Spontaneous Regression Of The Pulmonary Metastases In Adenoid Cystic Carcinoma Of The Parotid Gland: A Case Report
Pokhrel, B., Chidharla, A., & Neupane, P. (2022). Spontaneous Regression of the Pulmonary Metastases in Adenoid Cystic Carcinoma of the Parotid Gland: A Case Report. Cureus, 14(10), e30783. https://doi.org/10.7759/cureus.30783
View Original Source →Abstract
Adenoid cystic carcinoma (ACC) is a rare epithelial tumor of the salivary glands with an indolent course and usually bears a long-term survival rate even when metastasized. Spontaneous regression of such a resistant tumor is an even scarce event. We report a case of a patient with ACC of the parotid gland with pulmonary metastases, which spontaneously resolved following resection and post-surgical radiation of the primary tumor. Among the numerous theories proposed to explain such a phenomenon, immunogenic mechanisms and the abscopal effect are the most plausible explanations in this case.
Case Details
Disease Location
Lungs
Personal Characteristics
64-year-old male. Prostate cancer, which had been resected about two years before his presentation.
Clinical Characteristics
Presented with the complaint of a lump behind his left ear and paresthesia on the left side of his face for two months. CT scan of the head and neck demonstrated a lobular mass within the superior deep lobe of the left parotid gland measuring 1.9 cm x 2.7 cm x 2.45 cm. Fine needle aspiration (fna) biopsy showed a pleomorphic adenoma. The patient underwent left total parotidectomy. The final histopathologic evaluation revealed adenoid cystic carcinoma (acc) with negative margins and negative lymph nodes with no evidence of residual disease. CT chest, multiple pulmonary nodules were seen on both lungs. The largest one measuring 1.6 cm in the right lower lobe, with no other distant metastases. On the biopsy of the right lower lobe lung nodule, cytology consistent with metastatic acc was confirmed. The patient underwent parotid and neck irradiation.
Remission Characteristics
On surveillance CT scans of the lungs, the nodules started regressing and completely disappeared 14 months later, without any systemic therapy
Treatment & Mechanisms
Proposed Remission Mechanisms
Abscopal effect
Clinical Treatment
Biopsy, parotidectomy, radiotherapy