A rare case of adenoid cystic carcinoma of the lung

SESSION TITLE: Lung Cancer Case Report Posters 16 SESSION TYPE: Case Report Posters PRESENTED ON: 10/09/2023 02:10 pm - 02:55 pm INTRODUCTION: Adenoid cystic carcinoma (ACC) is a rare cancer that most commonly develops in the salivary glands or regions of the head and neck. ACC can occur in other parts of the body such as the skin, prostate, cervix, lungs and various other areas. It is considered a low-grade malignancy with slow growth that does not require systemic therapy unless symptomatic, even in the metastatic setting. We present a rare case of primary adenoid cystic carcinoma that is localized to the lung. CASE PRESENTATION: A 68-year-old female former smoker presented to her pulmonologist's office for evaluation of a non-productive cough and dyspnea on exertion. Her physical exam was within normal limits. CT scan of chest demonstrated a nodular lesion 1.6 x 1.3 cm associated with a segmental bronchus in the anterior right upper lobe and PET scan revealed increased FDG uptake of the lesion. The patient underwent robotic assisted bronchoscopy with biopsy and EBUS with TBNA revealing adenoid cystic carcinoma (Figure a) without nodal involvement. The patient underwent surgical resection with robotic assisted right upper lobe lobectomy with a lymph node dissection. Histology showed a neoplasm composed of small to medium cells with eosinophilic to clear cytoplasm, oval to angulated nuclei, basophilic chromatin, occasional small nucleoli and eosinophilic hyalinized stroma.. The tumor cells were arranged in cribriform, tubular and solid patterns (Figure b). Mitotic figures were rare. High grade transformation was not seen. Perineural invasion was present (Figure c). Bronchovascular margins were negative for carcinoma and all lymph nodes were negative for metastatic carcinoma. No adjuvant treatment was needed given the pathology and the patient continued outpatient post-operative follow up with improvement in her symptoms. DISCUSSION: Primary adenoid cystic carcinoma of the lung (ACCL) is an extremely rare neoplasm accounting for only 0.04%-0.2% of all primary lung cancers. Most of these neoplasms originate in the trachea or main bronchus, and ACC of the peripheral lung, as seen in our case, is rarer still. Due to its very low incidence, there is a lack of consensus on treatment guidelines and long-term survival and surveillance. [1] ACC demonstrates three main histological findings on pathology with the most common being a cribriform pattern followed by a tubular pattern. Least frequently seen and most aggressive is the solid pattern which is also more associated with metastasis. [2] Lymphatic and vascular invasion is uncommon, but perineural invasion has been reported in several cases. 60 –90% carry MYB-NFIB or MYBL1-NFIB fusion. Our case is noteworthy in that her pathology demonstrated all three histological patterns as well as perineural invasion. CONCLUSIONS: This case highlights a rare presentation of primary adenoid cystic carcinoma of the lung treated with curative robot assisted surgical resection. REFERENCE #1: Krifa M, Bdioui A, Lajmi Z, Missaoui N, Hmissa S, Mokni M. Primary adenoid cystic carcinoma of the lung: A case report and literature review. Heliyon. 2021 Feb 5;7(2):e06206. doi: 10.1016/j.heliyon.2021.e06206. PMID: 33598583; PMCID: PMC7868598 REFERENCE #2: Hu MM, Hu Y, He JB, Li BL. Primary adenoid cystic carcinoma of the lung: Clinicopathological features, treatment and results. Oncol Lett. 2015 Mar;9(3):1475-1481. doi: 10.3892/ol.2015.2859. Epub 2015 Jan 8. PMID: 25663934; PMCID: PMC4314995. DISCLOSURES: No relevant relationships by Vincent Dong No relevant relationships by Dominick Guerrero No relevant relationships by MANJU HARSHAN No relevant relationships by Matthew Inra No relevant relationships by Viera Lakticova No relevant relationships by Subroto Paul No relevant relationships by Eby Thekkedath