A 51-year old woman underwent mastoidectomy with labyrinthectomy on the right for a polypoid external auditory canal mass accompanied by tinnitus and ear discharge. She was reported to have undergone mastoidectomy on the same site seven years prior to the present consult. The material from this prior surgery was not made available to us.

The submitted specimen from this surgery consisted of several dark brown irregular tissue fragments with an aggregate diameter of 4.2 centimeters. Histologic sections show tumor cells arranged in "ball-like" clusters, that are surrounded by a network of sinusoidal channels. The cells are round to oval, with round, uniform nuclei that have finely granular chromatin, and moderate amounts of eosinophilic to amphophilic cytoplasm. (Figure 1)  Mitoses, nuclear pleomorphism and hyperchromasia are not observed. Immunohistochemical studies show diffuse cytoplasmic positivity for synaptophysin and chromogranin. (Figure 2)  The S100 stain highlights a peripheral layer of cells taking up the stain around the cell clusters. (Figure 3)  Based on these features, we diagnosed the case as a paraganglioma, likely a recurrence.

Paragangliomas are neuroendocrine neoplasms that arise from paraganglia found in various anatomic locations.1 In the middle ear, they arise from paraganglia found in the adventitia of the jugular bulb - hence, the old synonym "glomus jugulare" and "glomus tympanicum." Other sites where they can develop include paraganglia of the carotid artery bifurcation ("chemodectoma"), the larynx, and the vagal trunk ("glomus vagale"). The World Health Organization has simplified the nomenclature of these tumors by calling all of them simply "paraganglioma" and specifying the site involved.1 In our case, it is likely a middle ear paraganglioma, borne out by the history, clinical picture, and the morphology. Head and neck paragangliomas occur in adults, from the 5th - 6th decade, more commonly in females, and present mostly with mass-related symptoms.2,3

The morphology of paragangliomas in all head and neck locations is similar. Hematoxylin-eosin sections show cells arranged in organoid groups ("cell-ball", "Zellballen") surrounded by a vascular network. There are two cell types encountered: the chief cells, which comprise the bulk of the cell nests and have abundant eosinophilic cytoplasm, and the sustentacular cells, which are spindly and located at the periphery of the nests. Neuroendocrine immunohistochemical stains (e.g. synaptophysin, chromogranin, CD56) highlight the chief cells, while S100 and glial fibrillary acidic protein (GFAP) highlight the sustentacular cells. Cytokeratin is typically non-reactive and distinguishes this tumor from neuroendocrine tumors (i.e. carcinoid, neuroendocrine carcinoma), and middle ear adenoma.1,3 There are no consistent histologic features that can discriminate between benign and malignant cases, nor are there criteria that can predict aggressive behavior and metastasis.1,2,3

Head and neck paragangliomas are slow-growing tumors, and surgery is the most common treatment option. Radiotherapy is an option, especially for vagal paragangliomas where severe vagal nerve deficits occur in surgically treated cases.1 Recurrence after surgery is reported to be less than 10% for carotid, and up to 17% in laryngeal cases.1 Metastasis on the other hand occur in 4 - 6 % of carotid, 2% of middle ear and laryngeal, and 16% of vagal tumors.3 The World Health Organization nomenclature states that "all paragangliomas have some potential for metastasis (albeit variable)."1 Thus, long-term follow-up may be prudent for all cases.

BACKGROUND: Making the distinction between large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC) is difficult in some samples of biopsy tissues, but we have to separate LCNEC from SCLC because the two types of cancer may need different therapy and they have different prognostic implications. Thus far, there are no specific immunohistochemical markers that allow distinguishing these two kinds of tumors. METHODS: We performed an immunohistochemical analysis to study the expressions of p63, Bcl-2, and 34betaE12 and to investigate whether these 3 molecules have correlations in LCNEC and SCLC. We also evaluated the expression of the neuroendocrine markers chromogranin, synaptophysin and CD56. RESULTS: A statistical analysis was performed for p63, Bcl-2, and 34betaE12 in separate and combined panels. According to the combinations of p63, Bcl-2, and 34betaE12, there were frequent expressions of p63-/Bcl-2+ or Bcl-2+/34betaE12- in the SCLC, and there was a superior proportion of them in the SCLC rather than that in the LCNEC. The p63-/Bcl-2+ and Bcl-2+/34betaE12- antibody combinations showed higher specificities compared to any single antibody for diagnosing SCLC. CONCLUSIONS: Bcl-2 and selective p63 or 34betaE12 made up a most useful panel of markers for making the differential diagnosis of LCNEC and SCLC.
Biopsy ; Carcinoma, Neuroendocrine ; Diagnosis, Differential ; Small Cell Lung Carcinoma ; Synaptophysin

Neuroendocrine tumor (NET) of the major duodenal papilla is a rare occurrence. However, that of the minor duodenal papilla is even rarer. To date, only a few cases have been reported. Herein, we present a rare case of NETs detected at the major and minor duodenal papilla synchronously, which were successfully treated with endoscopic papillectomy without procedure-related complication. To the best of our knowledge, this is the first report of this kind in the world. Photomicrograph of the biopsy specimen stained immunohistochemically for synaptophysin showed a positive reaction of tumor cells. All resection margins were negative. Further experience with more cases will be needed to establish the exact indication of endoscopic papillectomy for duodenal papillary NETs.
Ampulla of Vater ; Biopsy ; Neuroendocrine Tumors* ; Pancreatic Ducts* ; Synaptophysin

Primary dissociated neuronal cultures are widely used research tools to investigate of pathological mechanisms and to treat various central and peripheral nervous system problems including trauma and degenerative neuronal diseases. We introduced a protocol that utilizes hippocampal and cortical neurons from embryonic day 17 or 18 mice. We applied appropriate markers (GAP-43 and synaptophysin) to investigate whether neurite outgrowth and synaptogenesis can be distinguished at a particular period of time. GAP-43 was found along the neural processes in a typical granular pattern, and its expression increased proportionally as neurites lengthened during the early in vitro period. Unlike GAP-43, granular immunoreactive patterns of synaptophysin along the neurites were clearly found from day 2 in vitro with relatively high immunoreactive levels. Expression of synaptic markers from cortical neurons reached peak level earlier than that of hippocampal neurons, although neurite outgrowths of hippocampal neurons were faster than those of cortical neurons. The amount of peak synaptic markers expressed was also higher in cortical neurons than that in hippocampal neurons. These results strongly suggest the usefulness of primary cultured neurons from mice embryos for synaptic function and plasticity studies, because of their clear and typical patterns of morphology that establish synapses. Results from this study also suggest the proper amount of time in vitro according to neuronal types (cortical or hippocampal) when utilized in experiments related with synaptogenesis or synaptic activities.
Animals ; Embryonic Structures ; GAP-43 Protein ; Mice ; Neurites ; Neurons ; Peripheral Nervous System ; Plastics ; Synapses ; Synaptophysin

The authors report a case of atypical extraventricular neurocytoma (EVN) transformed from EVN which had been initially diagnosed as an oligodendroglioma 15 years ago. An 8-year-old boy underwent a surgical resection for a right frontal mass which was initially diagnosed as oligodendroglioma. When the tumor recurred 15 years later, a secondary operation was performed, followed by salvage gamma knife treatment. The recurrent tumor was diagnosed as an atypical EVN. The initial specimen was reviewed and immunohistochemistry revealed a strong positivity for synaptophysin. The diagnosis of the initial tumor was revised as an EVN. The patient maintained a stable disease state for 15 years after the first operation, and was followed up for one year without any complications or disease progression after the second operation. We diagnosed an atypical extraventricular neurocytoma transformed from EVN which had been initially diagnosed as an oligodendroglioma 15 years earlier. We emphasize that EVN should be included in the differential diagnosis of oligodendroglioma.
Child ; Diagnosis, Differential ; Disease Progression ; Humans ; Immunohistochemistry ; Neurocytoma ; Oligodendroglioma ; Recurrence ; Synaptophysin

Carcinoid tumors arising in the extrahepatic bile duct are very rare, accounting for only 0.2%~2% of all gastrointestinal carcinoid tumord. We experienced one case of a carcinoid tumor in the common bile duct. A 43-years-old man was unexpectedly found to have a carcinoid tumor of the common bile duct. This patient had no obstructive jaundice, yet we thought that this tumor was a clinically malignant tumor, so we performed pylorus preserving pancreatoduodenectomy. Pathologically, an ill-demarcated mass that measured 1.5x1.5cm in size had invaded into the pancreas. Immunohistochemically, the mass was founded to be chromogranin, synaptophysin and CD56 positive. The patient who underwent curative resection is alive and disease-free at time of this publication. This report also reviews the relevant literature on carcinoid tumors in the common bile duct.
Bile Ducts, Extrahepatic ; Carcinoid Tumor* ; Common Bile Duct* ; Humans ; Jaundice, Obstructive ; Pancreas ; Pancreaticoduodenectomy ; Publications ; Pylorus ; Synaptophysin

PURPOSE: The aim of this study was to review our experience with neuroendocrine carcinoma (NEC) of the colon and rectum to highlight the clinical and pathological characteristics in this relatively uncommon malignancy. METHODS: From December 1995 to December 2006, 11 patients with NEC were identified from our database of 6,143 colorectal cancer patients (0.18%), which does not include carcinoid tumors. The pathology was retrospectively reviewed and the tumors were categorized as pure NEC, including well-differentiated NEC (n=3), poorly-differentiated (n=3) and mixed endocrine/exocrine tumor (n=5) on the basis of the histology and immunohistochemical findings. RESULTS: The mean age of the patients was 57 yr (range, 37 to 69 yr). The tumors were located as follows: 8 in the colon and 3 in the rectum. The diagnosis of NEC was suggested preoperatively from the tissue biopsy in 2 of 9 patients (22.2%). The tumors were advanced at the time of diagnosis, with American Joint Committee on Cancer Stage III (n=7) and Stage IV disease (n=4). Most tumors stained positive by immunohistochemistry for neuroendocrine markers, including synaptophysin (7/9, 77.8%); however, chromogranin was expressed in 4 of 9 NEC tumors (44.4%). Metastatic disease was detected at the time of diagnosis in 36.4% (4/11) of the patients. The median survival for NEC was 16 mo (3.6-67.4 mo), and for pure NEC and mixed endocrine/exocrine tumor was 4.1 mo and 23.6 mo, respectively. CONCLUSION: NEC had distinctive cytoarchitectural features and was often immunoreactive for neuroendocrine markers. Our findings showed that pure NEC had aggressive behavior and a poor prognosis.
Biopsy ; Carcinoid Tumor ; Carcinoma, Neuroendocrine ; Colon ; Colorectal Neoplasms ; Humans ; Immunohistochemistry ; Joints ; Prognosis ; Rectum ; Retrospective Studies ; Synaptophysin

Central neurocytoma is a rare, well-differentiated neuronal tumor and is usually located in the lateral or third ventricle of young adults. The occurrence of an intraventricular tumor with a characterisitic magnetic resonance image findings including isointense signal in T1-weighted images, the presence of a cystic component, small signal-void areas due to calcification, heterogenous and hyperintense "bubbly" appearance in T2-weighted images in a young patient should suggest preoperatively the diagnosis of central neurocytoma. The typical immunohistochemical finding, positivity for synaptophysin, is the main pathological feature. We experienced two cases of central neurocytomas with typical radiological and histopathological findings. We expect growth arrest of these cases by subtotal removal to avoid postoperative neurologic deficit followed by radiation therapy.
Diagnosis ; Humans ; Neurocytoma* ; Neurologic Manifestations ; Neurons ; Synaptophysin ; Third Ventricle ; Young Adult

Primary carcinoid tumor of the kidney is a very rare disease. Until now, only 41 cases have been reported worldwide, and nine of these arose in a horseshoe kidney. In Korea, 3 cases have been reported to date, and all of these arose in a horseshoe kidney. We present a case of primary carcinoid tumor occurring in a normal kidney of a 45 year old man. A tumor was incidentally found close to the hilum of the left kidney. Histologically, the tumor exhibited trabecular and ribbon-like pattern of cuboidal or columnar cells. Mitotic activity was rarely seen. The tumor cells were positive for synaptophysin and chromogranin A. Numerous dense-core neurosecretary granules were observed by the electron microscopic examination. To our knowledge, the present case is the first report of primary renal carcinoid tumor arising in a normal kidney in Korea.
Carcinoid Tumor* ; Chromogranin A ; Humans ; Kidney* ; Korea ; Middle Aged ; Rare Diseases ; Synaptophysin

We report a case of extraventricular neurocytoma(left parietal lobe) in a young man presented with hemiparesis. The tumor, a radiologically well-circumscribed, cystic and enhancing mass, was partially removed. The patient, who received postoperative radiotherapy, is living well after 15 months of follow-up. Pathology showed a well-differentiated lesion composed of uniform, round cells with perinuclear halos in a neuropil background, immunohistochemically positive for neuronal markers. This was a cystic extraventricular neurocytoma(glio-neuronal tumor) arising from the left parietal lobe. Its features were consistent with neurocytoma pathologically and were different from those of intraventricular neurocytoma pathophysiologically. We outline the morphological and immunohistochemical evaluations necessary to recognize this rare tumor.
Follow-Up Studies ; Humans ; Neurocytoma* ; Neurons ; Neuropil ; Paresis ; Parietal Lobe ; Pathology ; Rabeprazole ; Radiotherapy ; Synaptophysin