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Stefan Pambuccian

Publications and source records attributed to Stefan Pambuccian.

9 recordsLinked to original sources
PubMed2006

Differential gene expression identifies subgroups of renal cell carcinoma.

Clear cell carcinoma of the kidney, the most common subtype of renal cell cancer, displays different biological behavior in different patients. This heterogeneity cannot be recognized by light microscopy. In this study, gene expression in 16 clear cell renal cell carcinoma samples and 17 non-malignant tissue types comprising 539 samples was determined using oligonucleotide microarrays representing approximately 40,000 known genes and ESTs. Differences in gene expression were quantified as the fold change in gene expression between the various sets of samples. A set of genes was identified that was overexpressed in the renal cell carcinoma samples compared with the normal kidney samples. Principle component analysis of the set of renal cell carcinomas using this set of genes overexpressed in renal cell cancer revealed the existence of 2 major subgroups among the renal carcinomas. A series of principle component analyses of the set of renal cell carcinomas using different gene sets composed of genes involved in different metabolic pathways also revealed the same 2 major subgroups of the renal cell cancers. Eisen clustering using the same genes also revealed the same 2 major renal cell cancer subsets. Review of the pathology suggested that these 2 subgroups differed in pathologic grade. Genes differentially expressed between the 2 renal cell cancer subsets were identified. Examination of gene expression in each renal cell cancer subset and the pool of renal cell carcinoma samples compared with that in 17 different normal tissues revealed genes specifically overexpressed in renal cell cancer compared with these normal tissues. The authors conclude that gene expression patterns may be useful in helping to further classify subtypes of renal cell carcinoma that may have clinical significance. In addition, the genes identified as overexpressed in each set of clear cell renal cell carcinomas compared with normal tissues may represent useful targets for therapy.

Adult↗
PubMed2003

Germ cell tumor-like neoplasms occurring outside the anatomic midline.

Most germ cell tumors occur in the gonads or in extragonadal sites in the anatomic midline; this article reviews tumors with similar or identical histologic features that arise in other topographic locations. Such lesions often represent the presence of "germ cell-like" or "germinal" components in what is otherwise recognized as a somatic neoplasm; however, they may also occur in pure form. The morphologic and immunohistochemical features of these proliferations are reviewed, according to the types of germ cell tumors that they recapitulate.

Biomarkers, Tumor↗
PubMed2003

Subglottic laryngeal paraganglioma.

OBJECTIVES: To review the clinical and pathological picture of laryngeal paragangliomas and compare laryngeal paragangliomas with the three other types of laryngeal neuroendocrine neoplasms. STUDY DESIGN: The study presents a case review of a patient with a subglottic laryngeal paraganglioma treated at our institution, with a literature review of the laryngeal neuroendocrine neoplasms. Included is a review of all four neuroendocrine neoplasms, taking a close look at a comparison between laryngeal paragangliomas and atypical carcinoids tumors. All cases of subglottic laryngeal paragangliomas reported in the literature were also compiled and tabulated. METHODS: The patient's record was reviewed for age, symptomatology, workup, and surgical procedures performed. RESULTS: The patient was disease free 36 months after undergoing a tracheostomy for airway control, followed by a cricoid split for complete excision of the tumor. CONCLUSIONS: It is important to differentiate among the four laryngeal neuroendocrine neoplasms, especially between atypical carcinoids and paragangliomas. Each tumor requires different treatments, with the former requiring a more aggressive approach. Paragangliomas must be completely excised to prevent their recurrence, and this approach should be considered a curative treatment. In addition, the immunohistochemical battery is of paramount importance in obtaining the correct pathological diagnosis.

Aged↗
PubMed2002

Clinical case seminar: hypoglycemia after pancreas transplantation: association with allograft nesidiodysplasia and expression of islet neogenesis-associated peptide.

We report a case of severe hypoglycemia occurring in a 35-yr-old woman, 6 yr after pancreas transplantation for type 1 diabetes mellitus. Extensive preoperative and intraoperative exploration failed to disclose the presence of a focal adenomatous lesion. Partial allograft pancreatectomy was performed initially, but it failed to control the hypoglycemic symptoms, leading to complete removal of the pancreas allograft. Histopathological examination of the resected pancreas allograft showed the presence of nesidioblastosis, characterized by foci of islet cells budding off ducts, accompanied by an increase in the number of islets, numerous small intralobular islet cell aggregates, and nesidiodysplasia (large, hyperchromatic islet cell nuclei). Islet neogenesis-associated protein-positive islets and ducts were seen by immunofluorescence. Insulin-positive islets ranged from very small to large, with isolated insulin-positive cells diffusely scattered, consistent with islet neogenesis. Very little glucagon staining was identified. Reported cases of adult nesidioblastosis are reviewed. The significance of nesidioblastosis in the context of pancreas transplantation and possible mechanisms of posttransplant hypoglycemia are discussed.

Adult↗
PubMedDate not supplied

Nasopharyngeal amyloidosis.

PURPOSE: To discuss the presentation of localized amyloidosis affecting the nasopharynx and discuss the management options. Amyloidosis in the head and neck is a rare and benign condition that usually takes the form of localized amyloidosis. Because systemic amyloidosis markedly shortens life expectancy owing to its involvement with vital organs, rectal biopsy or fat aspiration of the anterior abdominal wall must be carried out to exclude systemic involvement. Localized amyloidosis in the head and neck can involve the orbit, sinuses, nasopharynx, oral cavity, salivary glands, and larynx. METHODS: We present the case of a patient with conductive hearing loss and serous otitis media with effusion secondary to nasopharyngeal amyloidosis, as well as present a review of the literature. RESULTS: Only a few cases of nasopharyngeal amyloidosis have thus far been reported. Patients with this disease can also present with recurrent epistaxis, postnasal drip, nasal obstruction, and eustachian tube dysfunction. Localized amyloidosis of the nasopharynx, which is slow growing, has proved difficult to treat because it can persist or recur despite surgical treatment. Furthermore, bleeding may be a major complication in treating patients with nasopharyngeal amyloidosis by transpalatal excision because the amyloid deposits cause vascular wall fragility. Finally, there is no evidence that surgical treatment of nasopharyngeal amyloidosis can prolong survival or that localized amyloidosis can progress to systemic amyloidosis. For these reasons, we elected to treat our patient with a tympanostomy tube and observation. CONCLUSION: In the absence of systemic disease, localized amyloidosis of the nasopharynx may be treated conservatively.

Aged↗
PubMedDate not supplied

Orbital chondroma.

A 9-year-old boy was referred for increasing ptosis in the left eye. CT and MRI revealed a well-circumscribed mass in the superonasal orbit. An anterior orbitotomy was performed and the mass was excised in toto. Pathologic evaluation revealed a pure chondroma. Chondroma is an uncommon tumor that may rarely present as an orbital mass.

Child↗
PubMedDate not supplied

Hepatic encephalopathy secondary to transtumoral portal-hepatic venous shunting.

Intrahepatic portal-systemic shunts causing hepatic encephalopathy are very rare. This is a case report of a patient with hepatic metastases of a pancreatic islet cell tumor that manifested with transtumoral shunts leading to hepatic encephalopathy. The diagnosis was confirmed with Doppler ultrasound and initially treated with selective transhepatic portal vein embolization followed by hepatic artery embolization, and eventually radiofrequency ablation of the largest metastases. Despite excellent short-term palliation, symptom recurrence necessitated liver resection, the results of which proved durable. A multidisciplinary treatment plan for the identification and management of potentially salvageable encephalopathy in similar patients is described.

Carcinoma, Islet Cell↗