Understand guidelines to ensure accurate coding for neoplasms

Treatment site vs. metastatic site.

Signs and symptoms.

Sequencing guidelines.

Assigning codes for complex neoplasm cases can make anyone’s head spin.

Fortunately, many times you can alleviate complications related to coding for complex cases that involve neoplasms by simply focusing on critical guidelines and ensuring you understand the nuances for selecting the principal diagnosis and sequencing codes.

Malignancies and therapies

When the physician directs the treatment of a primary or secondary malignancy toward that primary or secondary malignancy, then that condition is the principal diagnosis unless the physician admits the patient solely for adjunctive therapy (e.g., chemotherapy, immunotherapy, or radiation therapy). In this case the therapy would be the principal diagnosis, said William E. Haik, MD, FCCP, director of DRG Review, Inc., in Fort Walton Beach, FL, during the HCPro, Inc. May 25 audio conference, “Principal Diagnosis for Complex Cases: Select the Right Code and Minimize Audit Risk.”

For example, a physician admits a patient for resection of colon cancer. A few days after surgery during the same admission the patient undergoes his or her first cycle of chemotherapy. In this case, the principal diagnosis is the colon cancer (code 153.9).

However, if a physician readmits a patient for chemotherapy two weeks after a mastectomy, chemotherapy (code V58.11) is the principal diagnosis, Haik explained.

Treatment of the primary site vs. the metastatic site

When the physician directs treatment toward the metastatic site, even though the primary site may still be present, assign the principal diagnosis based on the metastatic site. However, if the physician is still actively treating the primary site, report the primary site as an additional diagnosis, Haik said. If the primary site has been previously excised and is no longer under active treatment, then report a personal history of a neoplasm as an additional diagnosis.

“This has caused a lot of confusion for physicians as well,” Haik added.

Although not as common with today’s medications, Haik used the following clinical scenario to illustrate this coding guideline: A patient is admitted for a bilateral orchiectomy for bone metastasis from carcinoma of the prostate. The principal diagnosis is metastatic carcinoma to the bone (code 198.5). The additional diagnosis is carcinoma of the prostate (code 185).

Sometimes, however, documentation as to the primary site is lacking when there is a secondary site, said Jennifer Avery, CCS, CPC-H, CPC, CPC-I, senior regulatory specialist with HCPro, Inc., in Danvers, MA, who also spoke during the audio conference. Query the physician for additional documentation when clinical indicators suggest that a more specific code would be appropriate.

Signs and symptoms

When a patient presents with signs and symptoms related to a neoplasm, report the neoplasm or neoplasm-related pain as the principal diagnosis regardless of how many times the patient has been admitted to the hospital.

For a patient admitted with nausea and vomiting secondary to gastric carcinoma diagnosed during a previous admission, report the gastric carcinoma (code 151.9) as the principal diagnosis. However, consider a patient admitted with abdominal pain secondary to a previously diagnosed gastric carcinoma. After study, if the physician determines that no other acute condition is causing the abdominal pain, then report the neoplasm-related pain (code 338.3) as the principal diagnosis, Haik said.


Sequencing guidelines have become much more straightforward in the last year thanks in part to Coding Clinic, Second Quarter, 2010, p. 13. This Coding Clinic reinforced that when a patient is admitted due to a complication of either the malignancy or the treatment of the malignancy and the physician treats only the complication, then the complication is the principal diagnosis, Haik said. Previous Coding Clinic Q&A would have allowed the selection of the neoplasm as the principal diagnosis, he said.

For example, a patient with gross hematuria undergoes treatment for prostate carcinoma followed by subsequent bladder irrigation over the next 12 hours until the hematuria has ceased. For this clinical scenario, the principal diagnosis is gross hematuria (code 599.71). Report the prostate carcinoma (code 185) as an additional diagnosis, Haik explained.

There is one exception, however. Based on a directive in the fiscal year 2011 ICD-9-CM tabular index, coders should report a malignant neoplasm (if known) as the principal diagnosis even when the patient is admitted solely for the treatment for the malignant pleural effusion.

For example, a patient is admitted with a symptomatic malignant pleural effusion while undergoing chemotherapy for small cell carcinoma of the lung. The physician places a chest tube for pleural fluid drainage and a subsequent chemical pleurodesis with talc is instilled.

For this clinical scenario, due to the instructional note below code 511.81 for malignant pleural effusion, you would report the known small cell carcinoma of the lung (code 162.9) as the principal diagnosis and the malignant pleural effusion as an additional diagnosis.

Payment implications of ICD-10-CM

ICD-10-CM may have payment implications due to shifts in the MS-DRG based on the principal diagnosis assignment.

One such change results from an ICD-10-CM coding guideline for anemia associated with a malignancy. When an admission or encounter is for the management of an anemia associated with the malignancy, and the treatment is only for anemia, sequence the appropriate code for the malignancy as the principal or first-listed diagnosis followed by ICD-10-CM code D63.0 (Anemia in neoplastic disease).

“So this is the opposite of ICD-9-CM, and it will cause some shifts in the MS-DRGs,” Avery said.

For example, say if the patient’s underlying malignancy is breast carcinoma, and the patient was admitted with anemia. Under ICD-9-CM, the appropriate MS-DRG would be either:

  • 811 (Red blood cell disorders with an MCC), with a relative weight of 1.2544
  • 812 (Red blood cell disorders without an MCC), with a relative weight of 0.7957

However, under ICD-10-CM, the MS-DRG will vary based on the principal diagnosis of the type of malignancy. In this example with breast carcinoma, one of the following MS-DRGs would be appropriate:

  • 597 (Malignant breast disorders with an MCC), with a relative weight of 1.5596
  • 598 (Malignant breast disorders with a CC), with a relative weight of 1.0611
  • 599 (Malignant breast disorders without a CC/MCC), with a relative weight of 0.6265

“The ICD-10-CM balancing of the DRG relative weights should be equal to that of those in ICD-9-CM if taken as a whole, but you’re going to obviously have some winners and some losers with individual DRGs,” Haik said.

Coding Clinic guidance

To learn more about coding and sequencing guidelines for neoplasms, reference the following:

  • Coding Clinic for ICD-9-CM, Volume 2, Number 3, May–June 1985, pp. 12–14
  • Coding Clinic for ICD-9-CM, Volume 7, Number 1, Second Quarter 1990, pp. 7–11
  • Coding Clinic for ICD-9-CM, Second Quarter, 2010, p. 13
  • Coding Clinic for ICD-9-CM, Fourth Quarter, annually

Editor’s note: E-mail your questions to Managing Editor Doreen V. Bentley, CPC-A, at dbentley@hcpro.com. To learn more about coding for poisonings or adverse reactions or coding guidelines for diabetes, purchase a copy of HCPro, Inc.’s audio conference “Principal Diagnosis for Complex Cases: Select the Right Code and Minimize Audit Risk.”

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