Caracterização clínico-patológica do Carcinoma Escamocelular primário de boca: um estudo transversal com ênfase na categorização histológica dos elementos tumorais e estromais

Abstract

Squamous cell carcinoma (SCC) is the most common malignant neoplasm in the mouth and preferentially affects adult male patients and is associated with risk factors such as smoking and alcohol consumption. Its histopathological classification is generally based on the characteristics of the tumor, while the characteristics of the stroma are not usually considered. This research aimed to characterize the clinicopathological profile of primary oral SCC in newly diagnosed patients, with emphasis on the morphological categorization of tumor and stromal elements. The study was characterized as observational, cross-sectional, based on evaluations of surgical specimens included over a period of 10 years, from patients diagnosed with SCC of the mouth from three services in the city of Manaus. For the histopathological analysis of conventional SCCs, 11 histopathological parameters were considered, including six tumor elements (degree of keratinization, pattern of invasion, arrangement of cellular arrangements, tumor budding; nuclear pleomorphism and amount of mitoses), three stromal elements (maturation profile of the stroma, profile of the peritumoral inflammatory infiltrate and profile of infiltrating lymphocytes of the tumor stroma), and an intermediate element (tumor-stroma relationship). Additionally, malignancy scores were categorized, based on Bryne's classification (1992) as well as items recommended by the College of American Pathologists (CAP). The Chi-square test and Fisher's Exact test were used, considering a significance level of 5%, in order to verify the association between tumor and stromal elements with each other (isolated and in combination), as well as the different histological subtypes of SCC. . Of the 121 patients found, 30 of them were included in the study, 28 cases of conventional SCC and 2 of the Cuniculatum variant of SCC, according to the WHO. The majority of patients were male (73%; n=22), with a mean age of 59 years and the main location was the tongue (70%; n=21), thus the most common surgical procedure performed was partial glossectomy . According to the CAP criteria, the morphological findings of conventional SCC cases showed that the majority presented lymphovascular invasion, invasion depth >10 mm. According to the criteria proposed in the work, the majority presented the following profile: a) For tumor elements: moderate degree of keratinization (Grade 2: 35.7%); pattern of invasion in small groups (not less than 15 cells) or infiltrating cords (Grade 3: 46.4%); cellular arrangement predominantly in islands (35.8%) and cords (32.1%) and low intensity/absence of tumor growths (71%). As for pleomorphism, the extension percentage criterion showed a cell population with abundant pleomorphism (grade 3: 60.7%) and as for the qualitative criterion, moderately pleomorphic cells characterized by nuclei 1.5 to 2 times larger and inconspicuous nucleoli ( score 2: 53.6%). Regarding the presence of mitoses, the majority presented Score 1: ≤ 12 mitoses/10 high power fields (CMA), followed by Score 2: 13-24 mitoses/10 CMA. b) For stromal elements: stromal maturation profile, 46% of cases had immature stroma; TILs profile 46% were categorized into Stromal Category I; and peritumoral inflammatory infiltrate profile, 50% of cases were described as Grade 2, defined as moderate; c) Assessment of the tumor-stroma ratio showed that 68% of cases were in the low category and 32% in the high category. d) Bryne's classification showed that 64% of cases were categorized with low malignancy scores and 36% with high malignancy scores. Some tumor and stromal elements revealed significant associations, such as degree of keratinization versus histological differentiation (p=0.013), pattern of invasion versus predominant cellular arrangement (p=0.003), pattern of invasion versus tumor budding (p<0.001) , predominant cellular arrangement arrangement versus tumor buddings (p=0.008), tumor buddings versus nuclear pleomorphism (p=0.36). There was also a significant association between tumor-stroma relationship versus TILs (p=0.008), peritumoral inflammatory infiltrate profile versus TILs (p=0.028), peritumoral inflammatory infiltrate profile versus depth of invasion (p=0.014). The clinical and epidemiological profile of patients diagnosed with primary SCC of the mouth in the Amazon region is similar to the Amazon region, characterized by male patients, over 60 years of age, with lesions on the tongue. The associations found in this study, between histological elements, such as tumor budding associated with the invasion pattern and arrangement of the predominant cellular arrangement, may indicate potential prognostic signals to be included in the pathologist's routine in the future.