A recent publication by researchers at Fox Chase Cancer Center details a case where a patient was diagnosed with adenoid cystic carcinoma (ACC) following the identification of an atypical fusion gene through molecular testing. The study emphasizes the role of molecular diagnostics in accurately identifying certain cancers.
The first author, an Associate Professor and Medical Director of the Clinical Genomics Laboratory at Fox Chase, explained that their report aims to highlight that the absence of typical MYB/MYBL1 fusion genes does not eliminate ACC as a diagnosis. Instead, the presence of a novel NFIB fusion gene can also be indicative.
“It’s a simple case report, but it’s important information for practicing pathologists to be aware of this potential pitfall,” said Wei.
ACC is a common malignancy affecting salivary glands and generally has a poor long-term prognosis. While typically diagnosable via biopsy, challenges arise when tumors appear in unusual forms or locations, as was the situation in this instance.
Initially identified as a salivary gland neoplasm, the 1.7-centimeter palate tumor tested negative for two commonly used fusion genes for ACC identification: MYB::NFIB or MYBL1::NFIB. However, molecular testing revealed another fusion gene, NFIB::PHACTR2.
Wei highlighted the significance of all three fusion genes sharing NFIB as a common partner. “If you have an NFIB fusion gene in a salivary gland tumor, it is most likely an adenoid cystic carcinoma,” he stated.
Accurate diagnosis is crucial since ACC’s aggressive nature requires different treatment strategies compared to other tumors. This may involve nerve removal or excising more tissue during surgery to ensure clear margins.
“It’s personalized medicine,” Wei remarked. “That’s why we need to do molecular testing before surgery. If we have the accurate diagnosis, we can give the patient better management and treatment.”
He also pointed out that molecular testing is not yet widely accessible and might not be available at smaller community hospitals. He advised referring cases to specialized cancer centers for confirmation.
The paper was published in Virchows Archiv, which serves as the official journal of the European Society of Pathology.
