Pathologists should have a low threshold for performing FH, SDHB and CK20 IHC when confronted with unclassified eosinophilic RCC or 'oncocytoma' in young patients.

Myo-Inositol (vitamin B8) is widely used in the drug, cosmetic, and food & feed industries. Here, we present an in vitro non-fermentative enzymatic pathway that converts starch to inositol in one vessel. This in vitro pathway is comprised of four enzymes that operate without ATP or NAD supplementation. All enzyme BioBricks are carefully selected from hyperthermophilic microorganisms, that is, alpha-glucan phosphorylase from Thermotoga maritima, phosphoglucomutase from Thermococcus kodakarensis, inositol 1-phosphate synthase from Archaeoglobus fulgidus, and inositol monophosphatase from T. maritima. They were expressed efficiently in high-density fermentation of Escherichia coli BL21(DE3) and easily purified by heat treatment. The four-enzyme pathway supplemented with two other hyperthermophilic enzymes (i.e., 4-α-glucanotransferase from Thermococcus litoralis and isoamylase from Sulfolobus tokodaii) converts branched or linear starch to inositol, accomplishing a very high product yield of 98.9 ± 1.8% wt./wt. This in vitro (aeration-free) biomanufacturing has been successfully operated on 20,000-L reactors. Less costly inositol would be widely added in heath food, low-end soft drink, and animal feed, and may be converted to other value-added biochemicals (e.g., glucarate). This biochemical is the first product manufactured by the in vitro synthetic biology platform on an industrial scale. Biotechnol. Bioeng. 2017;114: 1855-1864. © 2017 Wiley Periodicals, Inc.

Eosinophilic solid and cystic (ESC) renal cell carcinoma (RCC) has recently been described as a potentially new subtype of RCC based upon morphologic and immunohistochemical features. These neoplasms typically demonstrate solid and cystic architecture, and the neoplastic cells contain voluminous eosinophilic cytoplasm with granular cytoplasmic stippling. There is frequently focal immunoreactivity for cytokeratin 20. Although the initial cases all occurred in adult females and had benign outcome, we recently expanded the proposed spectrum of this neoplasm to include pediatric cases, multifocal neoplasms, and a case with hematogenous metastasis. ESC has been postulated to be analogous to a subtype of RCC consistently identified in tuberous sclerosis complex patients, and while previous work has demonstrated loss of heterozygosity at the TSC1 locus and copy number gains at TSC2 in ESC RCC, these genes have not been sequenced in ESC RCC. Using capture-based and amplicon-based next-generation sequencing, we now demonstrate the consistent presence of either TSC1 or TSC2 gene mutations in pediatric ESC RCC (8/9 cases) and adult ESC RCC (6/6 cases). These included a metastatic ESC RCC which had a complete response to mTOR targeted therapy. We also found these mutations in some neoplasms with variant morphology and thus potentially expand the spectrum of ESC RCC. These include one of our adult cases which demonstrated dominant "type 2" papillary RCC morphology and 2 of 3 previously unclassified pediatric RCC with features of ESC RCC minus granular cytoplasmic stippling. We also demonstrate TSC mutations in a case of so-called "oncocytoid RCC after neuroblastoma" with identical morphology and immunoprofile, providing a molecular link between the latter and ESC RCC. In summary, ESC RCC consistently harbors actionable TSC1 or TSC2 mutations, which are infrequently seen in established subtypes of RCC. These findings support TSC1/2 mutation as a molecular marker of ESC RCC, and suggest expansion of the clinicopathologic spectrum to include neoplasms with papillary architecture, occasional cases lacking well-developed granular cytoplasmic stippling, and a subset of RCC with oncocytic features in patients who have survived neuroblastoma.