Regresión espontánea de carcinoma epidermoide infiltrante de orofaringe

Abstract

Introduction and objective: Spontaneous regression of carcinomas is described only in a few cases within the literature. It´s defined as the disappearance of a tumor, confirmed by a histopathologic study, in the abscense of an adequate treatment. Its a rare phenomenon, though recognized in oncology. The objective of the present work is to present the clinical case of a 75-year-old man, who developed an infiltrating squamous cell carcinoma of the soft palate, that disappeared spontaneously within three months. Tumoral remission was confirmed by an anatomopathologic study. There are many possible mechanisms for this tumoral regression, along the lines of immune system modulation and activation as a result of the trauma caused by the biopsy. Method: This is the case of a 75-year-old man, who consults for a mass in the soft palate of approximately 3 x 5 cms, of a whitish-yellow colour and slightly ulcerated. It had been growing for the last month. The mass covered from the end of the hard palate until the right tonsil pillar. Its aspect was suggestive of malignancy, therefore a CT scan was solicited and a first biopsy taken. Results: The CT scan performed reported an increase in soft tissue that  slightly hyper-uptakes in relation to the rest of soft tissues from that location. It has badly defined contours and was described as suspicious of malignancy. The diagnosis made by the anatomopathologist was of an infiltrating squamous cell carcinoma, excrescent, well differentiated, keratinizing and with superficial invasion of the stroma. A surrogate inmunohistochemical marker for papillomavirus (P16) was performed, with a positive result. Three months later, the lesion presented an important decrease in size. Therapeutical possibilities are presented to the patient: surgery versus radiotherapy. Previous to the patient’s decision, a new biopsy is taken, this time presenting no evidence of malignancy. In this moment, the anatomopathologist studies the first biopsy again, confirming the initial diagnosis of squamous cell carcinoma, well differentiated, keratinizing and with superficial invasion of the stroma. Discussion: There are multiple possible mechanisms involved in tumoral regression, including variation of the immune system modulation. Activation of the immune system, as a result of a biopsy is a possible way to explain the beginning of the process of tumor regression. Conclusions: Spontaneous regression of a carcinoma is a rare, but described phenomenon in oncology. The case described could be explained by the immune system modulation that results from a biopsy, its hypothesized that this could trigger a response in the immune system that culminates in tumoral regression. Neoplasms evade the immune system by hiding from it, when taking a biopsy, tissue damage is produced exposing the tumor´s specific antigens to the immune system and activating an immune response. When facing a tumoral regression, with macroscopic disappearance of the mass, a hystopathological confirmation must be made. Given that there is very few knowledge about the underlying mechanism to this, it is important to follow up these cases closely.