Significance and management of thyroid lesions in lymph nodes as an incidental finding during neck dissection.

BACKGROUND: The incidental discovery of thyroid lesions in lymph nodes during a lymph node dissection performed for a separate primary head and neck tumor is an unusual clinical entity. Its discovery has led to controversy regarding its significance and management. METHODS: We identified five patients over the years 1991-1999 with this finding. All five patients were subsequently treated with a total thyroidectomy and a level VI lymph node dissection. RESULTS: Pathological examination revealed three papillary carcinomas and level VI lymph node metastases in the two patients who had carcinoma in their thyroid glands. All five patients are presently free of their primary and thyroid disease on follow-up examinations. CONCLUSIONS: These patients should be addressed with additional work-up and surgery if metastatic thyroid cancer is documented in the lymph node. We offer a diagnostic algorithm that may aid in further work-up and treatment in these unusual cases.

Lymphatic malformation: predictive factors for recurrence.

OBJECTIVE: Although lymphatic malformations are often found to be well circumscribed when surgery is undertaken in early childhood, complete surgical excision can be difficult when the lesion is infiltrative. This study retrospectively evaluates these patients in an attempt to identify prognostic factors that may predict recurrence. STUDY DESIGN AND SETTING: A retrospective chart review was conducted covering the years 1991 to 1998. Seventeen patients were identified having undergone 32 surgical resections of tumors described as lymphatic malformations. Data abstracted from the charts included the site of the lesion, surgical and histologic assessment of encapsulation, and status at follow-up examination. RESULTS: Six of 17 patients developed a recurrence after surgery. Correlation between recurrence and histologic or operative impressions of encapsulation was significant by chi(2) analysis (P<0.01). CONCLUSION: On the basis of the findings of this case series, lymphatic malformations that are found to be nonencapsulated and infiltrative by intraoperative or histologic assessment are more likely to recur.

Nasal obstruction: an alternative to ostiomeatal complex dysfunction in sinus disease.

OBJECTIVES: Ostial patency is thought to be essential to the function of the maxillary sinus. Ostiomeatal complex dysfunction has been implicated as a major factor in the pathogenesis of sinus disease. However, recent work in our laboratory has indicated that other factors may also contribute to this process. The objective of this study was to determine the effect of nasal obstruction in maxillary sinus gas composition, independent of its effect on ostial ventilation. STUDY DESIGN: Prospective controlled animal study. METHOD: Independent models of nasal obstruction and ostial occlusion in contralateral sinuses were established. Ipsilateral models of nasal obstruction and ostial occlusion were also created. Gas samples from each of the manipulated sinuses were analyzed on a gas chromatogram and compared. RESULTS: Results revealed a dramatic and highly significant increase in antral carbon dioxide (CO2) concentrations in the sinuses ipsilateral to either an occluded ostium or an obstructed nostril, compared with the controls. These effects on CO2 concentrations were additive when ipsilateral nasal obstruction and ostial occlusion were created. Furthermore, the effect of nasal obstruction in modulation of antral CO2 levels was found to be beyond its effect on hypoventilation of the sinus and to be independent of ostial functional status. CONCLUSIONS: We have established independent models of nasal obstruction and ostial occlusion in the same animal. Our findings suggest that ostiomeatal complex dysfunction might not be the sole underlying factor in the pathogenesis of sinus disease in all individuals. Integrity of nasal airflow seems to have a significant effect on the maintenance of the aerobic antral environment, essential to the maintenance of normal sinus function. Modulation of maxillary sinus gas composition by nasal airflow, independent of ostial patency, may be explained by the possible presence of flow-sensitive receptors in the upper respiratory tract mucosa. Work to identify such receptors is currently in progress.

Use of the peritracheal fold in the dog tracheal transplantation model.

OBJECTIVE: To investigate the technical aspects of the canine model of human tracheal transplantation for potential application to reconstruction of extremely long tracheal defects (> 10 cm). DESIGN: In phase 1, long tracheal segments were skeletonized and pedicled with the thyroid glands, cranial thyroid arteries and veins, and internal jugular vein branches. The segments were elevated completely, attached to the vascular pedicle only, and replaced with primary tracheal anastomoses. In phase 2, long segments were elevated along with a diffuse soft tissue "blanket" that envelops the trachea and thyroid glands. Because this study was designed to primarily address, in situ, tracheal perfusion territories of a cranially located vascular pedicle, microvascular anastomoses were not conducted. SUBJECTS: Two small-bodied beagles (10-15 kg) and 5 large-bodied mixed-breed dogs (20-30 kg) were humanely killed 2 to 41 days after surgery, and anatomic and histological analyses were conducted. RESULTS: Unlike that of humans, the thyroid gland complex of dogs is not intimately associated with the trachea but is conjoined with a peritracheal soft tissue "fold." Within this fold, blood is transmitted to the trachea via a diffuse, segmental vascular plexus. In phase 1, pronounced tracheal necrosis occurred within 2 to 5 days. In phase 2, extremely long tracheal segments (10-12 cm), based only on a cranially located pedicle, were still viable at 2 to 6 weeks. CONCLUSIONS: Preservation of the "peritracheal fold" in the dog model of tracheal transplantation is critical to the onset and maintenance of vascular perfusion in a long tracheal segment. Furthermore, the use of large-bodied dogs is necessary to provide for a usable venous efflux component.