The role of urinary fractionated metanephrines in the diagnosis of phaeochromocytoma.

Background & objectives: Plasma and urinary metanephrines are used as screening tests for the diagnosis of phaeochromocytoma. The recommended cut-off levels are not standardized. This study was conducted to identify a cut-off level for 24 h urinary fractionated metanephrines viz. metanephrine (uMN) and normetanephrine (uNMN) using enzyme immunoassay for the diagnosis of phaeochromocytoma. Methods: Consecutive patients suspected to have phaeochromocytoma were included in the study. uMN and uNMN in 24 h urinary sample were measured using a commercial ELISA kit. Results: Overall, 72 patients were included over a period of 18 months. Twenty patients had histopathologically confirmed phaeochromocytoma and in 52 patients phaeochromocytoma was ruled out. Using the upper limit of normal stated by the assay manufacturer as the cut-off, uMN >350 μg/day had a low sensitivity and uNMN >600 μg/day had a poor specificity. By increasing the cut-off value of uNMN to twice the upper limit, specificity increased significantly without much loss in sensitivity. Combining uMN and uNMN using a cut-off twice the upper limit improved the diagnostic performance - sensitivity (95%); specificity (92.3%); positive predictive value (PPV - 82.6%); negative predictive value (NPV - 98%). In subsets of patients with a variable pretest probability for phaeochromocytoma, the PPV correlates well with the occurred of these tumors decreased, while the NPV remained at 100 per cent. Interpretation & conclusions: ELISA is a simple and reliable method for measuring uMN and uNMN. The test has a good NPV and can be used as an initial screening test for ruling out phaeochromocytoma. Each hospital will have to define the cut-off value for the assay being used, choosing a proper control population.

Discriminating thyroid cancers from benign lesions based on differential expression of a limited set of miRNA using paraffin embedded tissues.

Background : Micro-RNAs (miRNAs) are expressed in a tissue-specific manner and are known to demonstrate differential expression even among the various subtypes of a given tumor. This differential expression has been harnessed successfully in the development of diagnostic assays for various malignant tumors. These assays have been found to be relevant and of value as additional diagnostic tools even among thyroid tumors, particularly with regard to thyroid carcinomas of follicular morphology. Materials and Methods : A limited set of miRNA have been assessed as part of this study in an effort to use minimal number of miRNA markers (miR-187, miR-221, miR-222, and miR-224) to differentiate the benign from the malignant thyroid tumors using miRNA derived from paraffin embedded material. Results : While miR-221 and miR-222 were found to provide good accuracy as individual markers (86% and 84%), a combination of the two provided slightly better accuracy (91%). Both miR-221 and 222 were able to significantly differentiate malignant tumors from the benign samples (P< 0.001) individually and as a combination of markers. However, inclusion of miR-187 and miR-224 in the panel did not provide any additional benefit. Conclusion : While a combination of miR-221 and 222 when used in a diagnostic panel could provide fairly good accuracy additional markers may need to be investigated to augment their diagnostic utility.

The abdominal cocoon and an effective technique of surgical management.

The Abdominal Cocoon is a very rare cause of small bowel obstruction. It is caused by encapsulation of the small bowel by a fibrous membrane. This tropical disease, seen in young females, has also been reported in males. This is one of the largest series of the Abdominal Cocoon, with five new patients (3 males and 2 females) being reported. The traditional surgical treatment of choice is by lysis of adhesions. All patients in this case series had small bowel intubation done in addition to adhesiolysis. Although small bowel intubation is an established procedure for various causes of recurrent small bowel obstruction, to our knowledge this is the first report of its use in the management of the Abdominal Cocoon. We report our surgical technique in the management of this rare disease.