Cell-free DNA (cfDNA) analysis may provide a non-invasive diagnostic approach for lung adenocarcinoma patients. Recently, droplet digital PCR (ddPCR) has been developed as a highly sensitive detection method for a low mutant allele percentage. The ddPCR detection limit for epithelial growth factor receptor (EGFR) mutations was evaluated using cell lines, NCI-H1975 for EGFR L858R point mutation and PC-9 for EGFR E746-A750del. Subsequently, detection of EGFR mutations by ddPCR was performed in tumor DNA (tDNA) and cfDNA samples of 19 lung adenocarcinoma patients whose tumor biopsies were already evaluated for EGFR mutations by clamp PCR (13 of L858R, 3 of E746-750del, and 3 of EGFR negative). In 12 cases, immunohistochemical analysis was performed to quantify the number of EGFR L858R-positive cells rate. EGFR point mutation or deletion were detected in 16 tumor DNA samples. In the measurable cfDNA samples, the rate of detection by ddPCR in cfDNA was 61.5% (8/13) for L858R and 100% (3/3) for E746-A750del. A relative correlation was found between the allele fraction (AF) of tDNA and the number of EGFR L858R-positive cells rate. No correlation was found between the AF of tDNA and AF of cfDNA. In our study, cfDNA mutation detection was not associated with clinicopathological features, but cases with high AF of cfDNA did have metastatic lesions. Our study shows that ddPCR enables cfDNA analysis for EGFR L858R and E746-A750del, with a high detection rate. Therefore, cfDNA analysis using ddPCR may complement to tumor biopsy and is beneficial for precision medicine in lung adenocarcinoma patients.

Objective: There is no guideline for the treatment of neonatal ovarian cysts. The present study analyzed our clinical management of such cysts, as well as the results of treatment.

Methods: The present study involved 16 patients with neonatal ovarian cysts who had been diagnosed and treated between January 2002 and December 2016. We classified the cysts into two groups based on ultrasonographic images: (1) simple cysts (SCs)—thin-walled, round, or anechoic; (2) complex cysts (CCs), containing fluid-debris level, solid masses, or intracystic septa. We analyzed the clinical characteristics and results in the two groups.

Results: Ten of the patients had SCs and six had CCs. Fourteen were diagnosed during the prenatal stages. Of the 10 patients with SCs, eight were managed using observation only, and the cysts spontaneously resolved in all such cases. Six patients had CCs, including one with an SC that had developed into a CC. Eight of the patients underwent surgical treatment, and the surgical methods did not differ in terms of operation time or complication rate. None of the oophorectomy specimens contained any normal ovarian tissue.

Conclusion: We operated on all CCs and on SCs more than 40 mm in diameter, while patients with SCs less than 40 mm in diameter were managed using observation only, as were those in whom differential diagnosis was not possible. We must emphasize that percutaneous aspirations are safe, and we recommend transumbilical incisions, because they preserve both esthetics and ovarian function.

Background: Gadolinium-enhanced magnetic resonance imaging (MRI) can be used to observe the progression of cerebral infarction, which sometimes mimics malignant brain tumors. While the β2-microglobulin (β2MG) level in blood plasma or cerebrospinal fluid (CSF) is useful for the diagnosis of malignant tumors or degenerative diseases, these results may create confusion regarding a definitive diagnosis, because it is not a specific marker. We present a rare case of symptomatic developmental venous anomaly (DVA), accompanied by transient, irregular, enhanced cerebral lesions and elevated β2MG in the CSF.

Case Description: A 56-year-old woman developed dysarthria and underwent MRI, which revealed a right frontal hyperintense area around a previous lesion on diffusion-weighted imaging (DWI). She was treated based on the tentative diagnosis of an ischemic cerebrovascular event, and symptoms subsided in 3 days. MRI on day 7 revealed an enlargement of the hyperintense area on DWI. Post-gadolinium MRI showed multiple, enhanced patchy areas in the right frontal lobe and an abnormally large vein connected to dilated medullary venules, indicating DVA. Magnetic resonance angiography showed no stenosis or arterial occlusion. The β2MG level in the CSF was elevated at 2,061 μg/l, and a differential diagnosis from malignant tumor was required. However, MRI on day 23 revealed total disappearance of the enhanced lesions and a decrease in the high intensity area on DWI. Considering the clinical course, the DVA was symptomatic because of the perfusion disturbance.

Conclusion: Careful evaluation is necessary when considering the associated pathologies and potential complications of DVA if detected near a gadolinium-enhanced lesion.