Find clear information on Mismatch Repair MMR testing, including clinical significance, medical coding guidelines, and documentation requirements for healthcare professionals. Learn about the role of MMR deficiency in Lynch syndrome diagnosis and appropriate CPT codes for IHC and PCR based MMR testing. Understand the importance of accurate pathology reports and molecular diagnostics for effective cancer risk assessment and personalized treatment planning. Explore resources for genetic counseling and hereditary cancer screening related to Mismatch Repair gene mutations.
Also known as
Encounter for screening for other
Encounter for screening for genetic susceptibility to cancer.
Family history of malignant neoplasm
Family history of malignant neoplasm of digestive organs.
Family history of malignant neoplasm
Family history of malignant neoplasm of ill-defined sites.
Follow this step-by-step guide to choose the correct ICD-10 code.
Is testing for diagnostic confirmation?
When to use each related code
| Description |
|---|
| Mismatch Repair Testing |
| Lynch Syndrome |
| Constitutional Mismatch Repair Deficiency |
Q: When should I order mismatch repair protein immunohistochemistry (MMR IHC) testing and microsatellite instability (MSI) testing for suspected Lynch syndrome in colorectal cancer patients?
A: Mismatch repair protein immunohistochemistry (MMR IHC) testing and microsatellite instability (MSI) testing are essential for identifying patients with Lynch syndrome, a hereditary cancer predisposition syndrome increasing the risk of colorectal and other cancers. Current guidelines recommend universal MMR/MSI testing for all newly diagnosed colorectal cancers, regardless of age or family history. This approach maximizes the detection of Lynch syndrome cases, as a significant proportion are not readily identified through family history alone. Alternatively, a two-tiered approach can be used, starting with either IHC or MSI testing. If abnormalities are detected, the second test is then performed. Consider implementing universal MMR/MSI testing in your practice to enhance Lynch syndrome detection and facilitate appropriate surveillance and management strategies for patients and their families. Explore how genetic counseling can further benefit patients with suspected Lynch syndrome.
Q: What are the different methods for assessing mismatch repair deficiency (dMMR) in endometrial cancer, and what are the clinical implications of the results?
A: Mismatch repair deficiency (dMMR) testing in endometrial cancer can be performed using several methods, including immunohistochemistry (IHC) which assesses the expression of MMR proteins (MLH1, MSH2, MSH6, and PMS2), and polymerase chain reaction (PCR)-based microsatellite instability (MSI) testing which analyzes specific DNA regions for instability. Both methods provide complementary information and have high concordance. dMMR endometrial cancers are associated with improved prognosis compared to MMR proficient tumors, especially in early stages. They also predict response to immunotherapy, making dMMR status a crucial factor in treatment decisions. Furthermore, dMMR endometrial cancer raises suspicion for Lynch syndrome. Learn more about incorporating dMMR testing into your endometrial cancer management protocols for personalized patient care and consider referring patients with dMMR tumors for genetic counseling.
Patient presents for evaluation of possible Lynch syndrome given personal andor family history of colorectal cancer, endometrial cancer, or other Lynch syndrome-associated cancers. Patient reports (detailed family history including age at diagnosis, specific cancer type, and relationship to the patient). Patient's personal cancer history includes (list diagnoses, age at diagnosis, and treatment). Physical examination is unremarkable pertinent to Lynch syndrome screening. Mismatch repair MMR testing is indicated to assess for deficient mismatch repair proteins, specifically MLH1, MSH2, MSH6, and PMS2, which may indicate Lynch syndrome. Genetic counseling is recommended to discuss the benefits, risks, and limitations of MMR testing and to facilitate informed consent. Testing options including immunohistochemistry IHC andor polymerase chain reaction PCR based microsatellite instability MSI testing of tumor tissue were discussed. A referral to genetic counseling and authorization for MMR testing were provided. Differential diagnoses include hereditary nonpolyposis colorectal cancer HNPCC, familial colorectal cancer, sporadic colorectal cancer, and other inherited cancer syndromes. Plan is to review MMR test results with the patient and coordinate further management, including potential colonoscopy surveillance, upper endoscopy, and other cancer screening recommendations based on test results and genetic counseling. Medical necessity for MMR testing is supported by established guidelines NCCN guidelines and patient's significant family history. ICD-10 code Z13.89 Encounter for screening for other genetic and chromosomal anomalies and CPT code 81302 Molecular Pathology Level 2 if testing includes MSI and IHC or 88342 Pathology consultation will be used for billing purposes based on the final testing performed.