When is medullary thyroid carcinoma “medullary thyroid carcinoma”?

Medullary thyroid carcinoma (MTC) is thought to develop from the parafollicular or C cells within the thyroid gland and, therefore, should not take up radioactive iodine. Recently, however,¹³¹I uptake has been reported in metastases of medullary carcinoma and, consequently, some authors have suggested that these tumors can be treated with radioactive iodine. On the basis of observations in 5 patients out of 11 with MTC, we would like to comment regarding this situation. In our 5 patients who were treated by total thyroidectomy, the diagnosis of medullary carcinoma was made by experienced pathologists using immunohistochemical staining methods (calcitonin and/or thyroglobulin), peroxidase-antiperoxidase techniques, and electron microscopy. Evaluation of serum concentrations of calcitonin and serum thyroglobulin by radioimmunoassay was also performed. Data from our 5 patients provide evidence that patients with histopathological and immunohistochemical criteria for medullary thyroid carcinoma, and with high serum calcitonin levels, can take up¹³¹I. It is possible that these tumors represent poorly differentiated thyroid carcinomas with C-cell metaplasia or mixed tumors originating from both follicular and parafollicular cells. Other neoplasms classified as medullary cancer seem to be unspecified thyroid cancers with C-cell hyperplasia in the periphery of the tumor.

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Resumen Se considera que el carcinoma medular de tiroides (CMT) se desarrolla a partir de las células parafoliculares o células C de la glándula tiroidea y, por lo tanto, no debe captar yodo radioactivo. Sinembargo, recientemente se ha informado captación de¹³¹ I por parte de metástasis de carcinoma medular y como consecuencia algunos autores han sugerido que estos tumores pueden ser tratados con yodo radioactivo. Fundamentados en la observación de 5 pacientes entre 11 con CMT, procedemos a comentar esta situación. En 5 pacientes tratados con tiroidectomía total, el diagnosis de carcinoma medular fue hecho por patólogos expertos mediante métodos de coloraciön inmunohistoquímica (calcitonina y/o tiroglobulina), técnicas de peroxidasa-antiperoxidasa y microscopía electrónica. También se realizó la evaluación de las concentraciones séricas de calcitonina y de tiroglobulina sérica por RIA. Los datos obtenidos en nuestros 5 pacientes proveen evidencia de que pacientes con criterios histopatológicos e inmunohistoquímicos para sustentar el diagnosis de carcinoma medular de tiroides y con niveles elevados de calcitonina sérica pueden captar¹³¹I. Es posible que estos tumores representen carcinomas tiroideos pobremente diferenciados con metaplasia de células C o tumores mixtos de origen tanto en células foliculares como parafoliculares. Otros neoplasmas clasificados como carcinoma medular parecen ser cánceres tiroideos no especificados con hiperplasia de células C en la periferia del tumor.

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Résumé Le carcinome médullaire thyroïdien (MTC) est considéré comme se développant à partir des parafollicules ou des cellules C depuis l'intérieur de la glande thyroïde et ne capterait pas, par conséquent, l'iode radioactif. Par contre, récemment, la captation de¹³¹I a été décrite dans les métastases des carcinomes médullaires. Quelques auteurs ont suggéré que ces tumeurs seraient curables par l'iode radioactif. A partir de l'observation de 5 patients parmi 11 ayant un MTC, les auteurs souhaiteraient commenter les constatations précédentes. Ces 5 patients ayant subit une thyroïdectomie totale, le diagnostic de carcinome médullaire a été établi par des anatomopathologistes expérimentés, utilisant des méthodes de colorations immunohistochimiques (calcitonine et/ou thyroglobuline), des techniques de peroxydase-antiperoxydase et de microscopic électronique. Les concentrations sériques de calcitonine et de thyroglobuline sont dosées par RIA. Les données obtenues montrent à l'évidence que les patients ayant des critères histopathologiques et immunohistologiques de carcinome médullaire thyroïdien avec un taux sérique élevé de calcitonine peuvent capter¹³¹I. Il est possible que ces tumeurs représentent des carcinomes thyroïdiens peus différentiés avec métaplasie des cellules C ou des tumeurs mixtes ayant pour origine à la fois les cellules folliculaires et parafolliculaires. Les autres néoplasmes classés comme cancers médullaires semblent être des cancers thyroïdiens non spécifiques avec hyperplasie des cellules C en périphérie de la tumeur.

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Presented at the International Association of Endocrine Surgeons in Paris, September 1985.     

When should secondary procedures be performed in residual hip dysplasia?

Residual hip dysplasia is one of the most important complications following treatment of developmental hip dysplasia. If untreated, this condition will cause problems during maturity. The acetabulum consists of the ilium, ischium, pubis, and the triradiate cartilage lying between them. Interstitial growth from the growth plates of the triradiate cartilage plays an important role in the development of the acetabulum. Concentricity and congruity should be maintained during this development, which is very fast during the first eight years and continues until maturity. Whether residual hip dysplasia will occur can be anticipated by evaluating the factors that are effective on this development during the treatment of developmental hip dysplasia. The main prognostic factors include the age of the patient, concentricity and congruity of the hip, sphericity of the femoral head, the distance from the center to the head, and the thickness of the acetabular roof. Taking these factors into consideration during the follow-up is important to eliminate overtreatment and to assess the success of treatment.     

Somatic mutations in the RET protooncogene in Japanese and Chinese sporadic medullary thyroid carcinomas

Objective.Despite advances in the understanding of the genotype-phenotype correlation in multiple endocrine neoplasia type 2A and 2B(MEN 2A,MEN 2B),and familial medullary thyroid carcinoma (FMTC),the frequency and prognostic relevance of RET protoonco-gene mutations in sporadic medullary thyroid carcinomas (MTCs) remain controversial.Methods To study somatic mutations in the RET protooncogene in Japanese and Chinese sporadic MTCs and to comparatively analyze the correlation between RET mutation and tumor differentiation,we in-vestigated somatic mutations in the RET protooncogene in 20 Japanese and 20 Chinese sporadic MTCs by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.Results Of the 40 sporadic MTCs,13 had a point mutation in codon 918 of exon 16,a frequency of 32.5%。There was no significant difference in the frequency between Japanese and Chinese sporadic MTCs,as 30% of the Japanese and 35% of the Chinese sporadic MTCs contained this mutation.We did not observe any correlation between the presence or absence of codon 918 mutation and tumor differentiation in either Japanese or Chinese sporadic MTCs.Conclusion Our findings indicate that the frequency of RET somatic mutations is similar in Japanese and Chi-nese sporadic MTCs,and the presence or absence of RET mutation does not correlate with the differentiation of sporadic MTCs.     

Renal cell carcinoma: should radical nephrectomy be performed in the presence of metastatic disease?

Metastatic renal cell carcinoma is associated with an unfavorable prognosis and the treatment options are limited. Adjunctive radical nephrectomy, performed either before or after the administration of systemic immunotherapy, has been proposed as a means of improving outcome. The role of nephrectomy for patients with metastatic disease remains controversial. This article reviews the role of nephrectomy in metastatic renal cell carcinoma and the optimal timing for surgery relative to immunotherapy.     

When should peripheral lymphadenopathy be biopsied?

Excisional biopsy for lymphadenopathy is sometimes necessary to confirm the diagnosis of lymphoma or metastatic disease from an unknown primary site. Lymph node excision should be preceded by less invasive approaches which may confirm a benign pathology. Collaboration with medical and hematologic specialists will allow a well-reasoned diagnostic approach with complementary studies; excisional biopsy, if necessary, will then be done under the best conditions and in the most cost-efficient manner.     

The surgical choice for unilateral thyroid carcinoma in pediatrics: Lobectomy or total thyroidectomy?

Background

Total thyroidectomy is no doubt the standard procedure for patients with bilateral thyroid carcinoma in pediatrics. However, for lesions confined in unilateral thyroid gland, lobectomy or radical total thyroidectomy is still controversial in pediatrics.

Decompressive surgery in acute head injuries: where should it be performed?

BACKGROUND: In Norway, most patients with severe head injuries are transported to, and operated in, the neurosurgical unit of the regional university hospital. However, some patients are still occasionally operated on in county central hospitals by orthopedic or general surgeons who do not have neurosurgical expertise. The aim was to analyze this surgical activity outside the neurosurgical units. METHODS: Data were collected from two sources: a nation-wide survey and the records of all patients with a severe head injury occurring within Vestfold county (1987-1996). RESULTS: The Norwegian county central hospitals perform each only 2.5 to 3 surgical evacuations of intracranial hematomas per year. In Vestfold county, a total of 161 patients were hospitalized alive with an acute severe head injury. One third of the patients (54 patients) underwent decompressive surgery, mostly evacuations of intracranial hematomas. The patients operated on in the central hospital had a significantly worse outcome than the patients who were transferred to and operated on in the neurosurgical unit of the regional hospital. Only patients with extracerebral hematomas were operated on in the central hospital. Patients with an extradural (epidural) hematoma had a better outcome than patients with an acute subdural hematoma. Based on the surgery records and preoperative and postoperative computed tomographic scans, one third of the operations (10 operations) in the central hospital were classified retrospectively as inadequate, because the hematoma was not evacuated or found or because the surgeons did not achieve control of the perioperative bleeding. The overall mortality rate was 29.8%. CONCLUSION: The present study indicates that, in Norway and countries with a similar hospital system, it must be difficult for general and orthopedic surgeons to achieve and maintain the skills required for emergency operations in patients with acute severe head injuries. Thus, it is probably to the patients' benefit to improve the general hospitals' competency and speed in the detection of candidates for surgical decompression, and stress the importance of these patients being transferred without unnecessary delay to a neurosurgical unit.     

Should laparoscopic cholecystectomy be performed in patients with thick-walled gallbladder?

Background/Purpose Laparoscopic cholecystectomy is the procedure of choice for patients with symptomatic cholelithiasis. This procedure is contraindicated in patients with gall-bladder cancer (GBC) because of fear of dissemination of the disease. One of the findings raising the suspicion of GBC is a thick-walled gallbladder (TWGB).Methods A prospective study of patients with TWGB was done over a period of 10 months at a tertiary-level referral hospital in northern India. We studied the clinical profiles, investigations (ultrasound [US] and computerized tomography [CT]) and management plans in these patients.Results A total of 60 patients were included in the study. After cholecystectomy, histopathology of gallbladders showed GBC in 2 (3.3%) patients. The remaining 58 patients had chronic cholecystitis, of whom 28 (48%) had xanthogranulomatous variant chronic cholecystitis. Cholecystectomy by the laparoscopic method was attempted in 46 (77%) patients and by open technique in the remaining 14 (23%) patients. Laparoscopic cholecystectomy was successful in 40 of the 46 (87%) patients in whom it was attempted. Obscure anatomy, suspicion of GBC, and bile duct injury were the causes of conversion, in the remaining 13% (6/46). None of the 11 patients who had a CT examination because of clinical or US suspicion of malignancy turned out to have GBC at final histology. Both the cases of GBC in this study were incidental findings on final histopathology.Conclusions Laparoscopic cholecystectomy can be successfully performed in the majority of patients with diffuse TWGB, with appropriate selection. There is, however, an increased chance of conversion to open cholecystectomy in these patients. If there is an intraoperative suspicion of GBC, early conversion to open cholecystectmy and frozen section/imprint cytology will help to decide the further treatment during surgery.