title: Clinicopathological and Targeted Exome Gene Features of a Patient with Metastatic Acinic Cell Carcinoma of the Parotid Gland Harboring an ARID2 Nonsense Mutation and CDKN2A/B Deletion.
abstract: We describe the presentation, treatment, clinical outcome, and targeted genome analysis of a metastatic salivary acinic cell carcinoma (AciCC). A 71-year-old male presented with a 3 cm right tail of a parotid lesion, first detected as a nodule by the patient seven months earlier. He had a right total parotidectomy with cranial nerve VII resection, right facial nerve resection and grafting, resection of the right conchal cartilage, and right modified radical neck dissection. The primary tumor revealed AciCC with two distinct areas: a well-differentiated component with glandular architecture and a dedifferentiated component with infiltrative growth pattern associated with prominent stromal response, necrosis, perineural invasion, and cellular pleomorphism. Tumor staging was pT4 N0 MX. Immunohistochemistry staining showed pankeratin (+), CD56 (-), and a Ki67 proliferation index of 15%. Upon microscopic inspection, 49 local lymph nodes resected during parotidectomy were negative for cancer cells. Targeted sequencing of the primary tumor revealed deletions of CDKN2A and CDKN2B, a nonsense mutation in ARID2, and single missense mutations of unknown significance in nine other genes. Despite postoperative localized radiation treatment, follow-up whole body PET/CT scan showed lung, soft tissue, bone, and liver metastases. The patient expired 9 months after resection of the primary tumor.
authors.affiliation: Division of Oncology, Siteman Cancer Center, Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
authors.forename: Wayne A
authors.initials: WA
authors.lastname: Warner
authors.affiliation: Division of Hematology-Oncology, Department of Medicine, University of California, Los Angeles, CA 90095, USA.
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Wong
authors.affiliation: Department of Pathology and Laboratory Medicine, University of California, Los Angeles, CA 90095, USA.
authors.forename: Fernando
authors.initials: F
authors.lastname: Palma-Diaz
authors.affiliation: Department of Head & Neck Surgery, Southern California Permanente Medical Group, Anaheim, CA 92806, USA ; Department of Otolaryngology-Head & Neck Surgery, University of California Irvine School of Medicine, Orange, CA 92868, USA.
authors.forename: Terry Y
authors.initials: TY
authors.lastname: Shibuya
authors.affiliation: Department of Chemistry and Biochemistry, California State University, Los Angeles, Los Angeles, CA 90032, USA.
authors.forename: Jamil
authors.initials: J
authors.lastname: Momand