Purpose: There have been needs to improve the sensitivity of liquid biopsy. This report aims to report the analytical and clinical validation of a next-generation sequencing (NGS)–based circulating tumor DNA (ctDNA) assay. Materials and Methods: Analytical validation was conducted in vitro by evaluating the limit of detection (LOD), precision, and specificity for various genomic aberrations. The real-world performance in non–small cell lung cancer (NSCLC) was assessed by comparing the results of AlphaLiquid100 to the tissue-based results. Results: The LODs with 30 ng input DNA were 0.11%, 0.11%, 0.06%, 0.21%, and 2.13 copies for detecting single nucleotide variants, insertions, deletions, fusions, and copy number alterations (CNA), respectively. Quantitatively, single nucleotide variants/insertions and deletions, fusions, and CNAs showed a good correlation (R2=0.91, 0.40, and 0.65; y=0.95, 1.06, and 1.19) to the manufacturer’s values, and per-base specificities for all types of variants were near 100%. In real-world NSCLC (n=122), key actionable mutations in NSCLC were detected in 60.7% (74/122) with the ctDNA assay. Comparative analysis against the NGS-based tissue results for all key mutations showed positive percent agreement (PPA) of 85.3%. For individual genes, the PPA was as high as 95.7% for epidermal growth factor receptor (EGFR) mutations and 83.3% for ALK translocations. AlphaLiquid100 detected drug-sensitive EGFR mutation at a variant allele frequency as low as 0.02% and also identified an EGFR mutation in a case where tissue sample missed. Blood samples collected post-targeted therapies revealed additional acquired mutations. Conclusion The AlphaLiquid100 ctDNA assay demonstrates robust analytical validity, offering clinically important information for NSCLC patients.

Purpose: Circulating tumor DNA (ctDNA) is emerging as a valuable non-invasive tool to identify tumor heterogeneity and tumor burden. This study investigated ctDNA dynamics in metastatic colorectal cancer patients treated with regorafenib. Materials and Methods: In this prospective biomarker study, plasma cell-free DNA (cfDNA) samples obtained at baseline, at the first response evaluation after 2 cycles of treatment, and at the time of progressive disease were sequenced using a targeted next-generation sequencing platform which included 106 genes. Results: A total of 285 blood samples from 110 patients were analyzed. Higher baseline cfDNA concentration was associated with worse progression-free survival (PFS) and overall survival (OS). After 2 cycles of treatment, variant allele frequency (VAF) in the majority of ctDNA mutations decreased with a mean relative change of –31.6%. Decreases in the VAF of TP53, APC, TCF7L2, and ROS1 after 2 cycles of regorafenib were associated with longer PFS. We used the sum of VAF at each time point as a surrogate for the overall ctDNA burden. A reduction in sum (VAF) of ≥ 50% after 2 cycles was associated with longer PFS (6.1 vs. 2.7 months, p=0.002), OS (11.3 vs. 5.9 months, p=0.001), and higher disease control rate (86.3% vs. 51.1%, p < 0.001). VAF of the majority of the ctDNA mutations increased at the time of disease progression, and VAF of BRAF increased markedly. Conclusion Reduction in ctDNA burden as estimated by sum (VAF) could be used to predict treatment outcome of regorafenib.

BACKGROUND: Although surgical resection with chemotherapy is considered effective for patients with advanced gastric cancer, it remains the third leading cause of cancer-related death in South Korea. Several studies have reported that mesothelial markers including mesothelin, calretinin, and Wilms tumor protein 1 (WT1) were positive in variable carcinomas, associated with prognosis, and were evaluated as potential markers for targeted therapy. The aim of this study was to assess the immunohistochemical expression of mesothelial markers (mesothelin, calretinin, and WT1) in gastric adenocarcinoma and their relations to clinocopathological features and prognosis. METHODS: We evaluated calretinin, WT1, and mesothelin expression by immunohistochemical staining in 117 gastric adenocarcinomas. RESULTS: Mesothelin was positively stained in 30 cases (25.6%). Mesothelin expression was related to increased depth of invasion (p = .002), lymph node metastasis (p = .013), and presence of lymphovascular (p = .015) and perineural invasion (p = .004). Patients with mesothelin expression had significantly worse disease-free survival rate compared with that of nonmesothelin expression group (p = .024). Univariate analysis showed that mesothelin expression is related to short-term survival. None of the 117 gastric adenocarcinomas stained for calretinin or WT1. CONCLUSIONS: Mesothelin expression was associated with poor prognosis. Our results suggest that mesothelin-targeted therapy should be considered as an important therapeutic alternative for gastric adenocarcinoma patients with mesothelin expression.

Carcinoma showing thymus-like differentiation (CASTLE) is a rare carcinoma of the thyroid or adjacent soft tissue of the neck with a histologic resemblance to thymic epithelial tumors. Although the fine-needle aspiration (FNA) plays a central role in the initial evaluation of thyroid nodules, few reports about the cytologic findings of CASTLE have been found according to a review of literatures. We report cytologic findings of a case of CASTLE. A 34-year-old woman presented with a 2-month history of sore throat. The FNA showed that the smear was composed of three dimensional clusters and sheets. The tumor cells were round to ovoid with high nuclear : cytoplasmic ratios. The nuclei were vesicular with small nucleoli. There were some tumor cells showing keratinization. Some lymphocytes were found on the background and within clusters. The presence of poorly-differentiated tumor cells with a focal keratinization and a lymphocytic background on the FNA is suggestive of CASTLE.
Female ; Humans

Carcinoma showing thymus-like differentiation (CASTLE) is a rare carcinoma of the thyroid or adjacent soft tissue of the neck with a histologic resemblance to thymic epithelial tumors. Although the fine-needle aspiration (FNA) plays a central role in the initial evaluation of thyroid nodules, few reports about the cytologic findings of CASTLE have been found according to a review of literatures. We report cytologic findings of a case of CASTLE. A 34-year-old woman presented with a 2-month history of sore throat. The FNA showed that the smear was composed of three dimensional clusters and sheets. The tumor cells were round to ovoid with high nuclear : cytoplasmic ratios. The nuclei were vesicular with small nucleoli. There were some tumor cells showing keratinization. Some lymphocytes were found on the background and within clusters. The presence of poorly-differentiated tumor cells with a focal keratinization and a lymphocytic background on the FNA is suggestive of CASTLE.
Female ; Humans

An endocrine mucin-producing sweat gland carcinoma (EMPSGC) is a rare skin tumor that most commonly occurs on the eyelids of elderly women. This tumor is morphologically analogous to endocrine ductal carcinoma in situ and solid papillary carcinoma of the breast. We describe one case of a 51-year-old male with an EMPSGC co-existing with mucinous carcinoma of the eyelid. The tumor was composed of dilated ducts with a smooth border and was partially filled with a papillary proliferation. Tumor cells were uniform, small-to-medium in size, and oval-to-polygonal with light eosinophilic cytoplasm. Nuclei were bland with diffusely stippled chromatin and inconspicuous nucleoli. Tumor cells expressed chromogranin, synaptophysin, estrogen and progesterone receptors, cytokeratin 7, and epithelial membrane antigen.
Adenocarcinoma, Mucinous ; Aged ; Breast ; Carcinoma, Intraductal, Noninfiltrating ; Carcinoma, Neuroendocrine ; Carcinoma, Papillary ; Chromatin ; Cytoplasm ; Eosinophils ; Estrogens ; Eyelids ; Female ; Humans ; Keratin-7 ; Light ; Male ; Middle Aged ; Mucin-1 ; Mucins ; Receptors, Progesterone ; Skin ; Sweat ; Sweat Gland Neoplasms ; Sweat Glands ; Synaptophysin

We describe a case of an infarcted adenomatoid tumor of the epididymis that was challenging to diagnose. A 20-year-old man presented with acute left scrotal pain. He was found to have a 2x1.5x1 cm tumor that was relatively well circumscribed on gross examination. There was a central necrotic area that exhibited gaping spaces and ghost outlines of epithelial cells. The periphery of the necrotic lesion showed focally viable adenomatoid tumor. The majority of the tissue adjacent to the necrosis consisted of granulation tissue, fibroblastic and myofibroblastic proliferation, and neutrophils. The fibroblasts and myofibroblasts showed plump nuclei, often with small nucleoli. No mitotic activity was present. The differential diagnosis for an infarcted adenomatoid tumor includes malignant mesothelioma, inflammatory myofibroblastic tumor, and inflammatory conditions. The key to diagnosing an infarcted adenomatoid tumor is to consider it in the differential diagnosis of any spindle cell tumor with necrosis occurring in the genital tract.
Male ; Humans ; Diagnosis, Differential

We report here on a case of fibrovascular polyp arising in the hypopharynx of a 62-year-old man. Laryngomicroscopic surgery with laser ablation was performed to excise the mass. Histopathologically, the surface of the polyp was covered with mature squamous epithelium. The polyp showed a characteristic lobular proliferation of mature adipose tissue that was separated by myxoid or collagenous connective tissue. Some scattered skeletal muscle bundles were seen in the central portions of the polyp and these bundles were surrounded by a concentric proliferation of the spindle cells; this was reminiscent of Pacinian corpuscles. Regarding their location and the intermingled pattern of proliferating tissues, it is more plausible that the skeletal muscle is a hamartomatous component rather than entrapped, preexisting tissue.

Coccidioidomycosis, which results from inhaling the spores of Coccidioides species, is endemic in the southwestern United States. The primary infection site is the lung, and dissemination of the disease can occur. We report a case of cutaneous coccidioidomycosis in a 79-year-old Korean woman who presented with purpura on both lower extremities, but no pulmonary symptoms and no history of visiting an endemic area. Microscopically, skin biopsy showed multiple aggregates of granulomas in the dermis. Numerous multinucleated giant cells were associated with the granulomas. Mature and immature fungal spherules, which were 20 to 30 micrometer in diameter, were present inside and outside the multinucleated giant cells.
Female ; Humans ; Biopsy

Vascular malformations associated with neoplasms are extremely rare. Herein we report an extraordinary coincidence of arteriovenous malformation (AVM) and gastrointestinal stromal tumor (GIST) in the jejunum. A 44-year-old woman presented with melena and anemia. Abdominal computed tomography revealed a highly vascularized, strong early arterial enhancing soft tissue mass in the jejunum, which was confirmed by angiography to be an AVM supplied by the distal jejunal branch of the superior mesenteric artery. An emergency operation was performed due to active gastrointestinal (GI) bleeding. The resected jejunum showed a protruding, mostly solid subserosal mass. The mass was confirmed to be a spindle cell type GIST and was intermingled with the AVM located in the overlying submucosa and muscularis propria. To our knowledge, this is the first reported case of an AVM associated with a GIST. This case masqueraded radiologically as an AVM alone and presented clinically with GI bleeding.
Female ; Humans