Whole-organ Sections Research Articles

Surgical histoanatomy for adduction arytenopexy using injection laryngoplasty.

In order to improve a large posterior glottal gap and/or aspiration, injections of augmentation substances should not only be administered at the mid-membranous vocal fold in the thyroarytenoid muscle, but also at the cartilaginous portion of the vocal fold to make adduction arytenopexy possible. Ten adult human larynges were investigated using the whole-organ serial section technique. Vertical thickness of the posterior aspect of the thyroarytenoid muscle was relatively thin (3.4 ± 0.4 mm), especially in females (3.2 ± 0.3 mm). Consequently, care should be taken to ensure the correct depth of needle placement. If the needle is placed too deep, augmentation substances are injected into the lateral cricoarytenoid muscle, located beneath the thyroarytenoid muscle, or into the paraglottic space, located inferolateral to the thyroarytenoid muscle. The injection location and the amount of injected material should be modified based on the pathological conditions of the voice disorder and aspiration.

Local recurrence of squamous cell carcinoma of the head and neck after radio(chemo)therapy: Diagnostic performance of FDG-PET/MRI with diffusion-weighted sequences

PurposeTo determine the diagnostic performance of FDG-PET/MRI with diffusion-weighted imaging (FDG-PET/DWIMRI) for detection and local staging of head and neck squamous cell carcinoma (HNSCC) after radio(chemo)therapy.Materials and methodsThis was a prospective study that included 74 consecutive patients with previous radio(chemo)therapy for HNSCC and in whom tumour recurrence or radiation-induced complications were suspected clinically. The patients underwent hybrid PET/MRI examinations with morphological MRI, DWI and FDG-PET. Experienced readers blinded to clinical/histopathological data evaluated images according to established diagnostic criteria taking into account the complementarity of multiparametric information. The standard of reference was histopathology with whole-organ sections and follow-up ≥24 months. Statistical analysis considered data clustering.ResultsThe proof of diagnosis was histology in 46/74 (62.2%) patients and follow-up (mean ± SD = 34 ± 8 months) in 28/74 (37.8%). Thirty-eight patients had 43 HNSCCs and 46 patients (10 with and 36 without tumours) had 62 benign lesions/complications. Sensitivity, specificity, and positive and negative predictive value of PET/DWIMRI were 97.4%, 91.7%, 92.5% and 97.1% per patient, and 93.0%, 93.5%, 90.9%, and 95.1% per lesion, respectively. Agreement between imaging-based and pathological T-stage was excellent (kappa = 0.84, p < 0.001).ConclusionFDG-PET/DWIMRI yields excellent results for detection and T-classification of HNSCC after radio(chemo)therapy.Key points• FDG-PET/DWIMRI yields excellent results for the detection of post-radio(chemo)therapy HNSCC recurrence.• Prospective one-centre study showed excellent agreement between imaging-based and pathological T-stage.• 97.5% of positive concordant MRI, DWI and FDG-PET results correspond to recurrence.• 87% of discordant MRI, DWI and FDG-PET results correspond to benign lesions.• Multiparametric FDG-PET/DWIMRI facilitates planning of salvage surgery in the irradiated neck.

Assessment of the paraglottic space in supracricoid laryngectomy

EnAbstractBackgroundSupracricoid laryngectomy (SCL) is largely affected by invasion of the tumor into the paraglottic space.Aim of the workThe aim of this study was to histopathologically examine whether SCL provides adequate safety margins in terms of the paraglottic space or not.Patients and methodsA prospective study was carried out on 20 patients with advanced cancer larynx staged as T2b, T3 and cases with failed radiotherapy where SCL was performed, followed by whole-organ transverse sections of the specimens to evaluate the relation of the tumor to the paraglottic space.ResultsThe local success rate in this study was 90%; one case showed infiltrated surgical margins and the other showed local recurrence 6 months after the operation.ConclusionSCL allows for a safe enbloc resection of a malignant tumor in the larynx with complete resection of the paraglottic space. A safety margin of at least 4 mm is needed to eradicate the tumor as revealed by the whole-organ section technique.

Neuromuscular Basis for Ventricular Fold Function

We sought to examine the neuromuscular basis for ventricular fold function. The primary function of the ventricular folds is to assist in the regulation of intra-abdominal and intrathoracic pressure. They also influence phonation in the setting of vocal fold paralysis or ventricular dysphonia, or after partial laryngectomy. The neuromuscular basis of true vocal fold function has been well studied; however, its neuromuscular correlates in the ventricular folds are ambiguous. The literature is unclear as to whether ventricular fold contraction is passive or active. The musculature and innervation responsible for this action also have not been well defined. The aim of this study was to provide clarity in regard to these mechanisms. We examined a whole-organ section of a human larynx from a patient with unilateral vocal fold paralysis. The region of the ventricular folds was compared on both the paralyzed and normal sides. Electrophysiological examination was performed in a porcine model. The superior laryngeal nerve was stimulated, and recording electrodes in both ventricular folds measured the electrical activity. The recurrent laryngeal nerve was then severed, and the experiment was repeated. The histologic slides from the patient with unilateral vocal fold paralysis demonstrated atrophied ventricularis and thyroarytenoid muscles on the paralyzed side. On the unaffected side, these muscles were of normal size. The electrophysiological examination in the porcine model demonstrated findings consistent with innervation of the ventricularis muscle by the recurrent laryngeal nerve. An association of ventricularis muscle activity with ventricular fold contraction also was demonstrated. Ventricular fold adduction appears to be a result of ventricularis muscle contraction that is mediated by the recurrent laryngeal nerve.

Anatomical landmarks for endosonography of the larynx

A precise knowledge of anatomy is necessary to allow a correct interpretation of sonographic images when investigating a particular region of the body. The objective of the present study was to establish anatomical landmarks for endosonography of the larynx. In an experimental study, a total of 32 normal human larynges were examined endosonographically, and the classical landmarks were correlated to horizontal whole-organ sections of the scanned specimens. All laryngeal specimens showed a similar and reproducible sonoanatomy, which could be verified consistently on corresponding histological cross sections. Anatomical structures readily identified included the laryngeal framework, the vocal ligament, the vocal muscle, the ventricular fold, the preepiglottic and paraglottic space, and the epiglottis. Due to a reproducible sonoanatomy of the larynx, endosonography might be an interesting complementary tool in the diagnostic investigation of laryngeal lesions such as medium-sized tumors, cysts, laryngoceles, and stenoses.

Large Image Microscope Array for the Compilation of Multimodality Whole Organ Image Databases

Three-dimensional, structural and functional digital image databases have many applications in education, research, and clinical medicine. However, to date, apart from cryosectioning, there have been no reliable means to obtain whole-organ, spatially conserving histology. Our aim was to generate a system capable of acquiring high-resolution images, featuring microscopic detail that could still be spatially correlated to the whole organ. To fulfill these objectives required the construction of a system physically capable of creating very fine whole-organ sections and collecting high-magnification and resolution digital images. We therefore designed a large image microscope array (LIMA) to serially section and image entire unembedded organs while maintaining the structural integrity of the tissue. The LIMA consists of several integrated components: a novel large-blade vibrating microtome, a 1.3 megapixel peltier cooled charge-coupled device camera, a high-magnification microscope, and a three axis gantry above the microtome. A custom control program was developed to automate the entire sectioning and automated raster-scan imaging sequence. The system is capable of sectioning unembedded soft tissue down to a thickness of 40 microm at specimen dimensions of 200 x 300 mm to a total depth of 350 mm. The LIMA system has been tested on fixed lung from sheep and mice, resulting in large high-quality image data sets, with minimal distinguishable disturbance in the delicate alveolar structures.

A clinico-pathological study of laryngeal and hypopharyngeal carcinoma: Correlation of cord-arytenoid mobility with histopathologic involvement

This study evaluates the vocal cord and arytenoid mobility in relation to the tumoral involvement of the cricoarytenoid joint (CAJ), thyroarytenoid (TA) muscle, and posterior cricoarytenoid (PCA) muscle in whole-organ sections of total laryngectomy specimens. The study was prospectively carried out between 1998 and 2003 and involved 133 primary squamous cell carcinoma cases of larynx or pyriform sinus that were treated with total laryngectomy. Preoperative mobility of vocal cords and arytenoids were evaluated separately and correlated with histopathologic findings. In cases with fixed vocal cord CAJ, TA muscle, and PCA muscle were involved in 42.4%, 72.9%, and 27.1% of the cases, respectively, while in cases with fixed arytenoid these structures were affected in 40%, 66.3%, and 25.3% of the cases. Weight effect seemed to play a role in 60% and 50% of the cases of supraglottic and pyriform sinus carcinoma, respectively. Careful evaluation of the mobility of the cord arytenoid unit separately helps the surgeon to better understand the patterns of tumoral extension guiding for the appropriate surgery which should be undertaken.

Immunohistochemistry of whole-organ sections of advanced human laryngeal cancer

Whole-mount sections have been in the interest of laryngologists for long time. The aim of this study was to demonstrate the technical aspects of processing horizontal whole-mount sections of advanced laryngeal cancer specimens after total laryngectomy. Those sections may provide new insights in the biology of laryngeal cancer. Six excised human larynges were block-embedded in paraffine. Serial sections were obtained as thin as 9 mum. Sections were stained by Giemsa and standard immunohistochemistry protocols with commercial antibodies against Cytokeratine5/6, Ki-67, Topoisomerase IIalpha, and p53. Four high-power fields were selected randomly in each section of a surface grid and the percentage of positive tumor cells was noted for each antibody in the respective field. Morphometric surface maps of protein expression were generated for each parameter. The tissues remained intact without major artifacts. Specific characteristics of the tumors were identified after evaluation of the whole-mount sections. Staining of cytokeratine was homogenous, whereas nuclear markers showed a distinct heterogeneity in the respective staining patterns. By analyzation of color-coded fusion images the spatial expression of the respective antibodies could be visualized.

Multifocal nature of adenolymphoma of the parotid.

The multifocal nature of adenolymphoma of the parotid salivary gland was studied in 24 patients who underwent parotidectomy. Twenty-six resected specimens were examined by a step-serial whole-organ sectioning technique; multiple adenolymphoma was found in 13. The maximum number of synchronous tumours in any gland was four. Salivary epithelial elements were found embedded within lymph nodes in nine resected specimens. Synchronous or metachronous bilateral tumours were found in eight patients. The multifocal nature of adenolymphoma of the parotid gland is demonstrated.

Laryngeal involvement by differentiated thyroid carcinoma

Invasion of the larynx by differentiated thyroid gland carcinoma is uncommon but causes serious morbidity and mortality when present. The clinicopathologic characteristics of 5 patients in which a total laryngectomy had to be performed for differentiated thyroid carcinoma are analyzed. Special reference is paid to the histologic intralaryngeal tumor spread, which is evaluated on whole-organ section. All patients presented with hoarseness and/or dyspnea. Two patients are alive at 44 and 115 months. One patient died of intercurrent disease 2 months and 2 patients with disease 6 and 14 months after surgery. In all cases, intralaryngeal tumor spread was observed. Invasion of the larynx occurs by direct extension or by posterior tumor growth around the edge of the thyroid cartilage. In rare cases, differentiated thyroid carcinoma can widely infiltrate the larynx, making total laryngectomy unavoidable. The diagnosis of intralaryngeal tumor spread is done by imaging and endoscopy.

Recurrent pleomorphic adenoma of the parotid gland: a prospective histopathological and immunohistochemical study.

Histopathological characteristics and proliferation indices of recurrent pleomorphic adenoma were described in a series of 31 patients who were referred to the authors' clinic for revision surgery. Prospective series of 31 patients. Serial sections of surgical specimen using the whole-organ sectioning technique were carried out for light microscopic examination after total parotidectomy and periparotid fat resection. The nodules were examined with special reference to localization, amount, size, histological subtypes, capsular alterations, and the amount of nodule spilling. Expression of proliferation markers (Ki67/MIB-1) according to the size and histological subtypes of the nodules was also investigated. Most recurrences were multinodular, and the number of nodules was much higher than expected, ranging from 1 to 157. The myxoid subtype was predominant. Eighty percent of the patients exhibited widely distributed nodules also lying outside the scar. These nodules contained only a thin pseudocapsule and often lacked complete encapsulation. The majority of multinodular recurrences of parotid pleomorphic adenoma consisted of small nodules (less than 1 mm in diameter). Smaller nodules showed similar or higher levels of proliferative activity than larger nodules. The extended multifocal distribution of tumor recurrences after insufficient resection of pleomorphic adenoma (most often after enucleation) can explain a high incidence of further recurrences. Therefore, a total parotidectomy including removal of surrounding fat tissue seems to be appropriate for the initial treatment of recurrent pleomorphic adenoma.

Anatomy of the glottis and subglottis in the pediatric larynx

The morphological development of the human larynx during the first years of life has previously not been studied in detail and has mainly been described on a qualitative basis. This study seeks to provide detailed morphometric data on the regular anatomy of the vocal cords, the subglottic airway and the tracheal airway dimensions gained from plastinated whole organ serial sections of 43 infant larynges and to determine morphological changes with age. Such information may be useful for the understanding of pediatric airway disease or for laryngeal surgery in children. The larynges of 43 children aged 1 to 60 months were plastinated. Whole organ serial sections were obtained by cutting the resulting specimen with a diamond band saw. Morphometry of whole-organ sections was accomplished using a high resolution, computer-based image analyzer. The total length of the glottis, length of the cartilaginous and ligamentous glottis, subglottic cartilaginous cross-section, subglottic airway and tracheal airway were determined for each specimen. The subglottic airway increases considerably in size during the first 2 years of life (from 13 to 28 mm2 in the means). Further growth seems to follow a linear mode. The relative proportion of the mucosal lining of the subglottic airway decreases likewise. While it occupies approximately 50% of the subglottic cartilaginous cross-section during the first two years of age, its relative proportion decreases to some 30 to 40% between age three to five. Other than in adults, and comparable to most mammals, the cartilaginous glottis accounts for 60 to 75% of the vocal folds' length in children under two years of age. The anterior ligamentous part of the glottis outsizes its posterior cartilaginous portion during the third year of life. This study supplies detailed morphometric data on the growth and structure of the human larynx during the first years of life that have not been available to date. Previous studies on the anatomical configuration of the infant larynx have focused on the the perinatal larynx, the prepuberal and puberal larynx, and the development of collagen fibres in the developing larynx. The human larynx has undergone significant evolutionary adaptations. Among them are the descent of the larynx, the capability of vocal fold adjustment in length, tension and shape, and the prominent configuration of the membranous part of the vocal folds as opposed to the cartilaginous part. The infant larynx is not just a miniature of the adult organ. It shows differences in its position relative to the vertebrate column, in the composition of cartilages and soft tissues, and in environmental adaptation. The present study is the first to supply detailed morphometric data on the growth and structure of the human larynx during the first five years of life and on the morphological changes of the larynx during this period. From these data it seems that some of the adaption of the human larynx as opposed to other vertebrates are not fully developed at birth, but undergo postnatal maturation. The relative proportions of the cartilaginous and membranous parts of the vocal folds clearly demonstrate this maturation process: While the posterior "respiratory" glottis accounts for some sixty to 75% of the total glottic length in newborns, its relative proportion decreases throughout the first years of life and finally equals the proportions of the adult larynx. Other than in adults, and in accordance with the literature, no sexual dimorphism of the larynx could be detected in this series of infant larynges. Morphometric data on the growth and structure of the human vocal folds and the subglottic airway during childhood are presented. Plastinated whole organ serial sections were used in the study to show the infant laryngeal morphology. The study provides quantitative anatomical data of clinical interest that light up the anatomy of the pediatric airways.

Topographical anatomy and oncologic implications of the anterolateral surface of the arytenoid cartilage.

The normal topographic relationships of the anterolateral surface of the arytenoid cartilage (ALSAC) were reinvestigated with special regard to possible implications involving the extensions of local cancer. Serial plastinated whole-organ sections of 34 normal adult larynges were examined. A cartilaginous crest subdivided the ALSAC into a cranial triangular fossa and a caudal oblong fossa and provided attachment to the lateral fibers of the vocal cord. The thyroarytenoid muscle was mainly anchored within the oblong fossa, but a few lateral muscle fibers extended further cranial ward along the ALSAC. The triangular fossa was the area of fixation of the vestibular ligament and was filled with adipose tissue as well as mucous glands grouped together by strong collagenous fiber septa. These septa revealed a craniocaudal orientation medially and a horizontal anteroposterior orientation laterally. These findings suggest that the septa guide early local cancer extension parallel to their own arrangement, acting as barriers that cannot be easily crossed. Correspondingly, cranial and horizontal-lateral cancer spread along the ALSAC has been reported in the clinical literature.

Growth patterns of piriform sinus carcinomas.

Advances in functional surgery have encouraged many head and neck surgeons to treat piriform sinus carcinomas, whenever possible, by conservation surgery. An increased understanding of the histopathologic growth pattern and spread of piriform sinus carcionomas is needed to define criteria for appropriate application of voice preservation surgery. The purpose of this study was to analyze the patterns of tumor spread to laryngeal and parapharyngeal structures. A total of 42 specimens obtained by laryngopharyngectomy were subjected to a whole-organ section study. Carcinomas confined to the lateral wall tended to extend laterally beyond the thyroid ala and rarely infiltrated the intrinsic laryngeal muscles. As a result, conservation surgery could be possible in many cases, including T4 carcinomas. Carcinomas confined to the medial wall or occupying the whole piriform sinus tended to infiltrate laryngeal structures early, and hemilaryngeal fixation was observed in 61% of these cases; tumor spread to the contralateral side in 64%. The hemilarynx fixation was due to an invasion of intrinsic laryngeal muscles. An isolated perineural or cricoarytenoid joint involvement was never observed. For these tumors, conservation surgery would be inadequate in most cases, as they often present extensive laryngeal involvement with spread to the contralateral side.

Sheet plastination of the larynx for whole-organ histology.

Whole organ serial sections of the larynx are recognized to improve the assessment of laryngeal pathology. The human larynx with its complex anatomy of different types of tissue with their marked differences in hardness complicate the cutting process. The methods established are either very costly, time consuming and prone to artefacts, or sections are too thick for a histological work-up. Prior decalcification causes major shrinkage, thus morphometry is not feasible. We describe a technique of sheet plastination to produce whole-organ sections which allows a full-scale histological investigation without prior decalcification. Deep-frozen larynges are cut into 4-micron-thick sections using an ordinary slicing machine. Slices are dehydrated in acetone and plastinated in Biodur E50/E7/ AE10/E700. These specimens are cut into sections of about 80 microns thickness using a diamond-wire saw. An ultra-milling device reduces the section thickness down to about 10 microns. Surface staining of different kinds like Richardson, methylene blue or Paragon yields sufficient contrast for exact diagnosis. Deplastination and consecutive paraffin-like staining is possible, but results are not yet fully satisfying. Histological sheet plastination produces almost artefact- and shrinkage-free whole-organ sections in a period of about 1 week. The technique is useful for studies of micromorphometry or tumor spread. Theoretically, application of immunohistochemical staining methods seems to be possible. This might lead to mapping the proliferation activity of laryngeal cancer as it is presented on whole-organ sections.

Plastination of the larynx for whole-organ sectioning.

Whole-organ sectioning is an important technique for the assessment of laryngeal pathology. Since currently established methods require prior decalcification which causes morphological changes, the critical border area between cartilage and surrounding soft tissue cannot be investigated in the same specimen and morphometric studies are not possible. Plastination is a laboratory technique that has previously demonstrated its capacity to overcome these shortcomings. In so doing water and lipids are replaced by curable polymer within the laryngeal cells making decalcification unnecessary. In the present study, more than 50 human larynges were processed using block plastination (BP) and sheet plastination (SP). For BP the complete organ was plastinated as a whole and then cut into thin serial sections. For SP the fresh organ was sliced first and plastinated in a second step. Findings demonstrated that SP allowed for the production of whole-organ sections within a period of 1 week only. Section thicknesses were as thin as 15 mm using a diamond wire saw and an ultramilling device. Sectioning was possible in both coronary and horizontal planes. Following BP, specimens were cut in an industrial cutting machine to thicknesses of about 0.6 mm. Shrinkage of tissue was less than 10% for both methods. In all, SP was technically superior to routine paraffin histology, although cutting equipment is very expensive and delicate in handling. At present the technique of BP is the method of choice for macromorphometrical investigations on serial sections of the human larynx.

Borders and topographic relationships of the paraglottic space.

The precise topographic relationships of the paraglottic space (PGS) were investigated in serial plastinated or frozen whole-organ sections of 46 normal adult larynges. Laterally, the PGS was bordered by the thyroid cartilage. Superomedially, the PGS in some specimens was only separated from the periepiglottic space by a coherent collagenous fiber septum. The paraglottic adipose tissue extended between the caudal fibers of the thyroarytenoid muscle. Inferomedially, the PGS was bordered by the conus elasticus. The anteroinferior portion of the PGS extended beyond the larynx beneath the inferior rim of the thyroid cartilage. Posteroinferiorly, the paraglottic adipose tissue extended towards the cricoarytenoid joint. Dorsally, the PGS was bordered by the mucosal lining of the piriform sinus. Due to the intimate topographic and histologic relationships present, cancer involving the PGS may rapidly infiltrate all adjacent anatomic structures.

Morphometry of the larynx in horizontal sections

Until recently, only few studies on laryngeal morphometry in the horizontal plane, which used unreliable techniques, have been reported. The established methods of whole-organ serial sectioning of the larynx serve the purpose of histological investigation very well. Because they cause major tissue shrinkage, these techniques are not useful for morphometry. Nevertheless, normal data of laryngeal horizontal anatomy are of great surgical and diagnostic interest. Data on endolaryngeal angles, airway lumina, and the thickness of parts of the laryngeal skeleton can be helpful in the planning of endolaryngeal surgical intervention or the transcutaneous placement of electrodes for laryngeal electromyography. The aim of this study was to establish a method for the production of whole-organ serial sections that allows for the collection of exact and reliable morphometrical data. A total of 20 fresh human cadaver larynges were investigated in this study. Nineteen measurements on three different planes were obtained in each larynx. The larynges were shock-frosted using liquid propane and nitrogen and then cut with a slicing machine. Measurements were obtained using a computer-aided analyzing system. The collected data give an exact and extensive description of the morphometrics of laryngeal structures such as thyroid and cricoid cartilage, arytenoid cartilages, vocal cords, and endolaryngeal airways at different section levels. This study is the first to provide detailed anthropometric data on whole-organ sections of the larynx following a new method. This technique of using serial sections of the investigated specimen avoids artifacts caused by tissue fixation. Thus, it may be considered being particularly suited to the conduction of anthropometric studies on human larynges.

Laryngeal reconstruction following vertical partial laryngectomy.

Laryngeal reconstruction following vertical partial laryngectomy (VPL) with arytenoidectomy was studied in 30 dogs. Variations of a superiorly based thyroid cartilage flap (TCF) were used for reconstruction. In addition, sternohyoid muscle reconstruction and endolaryngeal muscle coverage were studied. Larynges were recovered after a 6-month period in 28 surviving dogs and were analyzed by endoscopic photographs and axial whole-organ sections. Endoscopic assessment (n = 18) demonstrated good results for arytenoid replacement (100%), pseudocord position (94%), pseudocord development (94%), and airway patency (100%). Arytenoid replacement was judged as completely (78%) or partially (22%) replaced. This was accomplished by a pseudocord extending to the cricoid in the horizontal plane. Pseudocord position was judged as normal (83%) or paramedian (11%), with the remainder lateralized (6%). Pseudocord development was judged as complete (72%) or partial (22%), with the remainder poor (6%). Reviewing both endoscopic photographs and gross sections (n = 28), airways were all normal without laryngeal or tracheal stenosis. Histologic assessment (n = 24) also demonstrated good results for arytenoid replacement (79%), pseudocord position (87%), and TCF survival in the glottic plane (79%). Arytenoid replacement was judged as complete (62%) or partial (17%), with the remainder poor (21%). Pseudocord position was judged as normal (50%) or paramedian (37%), with the remainder lateralized (13%). TCF survival was judged as total (63%) or partial (16%). Although not present in the glottic plane in the remaining cases (21%), a portion of the TCF was always present in the supraglottic region. The TCF was largely replaced by bone in the region of the pseudocord, and was covered by nonkeratinizing stratified squamous epithelium and a thick fibrous layer. Breakdown over the TCF was infrequent, with a small focus of granulation tissue over cartilage present in 1 (4%) of 24 cases. Clinically insignificant granulation tissue was present in a total of 6 (25%) cases. In the other 5 cases, this was over muscle or over permanent sutures. Focal cartilage necrosis was present in 2 (8%) of 24 cases, and was localized, self limiting, and deep to the endolaryngeal surface. When the TCF failed to survive histologically, poorer results for arytenoid replacement and pseudocord position generally resulted. However, this apparent difference was not statistically significant due to small sample sizes and variability in results. Other factors that may have kept this difference from becoming larger were thought to be contraction of th e normal cord towards the operated side with fore-shortening of the glottis, and medial rotation and ossification of the posterior thyroid ala remnant.(ABSTRACT TRUNCATED AT 400 WORDS)

Computed tomography of primary subglottic cancer: clinical importance of typical spread pattern.

The spread pattern of 14 cases of primary subglottic cancer, as seen on computed tomography (CT), is analyzed. Cricoid cartilage invasion was present in nine cases. Tracheal invasion was definite in four cases and questionable in three. Extralaryngeal soft tissue spread was present in nine cases; all but one had cartilage destruction. The patterns of spread seen accurately reflect reports in previous whole-organ section studies, and suggest that the elastic cone has a primary role in directing the spread of tumor. Anticipating spread to areas described above with CT and/or magnetic resonance imaging (MRI) can be used to try to improve treatment planning and perhaps outcome by: (1) avoiding placement of urgent tracheostomies close to the tumor; (2) helping to modify standard surgical approaches by suggesting lower-than-usual tracheostomies, or more extensive-than-usual thyroid gland resection; and (3) avoiding delay in diagnosis by strongly suggesting rebiopsy when imaging indicates a tumor is present, and initial endoscopy and biopsy cannot confirm the imaging findings.