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Biomedical subjects

Kenneth O Devaney

Publications and source records attributed to Kenneth O Devaney.

At least 19 recordsLinked to original sources
PubMed2006

Neuroendocrine neoplasms of the larynx: advances in identification, understanding, and management.

While 85-90% of laryngeal malignancies prove to be squamous carcinomas, the second most common tumour type found in the laryngeal region will prove to be a member of the family of neuroendocrine tumours. Laryngeal carcinoid tumours have a capacity for metastasis, and so are more aggressive tumours than their light microscopic features might imply--5-year survival rates are in the vicinity of 50%. Laryngeal atypical carcinoid tumours are lesions with a well-recognized capacity for local recurrence as well as metastasis, with a 5-year survival of just under 50%. Laryngeal small cell neuroendocrine carcinomas are particularly aggressive tumours, with a 5-year survival of no more than 5-10%. Laryngeal paragangliomas are lesions without any real capacity for metastasizing. Surgical excision is the mainstay of treatment of carcinoid tumours, atypical carcinoid tumours, and paragangliomas. Small cell neuroendocrine carcinomas are chiefly treated by way of radiation and chemotherapy; the role of adjuvant therapy in the treatment of atypical carcinoid tumours remains to be established.

Carcinoid Tumor↗
PubMed2006

Importance of molecular analysis in detecting cervical lymph node metastasis in head and neck squamous cell carcinoma.

BACKGROUND: Because of the impact of nodal status on treatment and survival in squamous cell carcinoma of the head and neck, accurate staging of cervical lymph nodes is critical. This article explores the value of molecular analyses in the detection of cervical lymph node metastasis. METHODS: A review of the literature was carried out and combined with our own experience regarding the role of molecular analyses in detecting cervical lymph node metastasis. RESULTS: Few studies have demonstrated the diagnostic and prognostic relevance of molecular analysis in detecting tumor cells in lymph nodes. Nodal staging was improved by the use of molecular techniques; when compared with histopathologic examination, however, the small sample size of these studies did not allow definitive conclusions. CONCLUSIONS: Molecular analysis is exquisitely sensitive in detecting very small cancer deposits within lymph nodes. It provides an oncologic basis that may be used to guide therapy and influence outcomes. It should be recommended for diagnostic use in controlled studies of patients without evidence of lymph node metastasis on routine hematoxylin-eosin-stained sections. The clinical significance of these types of metastases, however, must be determined with carefully designed and controlled prospective clinical trials.

Biomarkers, Tumor↗
PubMed2006

Molecular diagnostic methods in the diagnosis and follow-up of well-differentiated thyroid carcinoma.

Thyroid cancers are the most common endocrine malignancies and are being diagnosed with increased frequency in modern clinical practice. Among other diagnostic modalities, fine-needle aspiration (FNA) biopsy of clinically suspicious thyroid nodules is becoming increasingly popular. Preliminary investigations have suggested that molecular diagnostic assays using tumor-specific markers may improve the sensitivity and accuracy of FNA and so may be expected to reduce the frequency of open surgical procedures by identifying those patients with demonstrably benign lesions who do not require definitive surgical excision of their lesions for diagnosis. At the same time, thyroid-specific mRNA assays (especially thyroglobulin mRNA testing) have been used by investigators in the postoperative follow-up of patients with thyroid cancer as a potential means of detecting tumor recurrence in the peripheral blood. Although these studies have not all reported unqualified successes--indeed, some problems based on both technical and biologic limitations have been identified-these assays still hold out the possibility that potentially important new advances in the management of patients with well-differentiated thyroid cancer may be offered by these and other molecular diagnostic methods.

Biomarkers, Tumor↗
PubMed2006

Sentinel node biopsy and head and neck tumors--where do we stand today?

BACKGROUND: Sentinel lymph node sampling may be studied profitably in series of patients with 1 tumor type, such as breast carcinoma, in 1 anatomic locale. The present work analyzes the efficacy of sentinel node sampling in a pathologically diverse group of lesions from an anatomically diverse region such as the head and neck; however, there are risks conflating the findings in different tumors with radically different behaviors, in the process producing muddled data. This report reviews the head and neck experience with sentinel sampling and concludes that certain tumor types that have a known propensity for aggressive behavior are the best candidates for trials employing sentinel node sampling; candidates include many cutaneous melanomas of the head and neck, oropharyngeal squamous carcinomas, and selected thyroid carcinomas. Despite the growing popularity of sentinel node sampling in a variety of regions of the body, however, at this juncture this technique remains an investigational procedure, pending demonstration of a tangible improvement in patient outcome through its use. It is recommended that studies of the efficacy of this technique strive, whenever possible, to segregate results of different tumor types in different head and neck locales from one another so as to produce more focused findings for discrete types of malignancies, and not group together tumor types that may in reality exhibit different biological behaviors.

Head and Neck Neoplasms↗
PubMed2006

Primary carcinoid tumor of the middle ear: a potentially metastasizing tumor.

The concept of a carcinoid tumor in the gastrointestinal tract and lung is well established; less often, patients develop carcinoid tumors in the head and neck region. One particularly uncommon site of origin of carcinoid tumors in the head and neck area is the middle ear. Middle ear carcinoids have previously been approached as benign entities, lacking any capacity for metastasizing. A critical review of the literature, however, disclosed a small number of cases in which middle ear carcinoid tumors have given rise to regional (cervical node) metastases. This in turn suggests that, as is the case with pulmonary carcinoid tumors, middle ear carcinoids should be thought of as low-grade malignancies which, while relatively slow-growing, nevertheless possess a limited capacity for spreading to regional lymph nodes. To date, distant metastases have not been associated with middle ear carcinoid tumors.

Biopsy, Needle↗
PubMed2005

New molecular diagnostic methods in head and neck cancer.

Initial cancer evaluation includes assessment of histologic appearance, tumor grading, assessment of lymph node status, and presence of metastasis. However, traditional diagnostic methods such as histopathology and radiology are not sensitive enough to detect small numbers of cancer cells and are limited in their ability to predict response to treatment. Recently, there has been considerable progress in molecular diagnostics in these areas. Using molecular-based technologies, it is now possible to detect cancer early in asymptomatic individuals, identify minimal residual disease at histopathologic normal surgical margins, more precisely assess tumor burden in cancer patients, and more accurately assess the prognosis of the patients. Examples of these applications in the evaluation of head and neck cancer are reviewed here. However, despite the great promise of these new molecular approaches for cancer detection, much of the current technology limits their implementation into routine clinical use.

Biomarkers, Tumor↗
PubMed2005

Idiopathic midline destructive disease: fact or fiction.

The differential diagnosis of a progressive destructive lesion of the midface and upper airway region includes both neoplastic and non-neoplastic entities; of these, the majority of cases prove to be either Wegener's granulomatosis or lymphoma. Historically, these sorts of necrotizing midfacial lesions were diagnosed clinically, and as a consequence a variety of overlapping categories of disease sprang up. As pathologic examination of biopsy material became both more widespread and (particularly in the last several years) more sophisticated, many lesions previously thought to be of mysterious origins have proven to be examples of lymphoma (in particular, sinonasal natural killer cell or T cell [NK/T] lymphomas). At present, the evaluation of a patient with a progressive destructive process involving the midface region should include imaging studies (to delineate the extent of disease) as well as biopsy (with sampling of lesional tissue for application of sophisticated testing--including immunohistochemical studies, flow cytometry, or molecular studies as necessary--to exclude the possibility of a NK/T cell lymphoma). There remain occasional patients whose necrotizing midfacial lesions continue to be difficult to classify despite the application of extensive testing; such patients are sometimes described as suffering from the nebulous entity of "idiopathic midline destructive disease". While it remains to be seen whether such patients will ultimately be assigned to other diagnostic groups (as, for example, occult toxic injuries--as in the case of cocaine abusers who are not forthcoming with regard to their drug usage), it seems likely that "idiopathic midline destructive disease" is a diagnostic term of questionable validity which should be used only with extreme reticence in modern practice.

Diagnosis, Differential↗
PubMed2005

Vocal process granuloma of the larynx-recognition, differential diagnosis and treatment.

The vocal process granuloma is a nonneoplastic lesion that most often develops in the vicinity of the posterior vocal cords, adjacent to the vocal process. It may be an ulcerated region of the cord, or it may manifest as a nodular polypoid lesion. Causative factors include gastroesophageal reflux, intubation trauma, and vocal abuse. This lesion may be mistaken on clinical or pathologic grounds for carcinoma, although thorough microscopic examination usually permits a correct diagnosis. Despite its name, vocal process granuloma is not a true granulomatous process in a pathologic sense (inasmuch as it lacks aggregates of mononuclear and multinucleated histiocytes)-rather, it is a reactive/reparative process, in which an intact or ulcerated squamous epithelium is underlaid by granulation tissue or fibrosis. Treatment of vocal process granuloma centers around conservative voice therapy, coupled with treatment of any underlying inciting cause (such as gastroesophageal reflux). While it may recur locally (particularly if the original inciting cause persists), vocal process granuloma has no premalignant potential.

Diagnosis, Differential↗
PubMed2005

Tumours of the external ear and temporal bone.

Symptoms such as hearing impairment, tinnitus, or a disturbance in sense of balance can generally be attributed to non-neoplastic causes, such as otitis media, otosclerosis, or trauma. Less commonly, auricular signs and symptoms are the result of non-neoplastic and neoplastic space-occupying lesions. The external ear can be the site of development of squamous carcinomas and basal-cell carcinomas; the middle ear and inner ear can host metastatic deposits, and primary squamous carcinomas and adenocarcinomas. Most auricular malignant diseases occur in adulthood; only the rhabdomyosarcomas of the middle ear arise in children. Most malignant diseases of the auricular apparatus are treated by a combination of surgery (commonly including radical excision of temporal bone), radiotherapy, and chemotherapy.

Combined Modality Therapy↗
PubMed2005

Teratoma of the middle ear: a real entity or a non-entity?

Space-occupying lesions of the middle ear range from wholly benign developmental anomalies to highly virulent and aggressive malignancies. Amongst the benign entities classed with the family of developmental anomalies, the middle ear choristoma is well known. But what of the middle ear teratoma? Recent reports suggest that, while rare, teratomas of the middle ear do exist. Middle ear teratomas are defined as tumors consisting of benign tissues derived from all three embryologic layers: endoderm, mesoderm and ectoderm. They are lesions of the neonatal period and early infancy. While complete surgical excision will be curative, a thorough histologic examination of the specimen is recommended to exclude the possibility of immature and/or frankly malignant elements being admixed with the benign teratomatous elements.

Ear Neoplasms↗
PubMed2005

Merkel cell carcinoma of the auricle.

Merkel cell carcinoma (MCC) is an uncommon cutaneous neoplasm which arises in adults with a peak incidence in the sixth and seventh decades. MCC most often arises in the head and neck area and extremities. Among head and neck primary sites, auricular MCC has proven to be rare and only 20 cases have been reported in the literature. Auricular MCC follows the same aggressive course as has been documented for MCC arising elsewhere: the tumor has a propensity for recurring locally and metastasizing to regional lymph nodes and distant sites. Location of MCC in the auricular regions does not appear to confer any survival advantage compared with MCC arising elsewhere. The mainstay of treatment is surgery, with attempts at complete surgical excision being of paramount importance. What role regional node dissection, radiation therapy and chemotherapy may play in the standard treatment of auricular MCC remains to be clearly established.

Adolescent↗
PubMed2005

Malignant melanoma of the auricle.

Malignant melanomas are found in a variety of locations, ranging from sun-exposed skin to the nasal cavity and paranasal sinuses. Melanomas arising in the head and neck region comprise some 20% of all melanomas; of these, 7-15% occur in the vicinity of the external ear (most often on the helix). Auricular melanomas, like those arising elsewhere, are rare in childhood and are most often first diagnosed in men in their 50s. Melanomas of the external ear may present as flat pigmented lesions or as raised mass lesions; amelanotic (non-pigmented) variants exist as well. Auricular melanomas are frequently recognized pathologically as either superficial spreading melanomas or nodular melanomas. These tumors are aggressive, with a propensity for spreading to both regional lymph nodes and distant sites. Key pathologic prognostic features of auricular melanomas include the histological subtype, tumor thickness, level of invasion and presence of ulceration. Therapy includes both aggressive surgical attempts at excision in combination with sentinel node sampling in some instances and perhaps, adjuvant therapy as well. This is a tumor which is often overlooked until late in its course, with tragic consequences; vigilance and aggressive attempts at identifying these tumors at earlier stages are strongly advocated.

Biomarkers, Tumor↗
PubMed2004

Paragangliomas of the head and neck.

Paragangliomas are neuroendocrine tumors derived from the extra-adrenal paraganglia of the autonomic nervous system. Within the head and neck, they are generally defined and named according to their site of origin, and may be found frequently neighboring vascular structures. Physiologic activity is rare in these neoplasms and they may exhibit patterns of inheritance which predispose their occurrence in families, often with multicentricity. These tumors generally exhibit a slow rate of growth, most often presenting asymptomatically as a space occupying mass lesion noted clinically or radiographically. The most common paraganglioma of the head and neck is the carotid body tumor followed by the jugulo-tympanic and vagal varieties. Other rare sites where this tumor may occur include; the larynx, sinonasal chambers and orbit. Diagnosis is generally made through a combination of clinical findings and radiographic studies. Magnetic resonance represents the most important imaging modality for the evaluation and characterization of suspected head and neck paraganglioma. Definitive management for these lesions should be carefully considered in relation to both tumor and patient-oriented factors, especially in regard to the potential morbidity of treatment. Surgery and radiation therapy represent the main treatment modalities for paraganglioma. The selection of treatment depends on the size, location, and biologic activity of the tumor as well as the overall fitness of the patient. Although radiotherapy may be effective in arresting growth of these tumors, rarely is the neoplasm eliminated without surgical resection. Surgery may be associated with significant morbidity, primarily as a consequence of incurring major cranial nerve injury. Patient selection (relative to age and medical condition) should be carefully considered prior to recommending aggressive surgery for paragangliomas of head and neck, especially in those patients at risk for disabling surgical morbidity.

Carotid Body Tumor↗
PubMed2004

Merkel cell carcinoma of the head and neck.

Merkel cell carcinoma (MCC) is a rare neuroendocrine neoplasm of the skin. The tumor most frequently affects elderly patients, with a preference for the head and neck. Incidence rates increase with sun exposure and after immunosuppression and organ transplantation. A significant proportion of MCC have been reported to occur in intimate association with malignant epithelial neoplasms. The genetic mechanisms underlying the development and tumor progression of MCC are poorly understood, sharing pathogenetic mechanisms with other neoplasms of neural crest derivation. MCC has a propensity for spreading to regional lymph nodes, either at presentation or as a first site of relapse. Sentinel lymph node positivity is helpful in predicting the risk of recurrence or metastasis in patients with MCC. Complete surgical resection is the mainstay of treatment of the primary tumor. Tumor resections are recommended to include a 2-3-cm tumor-free margin around the primary lesion when possible, but this is often difficult to achieve in the head and neck, where Mohs micrographic surgery has proved to be effective. The role of adjuvant radiation therapy is controversial. The role of adjuvant chemotherapy in diminishing the risk of subsequent systemic recurrence in patients with positive nodes remains undefined. Overall response rates to combination chemotherapy for surgically unresectable distant metastatic disease are generally high, although responses are transient. Overall survival of head and neck MCC at 5 years postoperatively ranks between 40% and 68%. MCC has a high incidence of locoregional recurrences, but even after a locoregional failure, a substantial proportion of patients achieve long-term disease-free survival. Finally, factors generally associated with survival are the stage of disease at presentation, distant recurrence usually being the most adverse predictor of survival.

Carcinoma, Merkel Cell↗