BACKGROUND: A lot of congenital melanocytic nevi (CMN) carry the somatic mutation in the oncogene BRAF V600E. But the detailed histopathologic characteristics and the proliferative activity of CMN with BRAF V600E gene mutation have not been systematically documented.
OBJECTIVE: To identify the proliferative activity and histopathological features correlating them with BRAF V600E gene mutation status in CMN.
METHODS: CMN were retrospectively identified from the laboratory reporting system. Mutations were determined by Sanger sequencing. The CMN were divided into a mutant group and control group according to whether there was BRAF gene mutation and were strictly matched according to gender, age, nevus size, and location. Histopathological analysis, analysis of Ki67 expression by immunohistochemistry and laser confocal fluorescence microscopy were performed.
RESULTS: The differences in Ki67 index, the depth of nevus cell involvement and the number of nevus cell nests between the mutant group and the control group was statistically significant, with p-values of 0.041, 0.002 and 0.007, respectively. Compared with BRAF V600E negative nevi, BRAF V600E positive nevi often exhibited predominantly nested intraepidermal melanocytes, and larger junctional nests, but the difference in this data sets were not statistically significant. The number of nests (p = 0.001) was positively correlated with the proportion of Ki67 positive cells.
CONCLUSIONS: A small sample of patients were included and there was no follow-up.
CONCLUSIONS: BRAF V600E gene mutations were associated with high proliferative activity and distinct histopathological features in congenital melanocytic nevi.

A novel endophytic actinomycete, designated strain LD22T, was isolated from moss [Physcomitrium sphaericum (Ludw) Fuernr] collected from Yunnan Province, Southwest China. A polyphasic taxonomic study was carried out to establish the status of this strain. Morphological and chemotaxonomic characteristics of strain LD22T confirmed the affiliation of the isolate to the genus Actinomadura. The diamino acid present in the cell wall is meso-diaminopimelic acid. Glucose, madurose, galactose and ribose occur in whole cell hydrolysates. The menaquinones were identified as MK-9(H4), MK-9(H8), MK-9(H6) and MK-9(H2). The polar lipid profile was found to contain diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified phospholipid. The major fatty acids were found to be C16:0, 10-methyl C18:0 and C18:1 ω9c. The DNA G + C content of the draft genome sequence, consisting of 10.0 Mbp, was 72.5%. Phylogenetic analysis of 16S rRNA gene sequences showed that strain LD22T belongs to the genus Actinomadura with the highest sequence similarity to Actinomadura montaniterrae CYP1-1BT (99.2%). However, phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate formed a phyletic line with Actinomadura rudentiformis HMC1T (98.6%). The low level of DNA-DNA relatedness and some different phenotypic characteristics allowed the strain to be distinguished from the above-mentioned two strains. Therefore, it is concluded that strain that strain LD22T represents a novel species of the genus of Actinomadura, for which the name Actinomadura physcomitrii sp. nov. is proposed. The type strain is LD22T (= CCTCC AA 2018050T = JCM 33455T).

BACKGROUND: Choroid plexus papillomas (CPPs) are rare benign tumors, and the pigmented subtype is observed even more rarely.
METHODS: We present the case of a 43-year-old woman with complaints of headache and progressive left monocular visual deterioration, whose initial plain computed tomography CT scan showed an ovate high-density tumor located within the insellar region. Magnetic resonance imaging revealed a homogeneously contrast-enhancing tumor extending from the sella turcica to the suprasellar cistern. Single-nostril transsphenoidal endoscopic resection followed by subfrontal subtotal resection was performed in this patient. Postoperative histology revealed that the tumor consisted of hyperchromatic tissue with papillary features. Higher-resolution examination of the tissue revealed this tissue was composed of hyperplastic columnar epithelial cells with hyperchromatic cytoplasmic pigment. Subsequent immunohistochemistry identified the lesion as a pigmented choroid plexus papilloma. Here we review the current literature, discuss the origin of the tumor, the differential diagnosis, and the roles of surgery and radiotherapy.
CONCLUSIONS: This case study provides important clinical information for the evaluation, diagnosis, and treatment of pigmented CPP in the sellar region.