Patterns of SATB2 and p16 reactivity aid in the distinction of atypical polypoid adenomyoma from myoinvasive endometrioid carcinoma and benign adenomyomatous polyp on endometrial sampling.

AIMS: Atypical polypoid adenomyoma (APAM) is an uncommon uterine lesion composed of complex endometrioid glands with frequent squamous morular metaplasia and fibromuscular stroma. On endometrial curettage, biopsy or polypectomy specimens, the admixture of endometrioid glands and smooth muscle raises the differential diagnosis of myoinvasive endometrioid carcinoma. Reproductive-age APAM patients may opt for fertility preservation, whereas myoinvasive carcinoma is treated surgically. One previous study reported an incidental finding that the stroma of APAM, in contrast to that of other polypoid lesions, was SATB2-positive. APAM has also been reported to show increased stromal p16 staining. We aimed to assess whether SATB2 and p16 are useful stains for the distinction of APAM from myoinvasive carcinoma and benign adenomyomatous polyps. METHODS AND RESULTS: Cases of 'atypical polypoid adenomyoma' (n = 32), 'adenomyomatous polyp' (n = 39) and 'myoinvasive endometrioid carcinoma' (n = 30) were identified. Morphological features were assessed, along with the intensity and extent of SATB2 and p16 staining in the stromal component of each lesion. SATB2 expression was seen in the stromal components of 30 of 32 (94%) APAMs, versus none of 39 (0%) benign adenomyomatous polyps and five of 30 (17%) myoinvasive endometrioid carcinomas. Stromal p16 expression was seen in 31 of 31 (100%) APAMs, versus 20 of 39 (51%) benign adenomyomatous polyps and 12 of 30 (40%) myoinvasive endometrioid carcinomas. CONCLUSIONS: Patchy to diffuse SATB2 and block-type p16 staining of fibromuscular stroma separating atypical endometrioid glands is more consistent with APAM than with myoinvasive endometrioid carcinoma. These stains are potentially useful adjuncts to careful morphological evaluation of endometrial biopsies/curettings.

Update in neonatal diabetes.

PURPOSE OF REVIEW: Here we give context to new data on neonatal diabetes mellitus, a rare group of insulin-requiring monogenic forms of diabetes presenting at birth or shortly thereafter. Genetic studies are critical in the diagnosis and treatment of these patients. The most common causes of neonatal diabetes are activating mutations in the two protein subunits of the ATP-sensitive potassium channel. These are responsible for about half of all cases of permanent neonatal diabetes and some cases of transient neonatal diabetes. Identification of these mutations allows patients treated with insulin to be transferred to sulfonylureas, but associated conditions and other causes must be considered. RECENT FINDINGS: Recent data suggest that neonatal diabetes is more common than previously thought, with variable presentations. Continued studies provide further evidence for amelioration of developmental and neurological dysfunction exhibited by a significant proportion of patients. Abnormalities of chromosome 6q24 remain the most common cause of transient neonatal diabetes. Other causes of neonatal diabetes being studied include mutations in proinsulin, FOXP3 mutations in immunodysregulation, polyendocrinopathy, enteropathy, X-linked syndrome, homozygous glucokinase mutations, and Wolcott-Rallinson/EIF2AK3 diabetes. SUMMARY: We still have much to learn about the different forms of neonatal diabetes, their associated clinical features, and the optimization of therapy using a growing number of available therapeutic agents.