Prevalence of cystic metastases in a consecutive cohort of surgically removed branchial cleft cysts

BACKGROUND

Solitary cystic lesion of the neck may often be the only initial presenting symptom for branchial cleft cysts and cystic metastases.

AIMS/OBJECTIVES

To analyse the malignancy rate detected in patients undergoing surgical treatment for lateral branchial cleft cyst.

MATERIAL AND METHODS

The records of all patients with surgical procedure code ENB40 (Excision of lateral branchial cleft cyst- or fistula) between 2003 and 2019 were reviewed. After excluding 150 patients, 436 patients were included for final analysis. Re-evaluation of the cytology including HPV-analysis was performed in those who had a malignant cyst.

RESULTS

Cystic metastases were demonstrated histologically after surgical excision in 13 patients (3%). In patients over 18 years of age, the prevalence of cystic metastasis regardless of the primary tumour type was 3.3%.

CONCLUSION AND SIGNIFICANCE

When the investigation protocol for solitary cystic lesions of the neck is followed, the negative predictive value for malignancy is 97%. All adult patients with a cytologic verified diagnosis of branchial cyst should be examined with HPV-analysis of the cystic sample before excision of the cyst. Failure of predicting a malignancy is often associated with cytology of poor cellularity which may be improved by more frequent use of ultrasound guided fine-needle aspiration cytology (FNAC).

Associations between EBV and CMV Seropositivity, Early Exposures, and Gut Microbiota in a Prospective Birth Cohort: A 10-Year Follow-up

Early-life infections with persistent Epstein-Barr virus (EBV) and cytomegalovirus (CMV) are delayed in affluent countries, probably due to alterations in early environmental exposures, such as maternal age, siblings, and day-care attendance. We have previously reported that the timing of EBV and CMV contraction is related both to allergic sensitization and changes in functional competence of immune cells, while the presence/absence of lactobacilli [Lactobacillus (L.) casei, L. paracasei, and L. rhamnosus] or Staphylococcus (S.) aureus in feces is related to the risk for allergy. Here, we used the same prospective longitudinal birth cohort of children to investigate early-life environmental exposures and their influence on EBV and CMV contraction over time. Since gut microbes also belong to this category of early exposures, we investigated their association with herpesvirus contraction. Our results show that these two viruses are acquired with different kinetics and that EBV and CMV seroprevalence at 10 years of age was 47 and 57%, respectively. We also observed that a delayed EBV or CMV infection was associated with older maternal age [time ratio (TR) 1.14, 95% confidence interval (CI) 1.07-1.21, P adj < 0.001 and TR 1.09, CI 1.03-1.16, P adj = 0.008, respectively]. Further, we present the novel finding that S. aureus colonization reduced the time to CMV acquisition (TR 0.21, CI 0.06-0.78, P adj = 0.02). Together, these findings suggest that there is a relationship between timing of herpesvirus acquisition and early-life immune modulating exposures, which interestingly also includes the early infant gut microbiota.

Thyroid epithelial cell proliferation in xenotransplanted human toxic nodular goitre is increased by Graves' IgG

Human toxic nodular goitre tissue was xenotransplanted to athymic mice. Transplant function was analysed as 18-h thyroid transplant uptake of iodide-125 at day 21 and again at 10 weeks after transplantation. Graves' IgG or IgG from healthy donors was given intraperitoneally daily day 22-35. Epithelial cell proliferation in thyroid tissue transplants from human toxic nodular goitre and from normal thyroid glands was analysed by continuous [3H]thymidine administration for 4 days between day 21 and 24 and for 12 days between day 21 and 33 in separate series given daily injections of Graves' IgG or normal IgG during the same period. After administration of Graves' IgG, the 18-h iodide-125 uptake by the toxic nodular tissue transplants was 7 times higher at 10 weeks than at 3 weeks. Control IgG gave a corresponding 1.6-fold increase. The fraction of labelled cells after [3H]thymidine incorporation was 18 and 56% in toxic nodular goitre transplants and 4 and 48% in normal thyroid tissue transplants after daily Graves' IgG administration for 4 and 12 days, respectively, but only 1.3% in both types of tissue transplants after administration of normal IgG. Graves' IgG therefore seems to be able to stimulate cell proliferation in toxic nodular goitre tissue.

Plasma membrane shedding and colloid vacuoles in hyperactive human thyroid tissue

The ultrastructural appearance of colloid vacuoles, considered to be a typical sign of hyperactivity in the human thyroid gland, was studied in human thyroid tissue transplanted to nude mice and in human thyroid tissue fixed directly after surgical removal in patients with thyrotoxicosis. Transplanted normal thyroid tissue and toxic diffuse goiter (TDG) tissue was fixed by vascular perfusion with glutaraldehyde 5 or 12 weeks after transplantation. Light microscopic quantification showed that daily injections for 2 weeks of a gamma globulin fraction of patient sera containing thyroid-stimulating immunoglobulins (TSI) greatly increased the number of colloid vacuoles in both types of transplants. The vacuoles were mainly located in the periphery of the follicle lumen, giving the colloid a scalloped appearance. Electron microscopy of TSI-exposed tissue revealed, in addition to colloid vacuoles, the presence of large amounts of membrane material in the follicle lumen. Only sparse amounts of intraluminal membrane material were present in controls. The colloid vacuoles were almost invariably associated with such membrane material, which lined the border between the vacuole and the surrounding colloid. The intraluminal material consisted of spherical and elongated formations, each structure limited by a triple-layered membrane and often containing a dense interior. The elongated structures were often of the same dimensions as microvilli. The apical surface of follicle cells in TSI-exposed tissue expressed numerous microvilli, of which many showed a similar dense interior as the intraluminal membrane structures. The intraluminal membranes frequently showed, like the apical plasma membrane of the follicle cells, a positive reaction for peroxidase. Organelles, such as mitochondria, lysosomes or rough endoplasmic reticulum, were not encountered among the intraluminal membrane structures. These observations indicate that the intraluminal membrane material is derived from the apical plasma membrane of the follicle cells, presumably by shedding of microvilli. A similar association between colloid vacuoles and membrane material was also found in thyroid tissue from patients with thyrotoxicosis fixed directly at operation. It is suggested that the presence of membrane material in the follicle lumen precipitates the formation of colloid vacuoles in hyperactive thyroid tissue. The possible involvement of intraluminal membrane material in the development of microsomal autoantibodies in Graves' disease, i.e. exposure and presentation of thyroid microsomal antigen (identical to thyroperoxidase) to the immune system, is discussed.

Effects of thyroid stimulating immunoglobulin on function and morphology of xenotransplanted toxic diffuse, toxic nodular and normal thyroid tissue

In order to examine the properties of human thyroid tissue, toxic diffuse goiter (TDG), toxic nodular goiter (TNG) and normal thyroid tissue were transplanted to nude mice. Starting 3 and 10 weeks after the transplantation the mice were given 14 daily injections of control serum or serum containing thyroid stimulating immunoglobulin (TSI). The uptake and release of 125I were repeatedly measured externally. The uptake and unstimulated release of 125I was lowest in TDG transplants, highest in TNG transplants, and intermediate in transplants of normal thyroid tissue. The findings were similar at both 3 and 10 weeks. Injections of TSI reduced the biological half-time of the tracer in TDG and normal transplants, but had no significant effect on TNG transplants. Light and electron microscopic studies showed that hyperplastic TDG tissue underwent involution after transplantation, whereas TNG and normal thyroid tissue remained unchanged. Injection of TSI reactivated TDG tissue; morphometry showed that the absolute and relative volumes of the follicle cells were more than doubled, with a corresponding decrease in the volume of the follicle lumen, and mitotic figures were common. Similar findings were seen in normal transplants, whereas the effect of TSI on TNG tissue was less pronounced. In summary, our observations show that serum from a patient with Graves' disease stimulated iodine release and induced follicle cell hyperplasia and probably also follicle cell multiplication in transplanted normal and TDG tissue, but had a lesser effect on TNG tissue.

Graves' IgG stimulates thyroid epithelial cell proliferation in xenotransplanted human toxic diffuse goitre

Human toxic diffuse goitre tissue was xenotransplanted to athymic mice. Transplant function was analyzed as 18 h [125I]thyroid transplant uptake at day 21 and at 10 weeks after transplantation. Graves' IgG or normal IgG was given ip daily day 22-35. Epithelial cell proliferation in the thyroid transplants was analyzed by continuous [3H]thymidine administration for 12 days between day 28 and 39 in a separate series given Graves' or normal IgG daily during the same period. The 18 h transplant uptake increased 12.8 times from 3 to 10 weeks in the Graves' IgG group but only 3.6 times in the controls (P less than 0.05). The fraction of labelled cells after [3H]thymidine incorporation was 51% +/- (SEM) after parallel Graves' IgG administration but only 2 +/- 0.3% (P less than 0.002) in the controls. The increased 10 weeks iodide uptake after Graves' IgG may be explained by an increased vascularisation or capillary maturation, by an increased individual cell sensitivity to stimulation or by an increased number of cells. Our results indicate that serum from patients with toxic diffuse goitre, i.e. Graves' IgG, contains a factor which promotes thyroid epithelial cell proliferation. Whether this is identical to TSI or is another IgG fraction remains to be shown.

Naturally occurring clones of cells with high intrinsic proliferation potential within the follicular epithelium of mouse thyroids

The proliferation pattern of some scattered clones of naturally occurring follicular cells with an exceedingly high intrinsic growth potential was investigated in the mouse thyroid gland. In particular, evidence was sought to demonstrate that the high propensity to replicate is a stable trait transmitted from the progenitor cells to their offspring. We hypothesize that these cell clones are at the origin of the multiple adenomas that invariably arise in chronically stimulated thyroid. Growth stimulation was induced either by hemithyroidectomy or by methimazole feeding. In a first series of experiments, involving hemithyroidectomized animals, [3H]thymidine was administered continuously for 3 weeks by means of osmotic minipumps, so that all cells entering the mitotic cycle during that time were labeled. Hemithyroidectomy led to a 3-fold increase of the fraction of labeled cells in the remaining lobe. The increase was prevented by thyroxine treatment in thyroid-stimulating hormone-suppressing doses. Autoradiographs of contiguous serial sections across whole follicles showed that roughly 75% of the labeled cells were clustered in groups of 3 or more, rather than being randomly distributed. In a second set of experiments, glands stimulated by methimazole-induced thyroid-stimulating hormone hypersecretion were pulse-labeled by a single i.p. injection of [3H]thymidine. Animals were sacrificed either 2 h or 3 weeks after the administration of the label. The thyroids were excised and the fate of labeled thyroid cells was analyzed autoradiographically. In the 2-h exposure, about 95% of all labeled follicular cells were single and the remaining 5% were in pairs. In contrast, about 50% of all labeled cells were clustered in groups of 3 to 12 cells 3 weeks after the pulse labeling. The number of silver grains per nucleus was compared to that of the identically exposed controls. The intensity of label per cell appeared to be decreased in proportion to the size of the labeled clusters, indicating that clusters had generated several subsequent generations of cells. The results support previously produced evidence that highly growth-prone cells naturally occur within the normal thyroid and demonstrate, in addition, that their high intrinsic growth rate is a stable, inheritable trait. Cells which replicate at a rate faster than that of the average epithelial cell have a tendency to overgrow during goitrogenesis. They may be at the very origin of the nodules and adenomas commonly found in experimentally produced and naturally occurring goiters.

Vascularization of normal human thyroid tissue transplanted to nude mice

The vascularization of normal human thyroid tissue transplanted to nude, athymic mice was examined by light, electron microscopy and autoradiography after continuous infusion of 3H-thymidine during 2, 4 and 6 days after transplantation. Labelled vascular sprouts were found in the surrounding host connective tissue after 2 days, in between peripheral follicles after 4 days and in central parts of the transplants after 6 days. The autoradiographic observations indicate that the sprouts originated from the surrounding host tissue. The amount of sprouts increased up to a maximum after 2 weeks of transplantation. At this time large interfollicular areas were occupied by sprouts. At later observations (3-5 weeks) sprouts occurred together with typical fenestrated capillaries. After 7 weeks all sprouts had differentiated into mature vessels. Our observations suggest that the transplanted thyroid tissue induces the formation of vascular sprouts in the surrounding host connective tissue. The sprouts then penetrate and vascularize the thyroid tissue.

Betablockers compared with antithyroid drugs as preoperative treatment in hyperthyroidism: drug tolerance, complications, and postoperative thyroid function

Subtotal thyroid resection or hemithyroidectomy was performed for hyperthyroidism on two groups of patients: 84 treated before surgery with antithyroid drugs and thyroxin and 111 given only beta-blocking agents before surgery. These two patient groups were compared with reference to preoperative medication, operation, immediate postoperative course, and late results, with follow-up for 3 to 7 years. The advantages of beta-blockers compared with conventional antithyroid medication were lack of adverse reactions, rapid effect of treatment, considerably shortened preoperative treatment time, and fewer outpatient visits, with consequent financial benefit. No disadvantages of beta-blockers were found except that 18% of the patients required additional propranolol in the immediate postoperative period. There were no surgical complications in either group other than a mild persistent hypocalcemia in two patients from the beta-blocked group. The serum thyrotropin levels during the first 6 postoperative months were significantly higher in the patients treated with antithyroid drugs. The frequency of postoperative thyroid dysfunction showed no intergroup difference during the observation period. Signs of hypofunction, necessitating thyroxin supplementation, were observed in 28.6% of patients in the antithyroid drug/thyroxin group and in 25.7% in the beta-blocker group. Toxic recurrence occurred in 1.8% of the group that received beta-blockers and in 1.2% of the other patients. The study demonstrated that beta-adrenoceptor blockade is a safe method for preoperative treatment in hyperthyroidism, with advantages for patients and regarding costs.

Ultrastructural morphology and evidence of iodide uptake and protein synthesis in normal human thyroid transplants in nude mice

Normal human thyroid tissue was xenotransplanted to athymic mice. Well preserved structural properties of the transplants were observed at both light and electron microscopical level. Analysis of the soluble proteins in the transplants by polyacrylamide gel electrophoresis showed that the major fractions were the 19S thyroglobulin, the 27S iodoprotein and a larger protein fraction. Protein synthesizing capacity of the transplants, as measured by in vivo 3H-leucine incorporation into the soluble transplants proteins was demonstrated. The observed 3H-leucine incorporation was in the same magnitude as that found in the original donor tissue at the time of transplantation. Four weeks after transplantation a significant 125I-iodide uptake (2.0%) was observed in the transplants. Corresponding value for the host thyroids was 6.6%. The biological half-time of the accumulated 125I-iodide in the transplants was reduced from 97 days to 38 days between 2 and 4 weeks after transplantation. The biological half-time in the host thyroid increased from 27 days to 32 days during the same period. This investigation shows that normal human thyroid tissue can be transplanted to nude mice with preserved tissue organisation and maintained cellular function.