set yourself up for coding success by carefully reviewing ICD-10-CM instructional notes and your provider’s documentation. And, like always, query the provider if you’re unsure of the pleural effusion’s underlying condition.