"Neuroendocrine Tumor Grade 3 (NET G3)" of the Uterine Cervix: A Report of 2 Cases.

In the fifth edition of the World Health Organization classification of female genital tumors, neuroendocrine neoplasms are subcategorized as neuroendocrine tumors (NETs) of grade 1 (G1) and G2, and neuroendocrine carcinoma. NET G3 is not included, as it is for classification of pancreas tumors. Herein, we report 2 cases of "NET G3" of the uterine cervix with long-term follow-up. The patients are 40- and 36-yr-old women who presented with polypoid masses on the uterine cervix. Microscopic examination of hysterectomy specimens revealed tumor features similar to those of pancreatic NET G3 and intestinal type mucinous carcinoma cells invading the cervical stroma. In both cases, the NET component was positive for synaptophysin and chromogranin A, and negative for TTF-1. Mitotic counts were <1/2 mm 2 and 5/2 mm 2 , and the Ki-67 labeling indexes were 57% and 39%, respectively. Pathologic stage classifications (AJCC, version 9) were pT1b1, pN0, and cM0 (FIGO stage IB1), and both patients received adjuvant therapy. One patient had lung and pancreas metastases 4 to 8 yr after initial surgery, which were surgically removed. Both patients remain alive without evidence of recurrent disease 6 and 16 yr after initial surgery. The indolent clinical courses of these cases appear to indicate that cervical "NET G3" is biologically closer to NET than neuroendocrine carcinoma; thus, including uterine cervical "NET G3" in the classification may be justified. However, the optimal management for this tumor type remains undetermined.

Improved assay for differential diagnosis between Pompe disease and acid α-glucosidase pseudodeficiency on dried blood spots.

The high frequency (3.3-3.9%) of acid α-glucosidase pseudodeficiency, c.[1726G>A; 2065G>A] homozygote (AA homozygote), in Asian populations complicates newborn screening for Pompe disease (glycogen storage disease type II or acid maltase deficiency) on dried blood spots, since AA homozygotes have a considerably low enzyme activity. We observed that hemoglobin in the enzyme reaction solution strongly interferes with the fluorescence of 4-methylumbelliferone released from 4-methylumbelliferyl α-D-glucopyranoside (4MU-αGlc) by acid α-glucosidase. Therefore, we have searched for a method to effectively eliminate hemoglobin in the reaction solution. Hemoglobin precipitation with barium hydroxide and zinc sulfate (Ba/Zn method) carried out after the enzyme reaction considerably enhances the fluorescence intensity while it does not reduce the intensity to any extent as can occur with conventional deproteinization agents like trichloroacetic acid. The Ba/Zn method greatly improved the separation between 18 Japanese patients with Pompe disease and 70 unaffected AA homozygotes in a population of Japanese newborns in the assay with 4MU-αGlc on dried blood spots. No overlap was observed between both groups. We further examined acid α-glucosidase activity in fibroblasts from 11 Japanese patients and 57 Japanese unaffected individuals including 31 c.[1726G; 2065G] homozygotes, 18 c.[1726G; 2065G]/[1726A; 2065A] heterozygotes and 8 AA homozygotes to confirm that fibroblasts can be used for definitive diagnosis. The patients were reliably distinguished from three control groups. These data provide advanced information for the development of a simple and reliable newborn screening program with dried blood spots for Pompe disease in Asian populations.

High frequency of acid alpha-glucosidase pseudodeficiency complicates newborn screening for glycogen storage disease type II in the Japanese population.

To investigate the feasibility of newborn screening for glycogen storage disease type II (GSDII; Pompe disease or acid maltase deficiency) in the Japanese population, we assayed the acid alpha-glucosidase activity in dried blood spots from 715 Japanese newborns and 18 previously diagnosed patients using a fluorometric procedure. The enzyme activity of apparently healthy newborns showed a bimodal distribution. The median activity of the minor group (31 individuals, 4.3% of the samples) was 6.5 times lower than that of the major group. Four of the 715 control samples (0.56%) fell in the patient range. We then analyzed genomic DNA, extracted from the same blood spots, for the occurrence of two sequence variants, c.1726G>A and c.2065G>A, known to cause "pseudodeficiency". This analysis revealed that 27 of 28 individuals homozygous for c.[1726A; 2065A] belonged to the minor group. One c.[1726A; 2065A] homozygote had just slightly higher activity. Twelve of the 18 patients with GSDII either had one (9 cases) or two (3 cases) c.[1726A; 2065A] alleles. The frequency of this allele was double in the patient compared to the control group (0.42 vs 0.19) at the expense of a lower frequency of the c.[1726G; 2065G] and c.[1726G; 2065A] alleles (0.58 vs 0.71 and 0 vs 0.1). These findings illustrate that c.[1726A; 2065A] homozygosity among apparently healthy individuals (3.9 per 100) complicates newborn screening for GSDII in Japan, and further that one or more pathogenic mutations are associated with the c.[1726A; 2065A] allele.