Malignancy comes first when coding anemia caused by a neoplasm in ICD-10-CM.

When anemia shows up in a patient who also has cancer, which code leads the chart? This is one of those sequencing questions that’s surprisingly practical, even if you don’t want to think of it as an “exam thing.” It’s about capturing the true clinical story so the chart communicates what’s driving the patient’s condition and what needs attention first.

Let me explain the core idea in plain terms. Anemia can be a result of many things—iron deficiency, chronic disease, kidney issues, pregnancy, you name it. When the anemia is caused by a neoplasm (a malignant growth), the cancer is the root problem. The anemia is a downstream effect. In ICD-10-CM, the guideline-thinking favors the underlying condition that sets the whole scenario in motion. So, the malignancy should be listed first, and the anemia coded as a secondary condition.

Here’s the question you posed, in a nutshell:

In anemia due to a neoplasm, which code is listed first?

• A. Anemia

• B. Malignancy

• C. Neoplasm

• D. Organ failure

The correct answer is B, Malignancy. Why? Because the underlying malignancy is the primary diagnosis that explains the patient’s anemia. The cancer provides the clinical context—the engine behind the symptoms. Sequencing it first isn’t just a rule slapped on a worksheet; it’s about truth-telling in a medical record. The intent behind ICD-10-CM guidelines is to reflect the patient’s main issue and the chain of events that follow from it. By prioritizing the malignancy, the chart becomes a faithful map of the care path: treat the cancer, monitor how the anemia evolves as a consequence, and track outcomes accordingly.

Let’s unpack the logic a bit more, so the approach isn’t a mere memorized line but a robust habit you can apply in real life. The guidelines distinguish between what’s the primary problem and what’s a complication or manifestation. When a single disease (the cancer) explains another problem (the anemia), you sequence the root cause first. The anemia then becomes a secondary diagnosis that captures the adverse effect or clinical consequence. This sequencing mirrors how clinicians think in practice: you diagnose the main disease, then document what emerges because of it.

A practical way to internalize this goes like this:

• Step 1: Identify the root cause. Is there a disease that clearly drives the patient’s current problems? In our case, the cancer is the driver.

• Step 2: Identify the complication or manifestation. What condition is directly caused by the root cause? Here, anemia is the consequence.

• Step 3: Sequence the root cause first. Put the malignancy code at the top of the list.

• Step 4: Add the complication next. Document the anemia as a separate, second code.

• Step 5: Review for any additional context. Are there organ-specific details, metastasis, or treatment-induced factors that could refine the coding? If yes, layer those in after the two primary codes.

This approach isn’t limited to a single scenario. It’s a pattern you’ll see again and again: underlying disease first, then the downstream effects, unless the clinical record clearly shows a different priority. It’s all about giving the right weight to the main condition so the data reflect what actually needs attention in treatment planning, research, and resource allocation.

A few practical examples can help solidify the concept:

• If a patient has a malignant tumor and develops anemia due to chronic disease, the tumor diagnosis comes first, followed by anemia.

• If a patient has a neoplasm and anemia from bone marrow suppression after chemotherapy, the cancer code still goes first, with the hematologic finding documented afterward to capture the downstream impact.

• If multiple issues are present, such as organ failure, you’d consider which condition is driving the current clinical picture. The same sequencing logic applies: primary disease first, then secondary manifestations.

Common missteps are worth watching for, because that’s where miscommunication tends to creep in. A frequent trap is to “name the symptom” first—in this case, coding the anemia ahead of the cancer. That can obscure the patient’s actual clinical trajectory and muddle data used for care gaps, outcomes, and even billing. Another pitfall is treating the anemia as an independent primary problem when the guidelines clearly tie it to the malignancy. In those moments, a quick reminder helps: the chart should tell the story of what’s driving what, with the root cause leading the narrative.

From a documentation standpoint, this sequencing has tangible effects beyond billing. It affects how teams interpret the patient’s prognosis, how treatment plans are shaped, and how data analysts track cancer-related complications across populations. If the underlying disease isn’t clearly identified and prioritized, the data can misrepresent the patient journey—masking urgent needs or skewing epidemiological insights. In short, the order matters because it anchors both clinical decisions and data-driven improvements.

Let me connect this to something you might hear on the floor, in a chart review, or when a coder-and-clinician conversation happens: “What’s driving the patient’s current condition?” The answer often points to the root cause. In our anemia-with-cancer example, the driving force is the malignancy. The anemia is the ripple. When you code it that way, you help ensure the chart remains faithful to the actual clinical sequence.

If you’re building fluency in ICD-10-CM sequencing, think of it as two layers of a story:

• Layer 1: The main plot—the underlying malignancy that sets the stage.

• Layer 2: The subplot—the anemia that arises as a consequence of that stage.

When both layers are present, you tell the truth of the patient’s medical narrative by listing the malignancy first and then the anemia. It’s a small textual choice with meaningful downstream impact—on patient care, documentation clarity, and the integrity of health data.

To summarize, in anemia caused by a neoplasm, the malignancy is listed first. It’s the primary diagnosis that provides the essential context for the anemia, which is its secondary manifestation. This sequencing approach aligns with ICD-10-CM guidelines and helps ensure that the medical record reflects the patient’s clinical reality as it unfolds.

If you’re curious to deepen your understanding, you’ll find that the same principle applies across many scenarios: identify the root disease driving the clinical picture, then document the complications or manifestations that flow from it. The skill isn’t just about choosing a code in isolation—it’s about telling a clear, accurate story in the medical record. And when you get that right, you’re not just coding—you’re supporting better care decisions and meaningful data.

A quick recap for retention:

• The correct choice for anemia due to neoplasm is Malignancy (the underlying cancer).

• The cancer goes first because it represents the clinical context and driver of the anemia.

• The anemia is coded as a secondary condition, capturing the downstream effect.

• Always check for additional details that could refine the coding, but keep the root cause as the lead.

If you’d like, I can walk you through more scenarios that hinge on sequencing the underlying condition versus its complications. It’s a handy skill, and when you see it in action, the logic becomes almost intuitive. And yes, getting comfortable with this can make a real difference—not just on paper, but in the care teams’ everyday decisions and the bigger picture of health data quality.