PULMONARY INVOLVEMENT WITH PLEOMORPHIC ADENOMA: 30-YEAR EXPERIENCE WITH THIS RARE ENTITY AT A TERTIARY REFERRAL CENTER

Abstract

SESSION TITLE: Lung Cancer Assessment and Risk CalculationsSESSION TYPE: Rapid Fire Original InvPRESENTED ON: 10/19/2022 11:15 am - 12:15 pmPURPOSE: Salivary gland tumors are rare causes of pulmonary neoplasms, with the most common being adenoid cystic carcinoma. Although pleomorphic adenoma (PA) is the most common benign salivary gland tumor, it can rarely present as a neoplasm within the lungs. We aimed to describe clinical, radiographic and management aspects of this rare tumor managed at our center over 30 years.METHOD: We conducted a retrospective review of all adult patients with pathology-confirmed PA involving the lungs who presented to Mayo Clinic, MN between 1992 to 2022.RESULTS: We identified 13 patients with pathology-confirmed PA, of which 3 had primary airway PA, while 10 had metastatic carcinoma ex pleomorphic adenoma (CePA). Mean age was 62.3 years (SD 4.7) and 7 were female (54%).Of the patients with primary airway PA, 1 presented with cough, 1 with dyspnea and 1 with recurrent hemoptysis. Patients did not have concurrent parotid tumors. All were diagnosed via endobronchial biopsy. Two patients had left mainstem bronchus lesions and were treated with sleeve resection. One patient had a tracheal lesion developing CePA and this patient underwent transcervical resection and tracheal reconstruction, followed by adjuvant radiotherapy. No recurrences were reported.Of those with metastatic CePA, 6 were found incidentally on screening CT, 2 presented with cough, 1 with pneumothorax and 1 with recurrent pleural effusion. The primary parotid malignancy was diagnosed/treated 6 months to 9 years prior to the discovery of pulmonary findings. Most patients (8/10) presented with parenchymal nodules (of which 6 had multiple nodules), 1 had mediastinal lymphadenopathy and 1 had a pleural nodule. Diagnosis was made using CT-guided biopsy in 7 patients, surgical lung biopsy in 2, and EBUS in 1. PET-CT scans were done in 7 patients, and showed variable uptake (SUVmax ranging from 1.1-5.7). Metastatic CePA was treated with observation alone in 4 patients, chemotherapy alone in 4, surgical resection alone in 1, and surgery followed by adjuvant chemotherapy in 1 patient. One patient had disease recurrence after 3 years, which was treated with chemotherapy.CONCLUSIONS: PA can present as a primary airway lesion, airway-centered symptoms (without concurrent parotid gland disease), and treatment is surgical. Metastatic CePA typically presents in the lungs as multiple nodules and rarely with lymphadenopathy, but without airway involvement. It can present years after treatment for the primary parotid CePA and has a very gradual clinical course. The nodules show variable metabolic activity on PET-CT.CLINICAL IMPLICATIONS: PA can present as a primary airway tumor and is treated with surgical resection. Metastatic CePA in the lungs presents as multiple parenchymal nodules with extremely slow progression, and treatment plans are determined by symptoms, organ function compromise and overall functional status.DISCLOSURES: No relevant relationships by Sumedh HoskoteNo relevant relationships by Samrah Razi SESSION TITLE: Lung Cancer Assessment and Risk Calculations SESSION TYPE: Rapid Fire Original Inv PRESENTED ON: 10/19/2022 11:15 am - 12:15 pm PURPOSE: Salivary gland tumors are rare causes of pulmonary neoplasms, with the most common being adenoid cystic carcinoma. Although pleomorphic adenoma (PA) is the most common benign salivary gland tumor, it can rarely present as a neoplasm within the lungs. We aimed to describe clinical, radiographic and management aspects of this rare tumor managed at our center over 30 years. METHOD: We conducted a retrospective review of all adult patients with pathology-confirmed PA involving the lungs who presented to Mayo Clinic, MN between 1992 to 2022. RESULTS: We identified 13 patients with pathology-confirmed PA, of which 3 had primary airway PA, while 10 had metastatic carcinoma ex pleomorphic adenoma (CePA). Mean age was 62.3 years (SD 4.7) and 7 were female (54%).Of the patients with primary airway PA, 1 presented with cough, 1 with dyspnea and 1 with recurrent hemoptysis. Patients did not have concurrent parotid tumors. All were diagnosed via endobronchial biopsy. Two patients had left mainstem bronchus lesions and were treated with sleeve resection. One patient had a tracheal lesion developing CePA and this patient underwent transcervical resection and tracheal reconstruction, followed by adjuvant radiotherapy. No recurrences were reported.Of those with metastatic CePA, 6 were found incidentally on screening CT, 2 presented with cough, 1 with pneumothorax and 1 with recurrent pleural effusion. The primary parotid malignancy was diagnosed/treated 6 months to 9 years prior to the discovery of pulmonary findings. Most patients (8/10) presented with parenchymal nodules (of which 6 had multiple nodules), 1 had mediastinal lymphadenopathy and 1 had a pleural nodule. Diagnosis was made using CT-guided biopsy in 7 patients, surgical lung biopsy in 2, and EBUS in 1. PET-CT scans were done in 7 patients, and showed variable uptake (SUVmax ranging from 1.1-5.7). Metastatic CePA was treated with observation alone in 4 patients, chemotherapy alone in 4, surgical resection alone in 1, and surgery followed by adjuvant chemotherapy in 1 patient. One patient had disease recurrence after 3 years, which was treated with chemotherapy. CONCLUSIONS: PA can present as a primary airway lesion, airway-centered symptoms (without concurrent parotid gland disease), and treatment is surgical. Metastatic CePA typically presents in the lungs as multiple nodules and rarely with lymphadenopathy, but without airway involvement. It can present years after treatment for the primary parotid CePA and has a very gradual clinical course. The nodules show variable metabolic activity on PET-CT. CLINICAL IMPLICATIONS: PA can present as a primary airway tumor and is treated with surgical resection. Metastatic CePA in the lungs presents as multiple parenchymal nodules with extremely slow progression, and treatment plans are determined by symptoms, organ function compromise and overall functional status. DISCLOSURES: No relevant relationships by Sumedh Hoskote No relevant relationships by Samrah Razi