Oncology & Hematology Coding Alert

Remember to keep these ovarian cyst codes handy, too.

On the surface, coding for malignant ovarian neoplasms is as easy as choosing one code from C56.- (Malignant neoplasm of ovary). All you have to do is verify the laterality of the cancer; add a 4th digit for right (1), left (2), bilateral (3), or unspecified (9); and you’re done, right?

If it was only that easy. Unfortunately, there’s a lot more to ovarian cancer coding than you might think. So, here are six important things you should remember every time you code for the condition.

1. Know What ‘Functional Activity’ Means

The C56.- codes all carry a “use additional code” instruction that asks you to use an additional code for any functional activity. In neoplasm coding, that means using an additional code from ICD-10-CM chapter 4, Endocrine, Nutritional, and Metabolic Diseases, says Stephanie A. Thebarge, CPC, CPCO, CPMA, CPPM, CPB, CEMC, CHONC, compliance manager at New England Cancer Specialists in Scarborough, Maine.

“If there are documented metabolic issues associated with a malignant neoplasm, separate codes from chapter 4 may be used to describe these metabolic conditions, but they would be coded independently of the neoplasm. That’s why it says, ‘use additional code to identify any functional activity.’ These codes help identify any metabolic issues documented on pathology; they are to be reported separately,” Thebarge notes.

For ovarian tumors, that means adding codes that document the influence their hormonal activity has on other body functions such as menstrual cycles, ovulation, and reproduction. So, you will add codes, when appropriate, for conditions such as:

• E25.8 (Other adrenogenital disorders)
• E28.0 (Estrogen excess)
• E28.1 (Androgen excess)
• E28.8 (Other ovarian dysfunction)
• E30.1 (Precocious puberty)

2. Know How to Code for Metastatic Ovarian Cancer

The secondary codes for metastatic ovarian cancer are a little tricky to apply, simply because, unlike the primary malignant ovarian cancer codes, you’ll use 5th digit 0 if the affected ovary is not specified instead of 4th digit 9:

• C79.60 (Secondary malignant neoplasm of unspecified ovary)
• C79.61 (… right ovary)
• C79.62 (… left ovary)
• C79.63 (… bilateral ovaries)

Code this: Your oncologist diagnoses a patient with colorectal adenocarcinoma with metastatic bilateral ovarian cancer. You’ll use a code such as C18.9 (Malignant neoplasm of colon, unspecified) for the primary cancer with C79.63 for the metastatic ovarian cancer.

3. Know How to Code for Uncertain Behavior

Again, assigning an uncertain behavior code is tricky for two reasons: First, you must remember to obey the same additional code instruction as the C56.- codes to report functional activity, and second, you will have to use two codes, D39.11 (Neoplasm of uncertain behavior of right ovary) and D39.12 (Neoplasm of uncertain behavior of left ovary), to document bilaterality as there is no bilateral code in the D39.- category. To report an unspecified ovary, the appropriate choice is D39.10 (Neoplasm of uncertain behavior of unspecified ovary).

4. Know the Difference Between Benign Ovarian Neoplasm and Ovarian Cyst Codes

Ovarian tumors and ovarian cysts present with similar signs and symptoms, such as “abdominal pain, bloating, pain with intercourse, menstrual irregularities and, more rarely, frequent urination” (https://ocrahope.org/news/science-made-simple-ovarian-cysts-and-ovarian-cancer/). So, you’ll want to keep the following codes handy.

If, on precise identification of an ovarian tumor, the oncologist decides it is benign, you will go with one or more of the following:

• D27.0 (Benign neoplasm of right ovary)
• D27.1 (… left ovary)
• D27.9 (… unspecified ovary)

Like the uncertain behavior codes, there is no bilateral benign neoplasm code. And the D27.- codes also have the use additional code for any functional activity instruction.

But you’ll have to go outside the neoplasm codes to Chapter 14: Diseases of Genitourinary System to locate appropriate ovarian cyst codes. You’ll find most of them among the N83.- (Noninflammatory disorders of ovary, fallopian tube and broad ligament) group:

• N83.0- (Follicular cyst of ovary)
• N83.1 - (Corpus luteum cyst)
• N83.20- (Unspecified ovarian cysts)
• N83.29- (Other ovarian cysts)

You might also use N80.1- (Endometriosis of ovary) if the final diagnosis is an ovarian endometrioma, which is filled with dark brown endometrial fluid, leading to the synonym “chocolate cyst,” which some sources use.

5. Pay Attention to the Excludes Notes

Unsurprisingly, as benign ovarian tumors and ovarian cysts exhibit similar characteristics, they are subject to several Excludes1 and Excludes2 instructions.

N83.2-, for example, contains an Excludes1 note indicating that an ovarian cyst documented as neoplastic should instead be coded to D27.- as the two conditions cannot occur at the same time. However, per ICD-10-CM guideline I.A.12.a, if the two conditions are unrelated, such as a neoplastic cyst of the left ovary and an unspecified cyst of the right ovary, both codes could be reported if appropriately documented. But the D27.- codes have an Excludes2 instruction allowing you to code a benign ovarian neoplasm with numerous ovarian cyst codes, including specific conditions coded to N80.1-, N83.0-, N83.1-, and N83.2-.

6. Know When to Code for Personal History

As with all cancers, “when a primary malignancy has been previously excised or eradicated from its site and, there is no further treatment directed at that site and there is no evidence of any existing primary malignancy,” per ICD-10-CM guideline I.C.2.d, you’ll use Z85.43 (Personal history of malignant neoplasm of ovary).

Remember: Only the clinician can make the determination for the criteria outlined in the guideline to determine whether the malignancy is active or should be coded as personal history as supported in their documentation. When documentation is not clear, query the physician and ask for clarification of the status be documented so you can assign an accurate code.