Pathology/Lab Coding Alert

Master hyperplasia terminology.

Pathology cases involving uterine endometrium can hold many pitfalls for coders — both on the ICD-10-CM and CPT® sides of the equation.

Study the following example, then test your hand at coding the case, and compare your choices to our experts’ decisions.

Endometrial Sampling Case

An ob-gyn submits two uterine tissue samples from a 54-year-old woman with the following information:

Submitting Dx:

• Patient presents with menometrorrhagia. Endometrial thickening observed on ultrasound; rule out endometrial cancer
• Clinical data:
  ​o History of breast cancer
  o Estrogen receptor positive (ER+)
  o Taking Tamoxifen to reduce breast cancer risk
  o BMI 33.3

Submitted specimens from hysteroscopy dilation and curettage:

• EMC specimen: 2.8 cm curettage sampling of uterine mucous membrane
• ECC specimen: 1.4 cm curettage sampling of mucous membrane of cervical lining

Pathology Findings:

• EMC specimen: Grossly increased endometrial volume beyond normal cycling endometrium Processed 2 cassettes from 4.2 mm lesion: Microscopic findings: gland: stroma ratio 2:1, branching glands with nuclear enlargement, chromatin coarsening, loss of polarity – atypical hyperplasia
• ECC specimen: gland: stroma ratio 1.5:1, no cytologic atypia

Decide what ICD-10-CM and CPT^® codes you would assign, and then read on to see how you did.

Look for Procedure Codes

The ob-gyn separately identifies and submits two hysteroscopy specimens, which the pathologist separately examines and diagnoses.

“You should report a separate code for each individual specimen,” says R.M. Stainton Jr., MD, president of Doctors’ Anatomic Pathology Services in Jonesboro, Ark.

Decode acronyms: The listed specimens are EMC, which is tissue from an endometrial curettage, and ECC, which is tissue from endocervical curettage. “The EMC and ECC are biopsy specimens,” Stainton says.

You should report the specimens using the following codes:

• For the EMC specimen, list 88305 (Level IV - Surgical pathology, gross and microscopic examination… Endometrium, curettings/biopsy…).
• For the ECC specimen, report an additional unit of 88305 (… Endocervix, curettings/biopsy…).

Depending on the payer, you may report 88305 x 2 on one claim line, or you may need to list the procedures on two claim lines.

Focus Final Diagnosis

The ob-gyn performed the hysteroscopy to rule out endometrial cancer based on menometrorrhagia (N92.1, Excessive and frequent menstruation with irregular cycle) and ultrasound findings of endometrial thickening. You’ll find the ICD-10-CM code for that under “thickened endometrium” in the alphabetic index, which will lead you to R93.8-, says Judy Klobutcher, BSN, MBA, CPC, coding specialist at nThrive in Ashland, Ohio. Adding the fifth character, “9” leads to “Abnormal findings on diagnostic imaging of other body structures,” which would include the uterus.

Hold it: If you list R93.89 and N92.1 as the diagnosis for this case, you would be wrong. Because you’re coding for the pathologist, you need to report the final diagnosis based on the pathology findings, not based on the ob-gyn’s ultrasound findings or listed symptoms that were the reason for the test.

Do this: Report the “atypical hyperplasia” finding using N85.02 (Endometrial intraepithelial neoplasia (EIN)). The ICD-10-CM note under N85.02 includes “with atypia” as an example of EIN.

ICD-10-CM recognizes a two-level endometrial classification — N85.01 (Benign endometrial hyperplasia), which is without atypia, or N85.02.

“The two levels distinguish benign hormonal effects of unopposed estrogens, described by N85.01, versus emergent pre-cancerous lesions, described by N85.02,” explains Melanie Witt, RN, CPC, MA, an independent coding expert based in Guadalupita, New Mexico, Clinical significance: The difference between those two types of endometrial hyperplasia suggests different prognosis and treatment options. Benign hyperplasia may respond well to progestins, but EIN may suggest the need for hysterectomy due to high rate of concurrent or conversion to endometrial cancer.

ICD-10’s EIN and benign hyperplasia parallel the World Health Organization (WHO) 2014 classification for endometrial hyperplasia.

Problem: Earlier WHO 94 and ICD-9 classified endometrial hyperplasia into four groups based on glandular “architectural” complexity (simple or complex) and nuclear atypia (non-atypical or atypical), and pathologists might still use that nomenclature, or descriptors such as “mild,” “severe,” “cystic,” or “glandular” to describe endometrial hyperplasia.

Solution: If the pathology report uses the older type of descriptors, look at the “includes” notes in ICD-10-CM for direction. For instance, a note under N85.01 states that the code includes “without atypia,” or “without complex atypia,” or “without simple atypia.” If the pathology report uses other descriptors that do not clearly translate to benign hyperplasia or EIN/atypical hyperplasia, you should turn to N85.00 (Endometrial hyperplasia, unspecified). Notes under N85.00 include adenomatous, benign, cystic, glandular, glandular-cystic, polypoid, and hyperplastic endometritis.

Code Comorbid Conditions

Although you don’t need to report the signs and symptoms that led to the biopsy findings of atypical hyperplasia (EIN), it is valuable to note the comorbid conditions that might impact treatment choices.

Risk factors for developing endometrial cancer include obesity, tamoxifen treatment, and ER+ status, among others, so a complete report will account for those relevant conditions that the ob-gyn initially listed.

Signify estrogen: Because unopposed estrogen can impact endometrial cancer, you should include information provided by the ob-gyn, such as the patient’s ER+ status (Z17.0 (Estrogen receptor positive status (ER+)), which is a genetic condition that warrants also listing Z15.04 (Genetic susceptibility to malignant neoplasm of endometrium). Because Tamoxifen is an estrogen antagonist, you should also note the medication using Z79.810 (Long term [current] use of selective estrogen receptor modulators (SERMs)).