Kazuhiro Kobayashi

AIM: This study aimed to evaluate the CT and MRI features of ovarian mucinous tumors associated with mature teratomas. MATERIALS AND METHODS: The present study enrolled a total of 34 patients with histopathologically proven ovarian mucinous tumors associated with mature teratomas, including collision tumors composed of mucinous tumors and mature teratomas and mucinous tumors arising from mature teratomas. All patients underwent preoperative pelvic CT and/or MRI. Imaging findings were retrospectively reviewed. RESULTS: Histopathological diagnosis of mucinous tumors included mucinous cystadenoma in 22 patients, mucinous borderline tumor (MBT) in 10 patients, and mucinous carcinoma in two patients. The mean maximum tumor diameter was 168 mm (range, 39-314 mm). All tumors were unilateral, well-defined, predominantly cystic, and multilocular. A total of 14 tumors (41 %) had fewer than 10 loculi, while 12 tumors (35 %) had 30 or more. Fatty components were observed in 30 tumors (88 %), and 20 of 30 tumors (67 %) had multiple fatty components. On MRI, stained glass appearance was observed in 20 of 29 tumors (69 %). On CT, nodular calcifications within fatty components were observed in 12 of 21 tumors (57 %), whereas flattened calcifications within the septa of non-fatty components were observed in 7 of 21 tumors (33 %). Pseudomyxoma peritonei (PMP) was observed in three patients (9 %) with MBT. CONCLUSIONS: Ovarian mucinous tumors associated with mature teratomas typically presented as large, multilocular cystic lesions with fatty components and teratoma/mucinous tumor-associated calcifications. Although PMP was uncommon, it was rarely observed in patients with MBT.

PURPOSE: This study aimed to compare the differences in the imaging findings for dedifferentiated liposarcoma (DDLS) and myxoid liposarcoma (MLS). METHODS: The study included 30 patients with histopathologically confirmed DDLS and 13 patients with MLS. All DDLSs and MLSs were diagnosed immunohistochemically using MDM2 and DDIT3 staining, respectively. Conventional MRI, CT, and 18F-fluorodeoxyglucose-positron emission tomography/CT findings were retrospectively evaluated and compared between the 2 pathologies. RESULTS: The median age of patients with DDLS was higher than that of patients with MLS (74 vs. 46 years, P < 0.01). In 10 DDLSs and 7 MLSs with fatty areas, the well-differentiated liposarcoma-like fatty areas were more common in DDLS than in MLS (70% vs. 14%), whereas septal/linear fatty areas were less common in DDLS than in MLS (30% vs. 86%, P < 0.05). The T2-hyperintense area of non-fatty area was less common in DDLS than in MLS (50% vs. 92%, P < 0.05), and the tumor-to-muscle signal intensity ratio of non-fatty areas on T2-weighted images was lower in DDLS than in MLS (3.18 vs. 5.92, P < 0.01). Apparent diffusion coefficient value was lower in DDLS than in MLS (1.29 vs. 2.10 × 10-3mm2/sec, P < 0.01). Unenhanced CT attenuation of non-fatty area was greater in DDLS than in MLS (33 vs. 19 Hounsfield unit, P < 0.01). CONCLUSION: MRI features are valuable in differentiating MLS from DDLS. Younger age, septal/linear fatty areas, and high signal intensity of non-fatty areas on T2-weighted images were useful for diagnosing MLS.

The histological classification of gastric adenocarcinoma influences its prognostic outcomes and therapeutic strategies. Although fibroblast growth factor (FGF)10 is important for gastric morphogenesis, its use as a molecular marker of gland-forming differentiation pattern remains undefined. The present study examined 117 surgically resected gastric adenocarcinoma specimens using immunohistochemical analysis to evaluate the expression of FGF10 and FGF receptor 2 (FGFR2). Expression patterns in tumor cells and the surrounding stroma were assessed using a four-tier scale. Associations between marker expression and histological differentiation were analyzed by multivariable ordinal logistic regression, adjusting for age, human epidermal growth factor receptor 2 and epidermal growth factor receptor status. Elevated FGF10 expression was significantly associated with well-differentiated, gland-forming histological subtypes, particularly in moderately differentiated tubular adenocarcinoma [adjusted odds ratio (OR) in tumor cells: 1.749, 95% confidence interval (CI) 1.231-2.487, P=0.002; adjusted OR in stroma: 2.418, 95% CI 1.123-5.206, P=0.024]. Conversely, FGFR2 expression showed no association with differentiation pattern (adjusted OR: 0.908, 95% CI 0.452-1.824, P=0.788). Survival analysis revealed no significant relationship between FGF10 or FGFR2 expression level and overall patient survival [hazard ratio (HR) for FGF10 in tumor cells: 0.823, 95% CI 0.640-1.057, P=0.127; HR for FGF10 in stroma: 0.675, 95% CI 0.385-1.183, P=0.170; HR for FGFR2 in tumor cells: 1.080, 95% CI 0.559-2.085, P=0.819]. FGF10 may thus be a promising molecular marker of gland-forming differentiation pattern in gastric adenocarcinoma, offering valuable insights for refining its histopathological classification. These findings may contribute to the development of stratification biomarkers for personalized therapeutic approaches, particularly for the selection of molecular-targeted therapies. The absence of an association with overall survival, however, highlights the need for further investigations into the underlying mechanisms and their broader clinical significance.