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Biomedical subjects

B A Sebek

Publications and source records attributed to B A Sebek.

At least 19 recordsLinked to original sources
PubMed1990

Inverted papillomas and associated squamous cell carcinomas.

Inverted papillomas of the nose and paranasal sinuses are found to be associated with squamous cell carcinomas in a small percentage of cases. The records of forty-six patients treated for inverted papillomas in these areas over a 10-year period were reviewed. Eleven patients (24%) were found to have squamous cell carcinoma, and one carcinoma in situ, in relationship to the inverted papillomas. This is a much higher percentage than generally reported. Four of these patients were found to have inverted papillomas coincidentally in surgical specimens resected for squamous cell carcinoma. Patients with squamous cell carcinoma were found to be in older age groups, were more likely to manifest epistaxis than the more common unilateral nasal obstructive symptoms, and had less time between the onset of symptoms and presentation than those with inverted papillomas alone. The clinical presentation, treatment, and outcome of inverted papillomas and squamous cell carcinomas in association with inverted papillomas are discussed.

Adult↗
PubMed1990

Primary squamous cell carcinoma of the parotid gland.

Primary squamous cell carcinoma of the parotid gland is an uncommon malignancy. It can be diagnosed only after squamous cell carcinoma metastatic to the parotid gland has been excluded. Histologic evaluation must differentiate primary squamous cell carcinoma from high-grade mucoepidermoid carcinoma or adenocarcinoma. Retrospective review of parotid gland neoplasms seen in the Department of Otolaryngology and Communicative Disorders between 1972 and 1987 identified eight cases for an incidence of 1.8%. The majority of these patients had advanced disease and were treated with both surgery and radiation therapy. Fifty percent of the cases demonstrated no evidence of disease at an average follow-up of 29 months.

Adult↗
PubMed1989

Mucosal regeneration of the maxillary sinus after surgery.

The postsurgical effects of the removal of the maxillary sinus mucosa were studied in an animal model. Ten rabbits underwent Caldwell-Luc procedures with the removal of all the maxillary sinus mucosa from one sinus, while the other sinus in each animal was used as a control. After allowing time for postsurgical healing, animals were examined for mucociliary transport and sections for histologic examination were obtained. Respiratory ciliated epithelium was present in seven of the postsurgical sinuses. Marked increases in acute and chronic inflammation, granulation, fibrosis, and ulcerations were noted.

Animals↗
PubMed1986

The rotary door myocutaneous flap. A reliable technique for laryngotracheal reconstruction.

We examined the possible uses of the "rotary door" sternohyoid myocutaneous flap (RDF) in laryngotracheal reconstruction. This well-vascularized myocutaneous flap, when rotated axially, can replace or widen the anterolateral walls of the airway. It provides a large epithelial surface, together with bulky structural support. The flap is readily available within the immediate surgical field and can replace large defects in the airway, from the level of the glottis to the cervical trachea. After extensive structural and soft-tissue loss of the larynx and trachea were produced to simulate commonly encountered traumatic and postsurgical stenotic conditions, the RDF was employed in 23 dogs in a single-stage laryngotracheal reconstruction. A stable, widely patent airway was achieved. The dogs were followed up for periods varying from three to six months. No complications or secondary stenoses were encountered. Photographic, radiologic, and endoscopic examinations demonstrated the viability and usefulness of this newly described flap. Long-term tracheostomy was used so that intraluminal stents and cannulas could be avoided. Histopathologic studies confirmed the integration of the RDF into the framework of the larynx and trachea. Application of this technique in cases of tumors, trauma, and stenosis of the airway is suggested.

Airway Resistance↗
PubMed1985

The relationship between fistulas in Crohn's disease and associated carcinoma. Report of four cases and review of the literature.

Patients with carcinoma involving chronic fistulizing Crohn's disease may have developed the malignancy due to chronic epithelial irritation at either end of the fistula tract. Alternatively, the carcinoma may be the cause of the fistula. Examples of each type of relationship are presented in the reports of four patients from our institution and supported by a review of the literature. The diagnoses of such carcinomas are often delayed due to lack of specificity of symptoms and signs. A high index of suspicion and regular surveillance of high-risk patients are recommended.

Abdominal Muscles↗
PubMed1985

Histologic changes in skin implanted into the larynx and trachea by myocutaneous flap reconstruction.

Skin is the tissue most readily available for relining the walls of the reconstructed larynx or trachea. Its use has been condemned in the past because of potential contracture, complications have occurred when free, split-thickness grafts were used. We studied the changes that develop within skin that is transferred into the lumen of the airway as part of a vascularized sternohyoid myocutaneous flap. Twenty-one dogs underwent reconstruction of laryngotracheal defects by a vascularized myocutaneous flap. The closely shaved and chemically depilated skin included in this reconstruction was ultimately found to be well healed to the adjacent mucosa. Flaps as large as 8 cm2 survived with no evidence of scaling, crusting, or contracture. The cutaneous appendages in the flaps were compared with those found in adjacent skin near the donor site. After proper depilation there was involution of cutaneous appendages. Scarring of the dermis appeared to add support to the grafts. Our findings demonstrate that the rotary door sternohyoid myocutaneous flap is a reliable, well-vascularized flap that can have extensive application in laryngotracheal reconstruction.

Animals↗
PubMed1985

Rare tumors of the skull base and temporal bone.

Skull base surgery has advanced significantly in the last decade. Neuro-otologists and neurosurgeons are working together to apply their combined expertise to totally remove skull base lesions with minimal additional neurologic deficit. Standard approaches have been developed for the more common lesions of the skull base, such as the glomus jugular tumor. Rare tumors of the skull base can be removed using the standard skull base surgery techniques. However, there are specific problems with some of these tumors. This article will describe four types of unusual skull base tumors: hyalinized chemodactoma, giant cell tumor of the bone, papillary adenoma of the middle ear, and ganglioneuroma. The unique properties of these tumors and the surgical approach to their removal will be presented and illustrated by case reports.

Adult↗
PubMed1984

Antigenic phenotype of splenic hairy cells.

Hairy cell leukemia, a distinct clinical and morphologic lymphoproliferative disorder, is characterized by the proliferation of mononuclear cells of uncertain derivation. Attempts to identify the cell of origin have used studies either of functional capabilities or of membrane/cytoplasmic antigens. Only a few cases have been studied via monoclonal antibodies. Frozen sections of splenic tissue involved with hairy cell leukemia were studied with a variety of monoclonal antibodies having specificity for differentiation antigens using the avidin-biotinylated peroxidase complex technique. Conventional direct and indirect immunohistochemical study was used for immunoglobulin heavy and light chains. In all but one case, the neoplastic cells expressed monoclonal immunoglobulin. Although T cells were identified in persisting periarteriolar sheaths and occasionally admixed with red blood cells in pseudosinuses, phenotypic expression of intrathymic or peripheral T cell antigens by the proliferating neoplastic cells was not observed. Conversely, expression of B1 and HLA-Dr antigens by splenic hairy cells was documented in all 10 cases. Hairy cell leukemia cells did not express either monocyte antigens (M1 and MO2) or the antigens expressed by early (J5) and intermediate (B2) B cells or plasmacytoid lymphocytes and plasma cells (T10). These immunohistochemical results with monoclonal antibodies provide further evidence that hairy cell leukemia is characterized by a combination of antigens peculiar to mature B lymphocytes.

Antibodies, Monoclonal↗
PubMed1984

Immunoregulatory Leu-7+ and T8+ lymphocytes in B-cell follicular lymphomas.

Lymphocyte subpopulations were profiled in lymph nodes and tonsils showing follicular hyperplasia and in follicular lymphomas with monoclonal antibodies on frozen tissue sections. Immunoregulatory lymphocyte subsets identified with T8 and Leu-7 monoclonal antibodies were quantified within the follicular centers (FC) of the nonneoplastic tissue and neoplastic follicles of the lymphomas with an optical grid defining a unit surface area (USA) of 0.04 mm2. T8+ cells were essentially confined to the interfollicular areas, with a few cells occupying the FC of the nonneoplastic specimens (mean, two and five cells/USA for tonsils and benign lymph nodes, respectively). Although lymphomas exhibited a similar pattern of distribution of T8+ cells, 17 T8+ cells/USA were observed in the follicular small cleaved cell (FSCL) group and eight T8+ cells/USA within the follicular mixed small cleaved and large cell (FML) group. Leu-7+ cells were almost entirely confined to the FC of the nonneoplastic tissues and increased (mean, 17 and 19 cells/USA for tonsils and benign lymph nodes, respectively) compared with the T8+ population. Variable distributions of Leu-7+ cells were found in the FSCL group, with a mean of 16 cells/USA. Very few Leu-7+ cells were present in the FML group. Natural killer cells and/or cytotoxic/suppressor T lymphocytes may play an immunoregulatory role in modulating the growth of follicular lymphomas.

Antibodies, Monoclonal↗
PubMed1983

Immunohistologic cellular phenotypes of lymphoproliferative disorders. Comprehensive evaluation of 564 cases including 257 non-Hodgkin's lymphomas classified by the International Working Formulation.

The plethora of classifications for non-Hodgkin's lymphomas (NHLs) and controversy regarding the merits of the individual classification schemes has led to the articulation of an International Working Formulation for NHL classification by a working group sponsored by the National Cancer Institute. This classification is based on both architectural and cytologic features and has been shown to have clinical relevance, but it is not an immunologic approach. With the use of frozen sections and both polyclonal and monoclonal antibodies, a comprehensive immunohistologic study was made of 564 biopsy specimens 1) for determination of the utility of the principle of monoclonality in differentiating benign from malignant lymphoproliferative disorders, 2) for definition of the immunohistochemical phenotypes of histologically benign and malignant cellular proliferations, and 3) for evaluation of the immunologic phenotype of 257 non-Hodgkin's lymphomas classified by the International Working Formulation. Two hundred seven "reactive benign" lymphoproliferations demonstrated polyclonal immunostaining. Monoclonal kappa light chain immunostaining was demonstrated in 3 of 4 cases classified as atypical hyperplasia, two of which had coexistent NHL or subsequently developed overt NHL. Frozen tissue sections were found to be essential for demonstration of immunoglobulin and glycoprotein membrane antigens. The results of immunohistochemical studies were readily integrated with the International Formulation. Although diffuse mixed and small lymphocytic lymphomas were immunologically heterogeneous (both T- and B-cell), follicular lymphomas were invariably of B-cell type, and immunoblastic lymphomas originating from homogeneous T- and B-cell populations were identified.

Antibodies, Monoclonal↗
PubMed1979

Expression of monocytic--histiocytic cytochemical markers in epithelial neoplasia.

The diagnosis of malignant histiocytosis is usually based upon typical light microscopic features of the neoplasm. Supplementary cytochemical and immunologic features have been suggested as typical of malignant histiocytosis. The present study was prompted by an unusual erythropagocytic hepatocellular carcinoma having immunologic and cytochemical markers suggesting mononuclear phagocytic origin. Twenty-four neoplasms of unquestionable epithelial origin were prospectively evaluated for activity of alpha-naphthyl acetate esterase, a cytochemical marker useful in distinguishing between the non-Hodgkin's lymphomas and malignant histiocytosis. The epithelial tumors represented a broad spectrum of tissue origins and consistently demonstrated alpha-naphthyl acetate esterase activity. Thus, erythrophagocytosis and alpha-naphthyl acetate esterase positivity may be misleading in the unusual instance in which the histopathologic differential diagnosis includes malignant histiocytosis and epithelial neoplasia. Ultrastructural assessment is useful in the exclusion of poorly differentiated carcinoma.

Carboxylic Ester Hydrolases↗