Differential Diagnosis of Salivary Gland Tumors: The utility of immunohistochemical markers in routine practice

OBJECTIVES : The purpose of this study is to determine whether selective immunohistochemical markers may aid in the differential diagnosis of morphologically difficult salivary gland tumors. STUDY DESIGN : The records and archival paraffin blocks of the Department of Oral Pathology and Microbiology, Tamil Nadu Government Dental College and Hospital, Chennai, South India, served as a source of material for this study. About 20 salivary gland tumors [PA (7), PLGAs (3), ACC (4), BAC (1), SDC (1), Clear cell salivary gland tumors (2) and unusual adenocarcinomas (2)] were selected from the record for the study. Formalin-fixed and paraffin embedded tissue sections of the tumors were immunohistochemically analyzed for the presence of SMA, CK, GFAP, c-kit, vimentin and S-100 protein (only in few cases). A standard streptovidin peroxidase procedure was used after antigen retrieval. To assure proper staining, salivary gland fragments, blood vessels and connective tissue fibers present in the sections adjacent to the tumor and within the tumor were used as internal positive controls. RESULTS : PAs exhibited positivity to CK in 100% of cases, vimentin in 71% of cases, SMA in 57% of cases and c-kit in 71% of cases. PLGAs were positive to CK, vimentin and c-kit in 100% of cases and to SMA in 50% of cases. ACCs showed positivity to CK in 50% of cases, vimentin in 25% of cases, SMA in 75% of cases and c-kit in 100% of cases. GFAP staining was negative in all ACCs, PLGAs and 70% of PAs. BAC exhibited reactivity to all markers except GFAP, whereas SDC was negative to all markers (CK, c-Kit, GFAP, SMA & Vimentin). CCC demonstrated positivity in 100% of cases to CK and SMA (stroma only) and in 50% of cases to vimentin, while c-kit and S-100 were negative. Unusual adenocarcinomas were positive to CK and negative to GFAP in 100% of cases, whereas 50% of cases were positive in vimentin, c-kit and SMA. Out of the two unusual adenocarcinomas S-100 was used in only one case, where it was positive. CONCLUSION : This study suggests that the use of IHC as a supplemental diagnostic tool in border line or difficult salivary gland tumors may well augment the routine microscopic differential, especially when the pattern of reaction is taken into consideration

Hemangiomatous Ameloblastoma: A Rare Variant

Ameloblastoma is a true neoplasm of enamel organ type tissue. It is the most common odontogenic neoplasm with more frequency in the mandible. A 20 years old male patient presented with a swelling in the right side of the mandible of 10 months duration. Orthopantomograph revealed multilocular radiolucency extending from the region of 46 to the condyle. Incision biopsy revealed features of plexiform ameloblastoma. Numerous vascular spaces of varying size were seen throughout the stroma. Excision biopsy also revealed similar findings. Based on these findings, a diagnosis of hemangiomatous plexiform ameloblastoma was made. Hemangiomatous ameloblastoma (HA) is still a controversial entity, with some pathologists ruling it out as a  separate lesion. This paper discusses the possibility that HA might be an aggressive variant of ameloblastoma and reviews relevant literature.&nbsp

Cervical lymph node metastasis in high-grade transformation of head and neck adenoid cystic carcinoma: a collective international review

Adenoid cystic carcinoma (AdCC) is among the most common malignant tumors of the salivary glands. It is characterized by a prolonged clinical course, with frequent local recurrences, late onset of metastases and fatal outcome. High-grade transformation (HGT) is an uncommon phenomenon among salivary carcinomas and is associated with increased tumor aggressiveness. In AdCC with high-grade transformation (AdCC-HGT), the clinical course deviates from the natural history of AdCC. It tends to be accelerated, with a high propensity for lymph node metastasis. In order to shed light on this rare event and, in particular, on treatment implications, we undertook this review: searching for all published cases of AdCC-HGT. We conclude that it is mandatory to perform elective neck dissection in patients with AdCC-HGT, due to the high risk of lymph node metastases associated with transformation

The development and validation of a scoring tool to predict the operative duration of elective laparoscopic cholecystectomy

Background: The ability to accurately predict operative duration has the potential to optimise theatre efficiency and utilisation, thus reducing costs and increasing staff and patient satisfaction. With laparoscopic cholecystectomy being one of the most commonly performed procedures worldwide, a tool to predict operative duration could be extremely beneficial to healthcare organisations. Methods: Data collected from the CholeS study on patients undergoing cholecystectomy in UK and Irish hospitals between 04/2014 and 05/2014 were used to study operative duration. A multivariable binary logistic regression model was produced in order to identify significant independent predictors of long (> 90 min) operations. The resulting model was converted to a risk score, which was subsequently validated on second cohort of patients using ROC curves. Results: After exclusions, data were available for 7227 patients in the derivation (CholeS) cohort. The median operative duration was 60 min (interquartile range 45–85), with 17.7% of operations lasting longer than 90 min. Ten factors were found to be significant independent predictors of operative durations > 90 min, including ASA, age, previous surgical admissions, BMI, gallbladder wall thickness and CBD diameter. A risk score was then produced from these factors, and applied to a cohort of 2405 patients from a tertiary centre for external validation. This returned an area under the ROC curve of 0.708 (SE = 0.013, p  90 min increasing more than eightfold from 5.1 to 41.8% in the extremes of the score. Conclusion: The scoring tool produced in this study was found to be significantly predictive of long operative durations on validation in an external cohort. As such, the tool may have the potential to enable organisations to better organise theatre lists and deliver greater efficiencies in care

Numerical modeling of the 26th December 2004 India Ocean tsunami at Andaman and Nicobar Islands

International audienceA numerical simulation of the 26th December 2004 Indian Ocean tsunami for the Andaman and Nicobar Islands case study is presented. The simulation approach is based on a fully nonlinear Boussinesq tsunami propagation model and included an accurate computational domain and a robust coseismic source. The simulation is first confronted to available tide gauge and run-up observations. The agreement between observations and the predicted wave heights allowed a reasonable validation of the simulation. As a result a full picture of the tsunami impact is provided over the entire coastal zone of Andaman and Nicobar Islands. The processes responsible for coastal vulnerability are discussed