The coronavirus disease (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread exponentially worldwide. In Brazil, the number of infected people diagnosed has been increasing and, as in other countries, it has been associated with a high risk of contamination in healthcare teams. For healthcare professionals, the full use of personal protective equipment (PPE) is mandatory, such as wearing surgical or filtering facepiece class 2 (FFP2) masks, waterproof aprons, gloves, and goggles, in addition to training in care processes. A reduction in the number of face-to-face visits and non-essential elective procedures is also recommended. However, surgery should not be postponed in the case of the most essential elective indications (mostly associated with head and neck cancers). As malignant tumors of the head and neck are clinically time sensitive, neither consultations for these tumors nor their treatment should be postponed. Postponing surgical treatment can result in a change in the disease stage and alter an individual's chance of survival. In this situation, planning of all treatments must begin with the request for, in addition to routine examinations, a nasal swab polymerase chain reaction for SARS-CoV-2 and chest computed tomography. Only if the results of these tests are positive or if fever or other symptoms suggestive of COVID-19 are present should the surgical procedure be postponed until the patient completely recovers. This is mandatory not only because of the risk of contamination of the surgical team but also because of the increased risk of postoperative complications and high risk of death. During this pandemic, the most effective safety measures are social distancing for the general public and the adequate availability and use of PPE in the healthcare field. The treatment of other chronic diseases, such as cancer, should be continued, as the damming of cases of these diseases will have a deleterious effect on the public healthcare system.

We briefly review the surgical approaches to medullary thyroid carcinoma associated with multiple endocrine neoplasia type 2 (medullary thyroid carcinoma/multiple endocrine neoplasia type 2). The recommended surgical approaches are usually based on the age of the affected carrier/patient, tumor staging and the specific rearranged during transfection codon mutation. We have focused mainly on young children with no apparent disease who are carrying a germline rearranged during transfection mutation. Successful management of medullary thyroid carcinoma in these cases depends on early diagnosis and treatment. Total thyroidectomy should be performed before 6 months of age in infants carrying the rearranged during transfection 918 codon mutation, by the age of 3 years in rearranged during transfection 634 mutation carriers, at 5 years of age in carriers with level 3 risk rearranged during transfection mutations, and by the age of 10 years in level 4 risk rearranged during transfection mutations. Patients with thyroid tumor >5 mm detected by ultrasound, and basal calcitonin levels >40 pg/ml, frequently have cervical and upper mediastinal lymph node metastasis. In the latter patients, total thyroidectomy should be complemented by extensive lymph node dissection. Also, we briefly review our data from a large familial medullary thyroid carcinoma genealogy harboring a germline rearranged during transfection Cys620Arg mutation. All 14 screened carriers of the rearranged during transfection Cys620Arg mutation who underwent total thyroidectomy before the age of 12 years presented persistently undetectable serum levels of calcitonin (<2 pg/ml) during the follow-up period of 2-6 years. Although it is recommended that preventive total thyroidectomy in rearranged during transfection codon 620 mutation carriers is performed before the age of 5 years, in this particular family the surgical intervention performed before the age of 12 years led to an apparent biochemical cure.

INTRODUCTION: Medullary thyroid carcinoma may occur in a sporadic (s-medullary thyroid carcinoma, 75%) or in a multiple endocrine neoplasia type 2 form (MEN2, 25%). These clinical forms differ in many ways, as s-medullary thyroid carcinoma cases are RET-negative in the germline and are typically diagnosed later than medullary thyroid carcinoma in MEN2 patients. In this study, a set of cases with s-medullary thyroid carcinoma are documented and explored. PURPOSE: To document the phenotypes observed in s-medullary thyroid carcinoma cases from a university group and to attempt to improve earlier diagnosis of s-medullary thyroid carcinoma. Some procedures for diagnostics are also recommended. METHOD: Patients (n=26) with apparent s-medullary thyroid carcinoma were studied. Their clinical data were reviewed and peripheral blood was collected and screened for RET germline mutations. RESULTS: The average age at diagnosis was 43.9 years (± 10.82 SD) and did not differ between males and females. Calcitonin levels were increased in all cases. Three patients presented values that were 100-fold greater than the normal upper limit. Most (61.54%) had values that were 20-fold below this limit. Carcinoembryonic antigen levels were high in 70.6% of cases. There was no significant association between age at diagnosis, basal calcitonin levels or time of disease onset with thyroid tumor size (0.6-15 cm). Routine thyroid cytology yielded disappointing diagnostic accuracy (46.7%) in this set of cases. After total thyroidectomy associated with extensive cervical lymph node resection, calcitonin values remained lower than 5 pg/mL for at least 12 months in eight of the cases (30.8%). Immunocyto- and histochemistry for calcitonin were positive in all analyzed cases. None of the 26 cases presented germline mutations in the classical hotspots of the RET proto-oncogene. CONCLUSION: Our cases were identified late. The basal calcitonin measurements and immunostaining for calcitonin were highly useful for diagnosing s-medullary thyroid carcinoma. The rate of complete patient recovery was low, and none of the parameters analyzed were useful predictors of the thyroid tumor size. Our findings support previous recommendations for routine serum calcitonin evaluation and immunostaining analysis involving single thyroid nodules.

Hypercalcitoninemia has frequently been reported as a marker for medullary thyroid carcinoma. Currently, calcitonin measurements are mostly useful in the evaluation of tumor size and progression, and as an index of biochemical improvement of medullary thyroid carcinomas. Although measurement of calcitonin is a highly sensitive method for the detection of medullary thyroid carcinoma, it presents a low specificity for this tumor. Several physiologic and pathologic conditions other than medullary thyroid carcinoma have been associated with increased levels of calcitonin. Several cases of thyroid nodules associated with increased values of calcitonin are not medullary thyroid carcinomas, but rather are related to other conditions, such as hypercalcemias, hypergastrinemias, neuroendocrine tumors, renal insufficiency, papillary and follicular thyroid carcinomas, and goiter. Furthermore, prolonged treatment with omeprazole (> 2-4 months), beta-blockers, glucocorticoids and potential secretagogues, have been associated with hypercalcitoninemia. An association between calcitonin levels and chronic auto-immune thyroiditis remains controversial. Patients with calcitonin levels >100 pg/mL have a high risk for medullary thyroid carcinoma (~90%-100%), whereas patients with values from 10 to 100 pg/mL (normal values: <8.5 pg/mL for men, < 5.0 pg/mL for women; immunochemiluminometric assay) have a <25% risk for medullary thyroid carcinoma. In multiple endocrine neoplasia type 2 (MEN2), RET mutation analysis is the gold-standard for the recommendation of total preventive thyroidectomy to relatives at risk of harboring a germline RET mutation (50%). False-positive calcitonin results within MEN2 families have led to incorrect indications of preventive total thyroidectomy to RET mutation negative relatives. In this review, we focus on the differential diagnosis of hypercalcitoninemia, underlining its importance for the avoidance of misdiagnosis of medullary thyroid carcinoma and consequent incorrect recommendation for thyroid surgery.

OBJETIVO: Descrever as dificuldades da endoscopia de contato aplicada à boca e ao lábio (microestomatoscopia de contato) e aplicar nas lesões do lábio os critérios usados na endoscopia de contato de outras topografias. MÉTODO: Estudo prospectivo utilizando o endoscópio de contato Storz 8715A e o corante azul de toluidina. Vinte exames foram feitos para aprendizado da técnica e depois mais 31 (21 lesões do lábio e 10 da boca), todos exames in vivo. Os critérios avaliados foram: Celularidade, Arquitetura, Estratificação e Morfologia. RESULTADOS: A falta de nitidez, os tremores finos e o deslizamento do aparelho dificultaram o procedimento em 100% dos casos, mas permitiram um exame adequado. Os 13 diagnósticos de malignidade das lesões do lábio apresentaram todos os critérios alterados. CONCLUSÃO: as dificuldades encontradas foram o contato do aparelho com a superfície anatômica, o deslizamento do aparelho, os tremores finos e a falta de nitidez da imagem, que não inviabilizaram a realização e a interpretação do exame. Os critérios são aplicáveis às lesões da boca e do lábio inferior.

BACKGROUND: 1- To describe difficulties of contact endoscopy related to mouth and lip (contact microstomatoscopy) and 2- apply the criteria used in contact endoscopy of other topographies when lip lesions are diagnosed. METHODS: A prospective study was performed with the contact endoscope Storz 8715A and toluidine blue was used. Twenty examinations were accomplished in order to learn the technique; after that, other 31 were included (21 lip lesions and 10 oral lesions), all in vivo examinations. The criteria assessed were: cellularity, architecture, stratification and morphology. RESULTS: Lack of image clearness, slight tremors and sliding of the equipment made the procedure difficult in 100% of the cases; even though, accomplishment of proper examination was obtained. The 13 cases of lip malignancy lesions had the criteria altered as a whole. CoNCLUSION: Difficulties found were the contact of the equipment with anatomic surface, the sliding of the equipment, the slight tremors, and the lack of image clearness. Nevertheless, such elements did not interrupt the accomplishment and the examination analysis. The criteria are applied to oral and lower lip lesions.

We theoretically study many-body excitations in three different quasi-one-dimensional (Q1D) electron systems: (i) those formed on the surface of liquid Helium; (ii) in two coupled semiconductor quantum wires; and (iii) Q1D electrons embedded in polar semiconductor-based quantum wires. Our results show intersubband coupling between higher subbands and the two lowest subbands affecting even the lower energy intersubband plasmons on the liquid Helium surface. Concerning the second system, we show a pronounced extra peak appearing in the intersubband impurity spectral function for temperatures as high as 20 K. We finally show coupled intersubband plasmon-phonon modes surviving for temperatures up to 300 K.

OBJETIVO: Caracterizar epidemiológica e clinicamente a população atendida por câncer de boca em hospital-escola de atenção terciária e quaternária e verificar variações em relação a outras casuísticas e períodos. MÉTODO: Procedeu-se à revisão dos prontuários dos operados por câncer oral de 1994 a 2002. As características clínicas e epidemiológicas foram colocadas em planilhas e analisadas. RESULTADOS: Foram identificados 374 portadores de câncer da boca que foram submetidos a 406 operações. A idade dos doentes variou de 14 a 94 anos (média = 57,4 anos). Duzentos e cinqüenta e cinco eram do gênero masculino (68,2%). Duzentos e noventa e cinco entre 366 doentes eram caucasianos (80,6%). A maioria era portadora de tumores da língua e/ou do soalho da boca (194 entre 349 doentes; 55,6%), e 71 (20,3%) tinham tumores dos lábios. O carcinoma epidermóide foi encontrado em 90,3% e carcinomas glandulares em 4%. Os tumores T4 estavam presentes em 39,6% dos doentes; 15,2% tinham lesões Tis ou T1. Quase 62% dos pacientes não tinham metástases cervicais. A incidência relativa em jovens (com até 40 anos de idade) atingiu 8,6%. CONCLUSÃO: Apesar dos achados freqüentemente referidos na literatura terem se confirmado (como o predomínio de lesões avançadas localmente), a maioria dos doentes não apresentava metástases cervicais. Acima do observado em outras casuísticas, os 31,8% de mulheres na presente casuística indica a preocupante e crescente incidência no gênero feminino.

PURPOSE: Description of clinical and epidemiological characteristics of patients who underwent surgery for oral cancer in a Medical School Teaching Hospital, and determination of differences with respect to other institutions and/or periods of time. METHOD: The charts of patients undergoing surgery for oral cancer from 1994 to 2002 were reviewed. Data were collected in a spreadsheet in order to analyze clinical and epidemiological features.. RESULTS: A total of 374 patients having undergone 406 operations was identified. Their ages varied from 14 to 94 years (mean = 57.4 years), with 255 men (68.2%), and 295 out 366 Caucasian (80.6%). A majority had tumors of the tongue and/or floor of mouth (55.6%), while 20.3% had lip cancer. Squamous cell carcinoma was found in 90.3%, and glandular carcinoma in 4%. T4 tumors in 39.6%, Tis or T1 lesions in 15.2% of all patients. Nearly 62% had no regional metastases, and the relative incidence in young patients (40 years or younger) reached 8.6%. CONCLUSION: In spite of the predominance of locally advanced tumors, a majority of patients had no neck metastases. The 31.8% incidence in females indicates an increasing incidence of oral cavity cancer among women when compared to previous periods at the same institution.

OBJETIVO: A ocorrência de carcinoma papilífero da tireóide (CPT) em doentes com hiperparatireoidismo (HPT) suscita dúvidas quanto a ser apenas coincidência ou apresentar relação causal. O objetivo deste trabalho é verificar se a incidência de CPT em diferentes formas de HPT é semelhante entre si e à incidência de CPT em achados de necropsias, assim como em doentes submetidos à tireoidectomia na mesma região. MÉTODO: Os dados de 222 pacientes consecutivos tratados por HPT foram revistos e foi analisada a incidência de CPT. Os pacientes foram estratificados em HPT primário (107) e HPT secundário (115). Os laudos anatomopatológicos foram revistos, a incidência de CPT foi pesquisada e suas características nesses indivíduos foram estudadas. Esses dados foram comparados a dados encontrados em casos de necrópsia e em 89 casos de bócio compressivo/mergulhante. Empregou-se o teste exato de Fisher e o teste t não pareado. RESULTADOS: Os laudos foram passíveis de análise em 103 casos de HPT primário, com 10 pacientes com CPT (9,7%) e em 111 portadores de HPT secundário, com três CPT associados (2,7%). Houve diferença entre o HPT primário e HPT secundário (p=0,04). Essa diferença também foi significativa em relação aos 1% de CPT achados em necrópsia na região (p=0,0001). Não houve diferença com relação à incidência de 11,2% de CPT no grupo operado por compressão e também em relação às características dos tumores, apesar de haver 80% de multicentricidade no CPT de doentes com HPT primário. CONCLUSÕES: A ocorrência de CPT em HPT primário é maior que em HPT secundário e que em achados de necropsia.

BACKGROUND: Association of papillary thyroid carcinoma (PTC) and hyperparathyroidism (HPT) has not been clearly defined. The incidence of PTC in different types of HPT and necropsy or patients submitted to thyroidectomy in the same region is analyzed to verify if this association is casual or not. METHODS: Data of 222 consecutive patients operated for HPT were reviewed and incidence of PTC was defined. Patients were analyzed as primary HPT (107) and secondary (115). The incidence of PTC was compared to that found in necropsy and to that observed in 89 patients with compressive multinodular goiter submitted to thyroidectomy. Statistical analysis included Fisher's exact test and Student's t test. RESULTS: Pathology reports were available in 103 cases of primary HPT, and in 10 patients PTC was detected (9.7%). In 111 secondary HPT patients, PTC was found in three (2.7%), with statistical significant difference between primary and secondary HPT (p=0.04). This difference was also significant of the 1% incidence of PTC found in necropsy in the same area (p=0.0001). No difference was observed in relation to the incidence of 11.2% of PTC found in patients operated for compressive goiter. Tumor characteristics were not statistically different, although multicentricity was detected in 80% of PTC of patients with primary HPT. CONCLUSION: The incidence of PTC was elevated in patients with primary HPT, in relation to necropsy or secondary HPT cases.