A 9-year-old boy was referred to the pediatric otolaryngology clinic with a 3-month history of a left-sided neck mass. The mass had been slowly enlarging and he had been experiencing mild intermittent pain, but no additional symptoms were reported. His medical history was significant for several episodes of upper respiratory infection during the previous winter season, and he previously had an adenotonsillectomy several years prior and bilateral ear tubes placed 1 year before presentation. Physical examination showed a mildly tender, nonmobile, left parotid mass near the angle of the mandible with no overlying skin changes or drainage around the mass. There was no lymphadenopathy or other lesions noted in the neck area, and cranial nerve VII was fully intact. Ultrasonography results of the neck showed a left 1.5-cm preauricular nodular mass with internal and marginal vascularity. A neck magnetic resonance imaging study without contrast performed at an outside institution revealed the 1.5-cm heterogeneous intraparotid nodule that was predominantly isotense to glandular tissue on T1 images with vague hypointensity of a small irregular central region, as well as vague hyperintensity on T2 images. He subsequently underwent fine needle aspiration biopsy to assess the lesion, which demonstrated benign-appearing salivary gland tissue and clusters of myoepithelial cells. The mass was continuing to enlarge, and the patient’s pain was increasing in that area, so the decision was made to perform left superficial parotidectomy with preservation of the facial nerve. Intraoperatively, the left parotid mass was noted to be just below the lower branches of the facial nerve. The excised parotid mass was sent to the pathology department for analysis. Gross examination of the specimen demonstrated a 1.6 × 1.5 × 1.1–cm tan-white, well-circumscribed lesion that was partially surrounded by salivary gland parenchyma (Figure, A). Histologic examination of the nodule was performed (Figure, B and C).
Please finish quiz first before checking answer.
Read the answer below and download your certificate.
Read the discussion below and retake the quiz.
C. Sclerosing polycystic adenoma
Microscopically, hematoxylin-eosin–stained sections demonstrated a well-circumscribed solid mass with a lobular architecture. Within the lesion, there was variably abundant, hyalinized collagen surrounding closely packed ductal structures with varying sizes, some of which were cystically dilated. The lining epithelial cells were bland, and mitotic figures were absent. There were frequent clusters of acinar structures with brightly eosinophilic, intracytoplasmic granules. These characteristic histologic features confirmed the diagnosis of sclerosing polycystic adenoma (SPA).
Sclerosing polycystic adenoma is an uncommon salivary gland tumor first described by Smith et al1 in a series of 9 cases using the term sclerosing polycystic adenosis. Since then, this entity has been increasingly recognized, with more than 100 cases reported so far.2,3 Recently, SPA has been included in the latest edition of the World Health Organization classification of head and neck tumors.4 Sclerosing polycystic adenoma was initially considered to be reactive or inflammatory in nature; however, emerging evidence suggests a clonal process,5 a propensity to recur, and rare instances of malignant transformation.2- 4 Therefore, based on the newly recognized findings, the term sclerosing polycystic adenoma has been proposed to reflect a true neoplastic process.2,3 This notion is further supported by the recent discovery of recurrent gene variations in the PI3K pathway of cell cycle regulation in SPA that are analyzed through targeted next-generation sequencing, with PTEN variations identified in all cases (n = 4).6
Sign in to take quiz and track your certificates
JN Learning™ is the home for CME and MOC from the JAMA Network. Search by specialty or US state and earn AMA PRA Category 1 Credit(s)™ from articles, audio, Clinical Challenges and more. Learn more about CME/MOC
CME Disclosure Statement: Unless noted, all individuals in control of content reported no relevant financial relationships. If applicable, all relevant financial relationships have been mitigated.
Corresponding Author: Jiancong Liang, MD, PhD, Vanderbilt University Medical Center, Monroe Carell Jr. Children's Hospital at Vanderbilt, 2200 Children's Way, 11139 Doctors' Office Tower, Nashville, TN 37232 (firstname.lastname@example.org).
Published Online: February 4, 2021. doi:10.1001/jamaoto.2020.5285
Conflict of Interest Disclosures: None reported.
Additional Contributions: We thank the patient’s mother for granting permission to publish this information.
You currently have no searches saved.
You currently have no courses saved.