Genetic abnormalities of somatostatin receptors in pituitary tumors

Somatostatin exerts antisecretive and antiproliferative effects on different endocrine cells by acting through a family of G protein-coupled receptors that includes five subtypes (SST1-5). Normal human pituitary and pituitary adenomas have been shown to express almost all SST subtypes, with the exception of SST4. Consistent with the observation that octreotide and other somatostatin analogs bind to SST2 and SST5 with high affinity, these genes have been screened for quantitative/qualitative abnormalities in tumors removed from patients with poor responsiveness to somatostatin analogs treatment. Data obtained in GH-secreting adenomas suggested that resistance to octreotide was frequently associated with low expression of SST2 mRNA, although other authors failed to confirm this finding. To date, the only mutational change involving SST2 and SST5 is the Arg to Trp substitution in codon 240 of the SST5 gene that was found in one acromegalic patient resistant to octreotide. Similarly, loss of heterozygosis at SST5 gene locus in pituitary adenomas has been described in individual tumors. In recent years, molecular studies investigated the possible association of gene polymorphisms and susceptibility to diseases and/or resistance to drugs. As far as polymorphic variants of SST genes are concerned, a possible role of SST5 C1004T and T-461C alleles in influencing GH and IGF-I levels in patients with acromegaly has been proposed. Nevertheless, polymorphic variants in SST2 and SST5 genes seem to have a minor, if any, role in determining the different responsiveness to somatostatin analogs in patients with acromegaly.     

Serrated adenoma developing into advanced colon cancer in 2 years

Received: November 13, 2000 / Accepted: April 13, 2001     

移植肾纤维化的声触诊定量评估

目的：探讨声触诊(virtual touch tissues quantification,VTQ)在评估移植肾纤维化程度中的应用价值。方
法：采用德国西门子公司生产的S2000彩色多普勒超声诊断仪独有的VTQ检测新技术检测54例移植肾,并与接受移
植肾穿刺活检或手术切除的病理结果对照分析。结果：VTQ值与移植肾纤维化不同病理分期之间呈正相关(Spearman
r=0.796,P<0.05)。结论：VTQ值可作为观测移植肾纤维化程度的无创定量观察新指标,能较好地评估移植肾的慢性
损伤。     

Bilateral,multicenteric metanephric adenoma associated with Wilms' tumor in a child: A rare presentation with important diagnostic and therapeutic implications

Metanephric adenoma is an uncommon benign renal tumor that occurs predominantly in adult females and rarely in children. On histomorphology it shows a resemblance to Wilms' tumor, nephrogenic rests and papillary renal cell carcinoma. Multifocality along with multicentricity has not been documented in English literature till date. From a diagnostic and therapeutic viewpoint, recognition of this entity is of the utmost importance, because it shows a favorable clinical outcome. We describe a rare case of bilateral, multicentric metanephric adenoma associated with triphasic Wilms' tumor (stage II) of the left kidney in a male child.     

Sinonasal Tract Adenoid Cystic Carcinoma Ex-Pleomorphic Adenoma: A Clinicopathologic and Immunophenotypic Study of 9 Cases Combined with a Comprehensive Review of the Literature

Primary sinonasal tract carcinoma ex-pleomorphic adenoma (CEPA) is very uncommon, with adenoid cystic carcinoma (ACC) CEPA exceptional. These tumors are often misclassified. This is a retrospective study. Nine cases of ACC CEPA included 7 females and 2 males, aged 39–64 years (mean, 51.1 years). Patients presented most frequently with obstructive symptoms (n = 5), epistaxis (n = 3), nerve changes or pain (n = 3), present for a mean of 25 months (men: 9.5 versus women: 29.4 months; p = 0.264). The tumors involved the nasal cavity alone (n = 5), nasopharynx (n = 2), or a combination of locations (n = 2) with a mean size of 2.9 cm (females: 3.3; males: 1.7; p = 0.064). Most patients presented at a low clinical stage (n = 7, stage I), with one patient each in stage II and IV, respectively. Histologically, the tumors showed foci of PA associated with areas of ACC. Tumors showed invasion (lymph-vascular: n = 4; perineural: n = 6; bone: n = 6). The neoplastic cells were arranged in tubules, cribriform and solid patterns, with peg-shaped cells arranged around reduplicated basement membrane and glycosaminoglycan material. Mitoses ranged from 0 to 33, with a mean of 8.7 mitoses/10 HPFs. Necrosis (n = 2) and atypical mitotic figures (n = 1) were seen infrequently. Immunohistochemical studies showed positive reactions for cytokeratin, CK5/6, p63, CK7, EMA, SMA, calponin, S100 protein and CD117, several highlighting luminal versus basal cells components. GFAP, CK20 and MSA were non-reactive. p53 and Ki-67 were reactive to a variable degree. Surgery (n = 8), accompanied by radiation therapy (n = 5) was generally employed. Five patients developed a recurrence, all of whom died with disease (mean, 8.4 years), while 4 patients are either alive (n = 2) or had died (n = 2) without evidence of disease (mean, 15.9 years). In summary, ACC CEPA probably arises from the minor mucoserous glands of the upper aerodigestive tract, usually presenting in patients in middle age with obstructive symptoms in a nasal cavity based tumor. Most patients present with low stage disease (stage I and II), although invasive growth is common. Recurrences develop in about a 55 % of patients, who experience a shorter survival (mean, 8.4 years) than patients without recurrences (mean, 15.9 years). The following parameters, when present, suggest an increased incidence of recurrence or dying with disease: bone invasion, lymph-vascular invasion, and perineural invasion.     

p16 Immunohistochemistry As a Standalone Test for Risk Stratification in Oropharyngeal Squamous Cell Carcinoma

Ectopic sphenoid sinus pituitary adenoma (ESSPA) may arise from a remnant of Rathke’s pouch. These tumors are frequently misdiagnosed as other neuroendocrine or epithelial neoplasms which may develop in this site (olfactory neuroblastoma, neuroendocrine carcinoma, sinonasal undifferentiated carcinoma, paraganglioma, melanoma). Thirty-two patients with ESSPA identified in patients with normal pituitary glands (intact sella turcica) were retrospectively retrieved from the consultation files of the authors’ institutions. Clinical records were reviewed with follow-up obtained. An immunohistochemical panel was performed on available material. Sixteen males and 16 females, aged 2–84 years (mean, 57.1 years), presented with chronic sinusitis, headache, obstructive symptoms, and visual field defects, although several were asymptomatic (n = 6). By definition, the tumors were centered within the sphenoid sinus and demonstrated, by imaging studies or intraoperative examination, a normal sella turcica without a concurrent pituitary adenoma. A subset of tumors showed extension into the nasal cavity (n = 5) or nasopharynx (n = 9). Mean tumor size was 3.4 cm. The majority of tumors were beneath an intact respiratory epithelium (n = 22), arranged in many different patterns (solid, packets, organoid, pseudorosette-rosette, pseudopapillary, single file, glandular, trabecular, insular). Bone involvement was frequently seen (n = 21). Secretions were present (n = 16). Necrosis was noted in 8 tumors. The tumors showed a variable cellularity, with polygonal, plasmacytoid, granular, and oncocytic tumor cells. Severe pleomorphism was uncommon (n = 5). A delicate, salt-and-pepper chromatin distribution was seen. In addition, there were intranuclear cytoplasmic inclusions (n = 25) and multinucleated tumor cells (n = 18). Mitotic figures were infrequent, with a mean of 1 per 10 HPFs and a <1% proliferation index (Ki-67). There was a vascularized to sclerotic or calcified stroma. Immunohistochemistry highlighted the endocrine nature of the tumors, with synaptophysin (97%), CD56 (91%), NSE (76%) and chromogranin (71%); while pan-cytokeratin was positive in 79%, frequently with a dot-like Golgi accentuation (50%). Reactivity with pituitary hormones included 48% reactive for 2 or more hormones (plurihormonal), and 33% reactive for a single hormone, with prolactin seen most frequently (59%); 19% of cases were non-reactive. The principle differential diagnosis includes olfactory neuroblastoma, neuroendocrine carcinoma, melanoma, and meningioma. All patients were treated with surgery. No patients died from disease, although one patient died with persistent disease (0.8 months). Surgery is curative in the majority of cases, although recurrence/persistence was seen in 4 patients (13.8%). In conclusion, ESSPAs are rare, affecting middle aged patients with non-specific symptoms, showing characteristic light microscopy and immunohistochemical features of their intrasellar counterparts. When encountering a tumor within the sphenoid sinus, ectopic pituitary adenoma must be considered, and pertinent imaging, clinical, and immunohistochemical evaluation undertaken to exclude tumors within the differential diagnosis. This will result in accurate classification, helping to prevent the potentially untoward side effects or complications of incorrect therapy.     

3D-Slicer软件在神经内镜经鼻蝶入路垂体腺瘤手术中的应用

目的 探讨3D-Slicer软件辅助神经内镜经鼻蝶入路垂体腺瘤手术的疗效与价值。方法 28例垂体腺瘤患者行头颅CT和头颅MRI检查,将影像数据输入3D-Slicer软件,对蝶窦、鞍区骨性结构、垂体腺瘤及颈内动脉、视神经结构进行三维重建,并行术前规划,判断神经血管和肿瘤的空间关系,模拟磨除鞍底的过程,将重建图像与术中图像进行比较,评价两者吻合程度,记录术后并发症和疗效。结果 所有患者的三维重建图像中,蝶窦、鞍区骨性结构、垂体腺瘤及神经血管均可清晰显示,与术中内镜下实际图像高度匹配,能准确识别重要结构,并规划出鞍底骨窗的合适范围。所有患者手术过程顺利,术后均未发生严重并发症。结论 3D-Slicer软件运用于神经内镜下经鼻蝶入路垂体腺瘤手术,有助于术前明确显示蝶窦、蝶鞍、肿瘤与神经血管的空间关系,可帮助提高手术安全性与手术效率。     

Distal renal tubular acidosis associated with Sjogren syndrome

Renal tubular acidosis is a common cause of normal anion gap metabolic acidosis but these disorders can be easily missed or misdiagnosed. We highlight the approach to assessing renal tubular acidosis by discussing a case study with a temporal data set collected over more than 5 weeks. We highlight the principles and the necessary information required for a diagnosis of classic distal renal tubular acidosis. We also briefly review several aspects of type 1 renal tubular acidosis related to autoimmune disease, drugs and thyroid disorders.