Oncocytic low-grade myoepithelial carcinoma ex pleomorphic adenoma - A rare case illustrating key learning points.

BACKGROUND: Oncocytic myoepithelial carcinoma ex pleomorphic adenoma neoplastic is a rare neoplastic event and may not display overt malignant radiological features. METHODS: Using routine histopathology and immunohistochemistry, we characterize a case of low-grade oncocytic carcinoma ex pleomorphic adenoma. RESULTS: The tumor arose in the left parotid gland in a 59 year old female. Computed tomography (CT) imaging demonstrated a well-defined, lobulated, enhancing lesion with relative central stellate hypoenhancement. Histologically, the tumor displayed a multi-nodular, non-destructive, invasive pattern, low mitotic activity (one mitotic figure per 10 high power fields) and a small remnant focus of pleomorphic adenoma. The neoplastic cells showed significant expression of cytokeratin 5/6, S-100 protein, smooth muscle actin and p63. CONCLUSION: Low-grade oncocytic carcinoma ex pleomorphic adenoma is a challenging histopathological diagnosis which can be established with use of immunohistochemistry, generous tumor sampling and recognition of the multi-nodular, non-destructive, pattern of invasion. In the absence of clear-cut tumor encroachment into external structures, its malignant nature may not be easily identified on pre-operative imaging.

Mortality and Neurological Outcomes in Out-of-Hospital Cardiac Arrest Patients With and Without Targeted Temperature Management in a Multiethnic Asian Population.

INTRODUCTION: The use of targeted temperature management (TTM) is increasing although adoption is still variable. We describe our 6-year experience and compare the mortality and neurological outcomes of out-of-hospital cardiac arrest (OHCA) patients with and without the use of TTM in a multiethnic Asian population. MATERIALS AND METHODS: We performed a retrospective observational study at a tertiary academic medical centre. OHCA survivors admitted to our hospital between April 2010‒December 2016 were included. Outcomes of interest were 30-day mortality postresuscitation, Cerebral Performance Category (CPC) and Overall Performance Category (OPC) scores. RESULTS: A total of 121 of 261 patients (46.3%) underwent TTM. TTM patients were younger (TTM 60.0 years old vs no TTM 63.7 years old, P = 0.047). There was no difference in the initial arrest rhythm of shockable origin between the 2 groups (P = 0.289). There was suggestion of lower 30-day mortality (TTM 24.3% vs no TTM 31.4%, P = 0.214), higher and good CPC/OPC scores (TTM 19.0% vs no TTM 15.7%, P = 0.514) with TTM although this did not reach statistical significance. On multivariable logistic regression analysis, TTM was not associated with 30-day mortality (P = 0.07). However, older age, initial non-shockable rhythm and increased duration from arrest to return of spontaneous circulation were associated with increased mortality. Malay ethnicity was associated with a poorer CPC/ OPC score. CONCLUSION: Adoption and outcomes of TTM postresuscitation is variable and there is still a need to optimise management of the identified predictors of survival and good neurological outcomes while TTM is being used.