The placenta plays a central role in governing local circulatory system that mediates maternal condition and fetal growth. In early gestational phases, the placenta exerts properties of invasion and neovascularization for successful placentation. Extravillous invasive trophoblasts replace uterine endometrial vasculature and establish local blood pathway to obtain oxygen and nutrients from the mother. In later phases, the placenta promotes villous angiogenesis and vascular maturation that are finely controlled by angiogenic and antiangiogenic molecules. Among various molecules involved in placental neovascularization, vascular endothelial growth factor receptors (VEGFRs) and angiotensin II receptor type 1 (AT1) mediate important signaling pathways for maternal circulatory system and fetal growth. VEGFR1 and VEGFR2 are functional receptors for placental growth factor (PlGF) and VEGF, respectively, and PlGF-VEGFR1 and VEGF-VEGFR2 interactions are disturbed in many preeclamptic patients by excess amount of soluble form of VEGFR1 (also named sFlt1), a natural PlGF/VEGF antagonist. Recent studies have disclosed that excessive sFlt1 production in the placenta and aberrant AT1 signaling in the mother are closely associated with the pathology of preeclampsia and intrauterine growth restriction (IUGR). In this paper, neovascularization of the placenta and pathological events associated with disrupted balance between angiogenic and antiangiogenic signaling in preeclampsia are discussed.

Background: Although gangliocytic paraganglioma (GP) is considered a rare benign neuroendocrine tumor, cases of mortality have been reported. Occasionally, GP is misdiagnosed as neuroendocrine tumor G1, which is associated with a poorer prognosis than GP. To avoid such misdiagnoses, it is important to understand the clinicopathological characteristics of GP. Thus, herein, we discuss the current literature on the clinicopathological characteristics of GP.Methods: We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. PubMed and Japana Centra Revuo Medicina searches were used to identify papers describing GP. Inclusion criteria included confirmation of epithelioid, spindle-shaped, and ganglion-like cells in the main article and/or figures and whether the paper was cited in other studies of GP. Data were collected on age, sex, site of the primary lesion, tumor size, treatment, prognosis, lymph node metastasis (LNM), depth of tumor invasion, rate of preoperative diagnosis, and clinical symptoms.Results: In total, 162 papers containing 263 cases of GP met the criteria. The mean age at diagnosis was 53.5 years. The male-to-female ratio was 157:104. The mean tumor size was 25.7 mm. The predominant site of the primary tumor was the duodenum (89.7%). The most common clinical sign of GP was gastrointestinal bleeding (47.9%). Other signs and symptoms of GP included abdominal pain (44.7%), anemia (20.3%), incidental findings (12.9%), nausea (6.9%), weight loss (5.5%), general fatigue (5.1%), jaundice (4.6%), and incidental autopsy findings (5.1%). LNM was observed in 11.4% of patients. Liver metastasis was observed in 1.1% of patients. Depth of tumor invasion (penetrating beyond the submucosal layer or sphincter of Oddi) was by far the most significant risk factor for LNM in patients with GP. This suggests, along with histological heterogeneity, that GP may have hamartomatous characteristics. Furthermore, immunohistochemical expression of progesterone receptor and pancreatic polypeptide were useful in distinguishing between GP and neuroendocrine tumor G1, even in small biopsy specimens.Conclusions: We reveal the clinicopathological characteristics of GP, including risk factors for LNM, differential diagnostic approaches, and improvements in the clinical management of this tumor.In addition, GP may have hamartomatous characteristics.

Sebaceous carcinoma (SC) of the breast is a rare malignant tumor and only nine cases, including the present one, have been reported in the English-language literature. The present report describes a case of mammary SC in a 50-year-old Japanese woman. The tumor was gray-white on cut surface and separate from the skin and the nipple. Microscopically, lobules encircled by a fibrous envelope and cords or small cell nests in the stroma were noted. These two types of structures were composed of dark cells and clear foamy cells. The dark cells had large nuclei and amphophilic cytoplasm. The clear foamy cells had numerous lipid vacuoles, confirmed on immunostaining with anti-adipophilin antibody and electron microscopy. In the lobules the gradual transitions from basal dark cells to central clear foamy cells and comedo-like necrosis were observed. The tumor cells were positive on immunohistochemistry for cytokeratins (CAM5.2, AE1/AE3), Her2/neu and androgen receptor but negative for estrogen and progesterone receptors. This is the first case of an androgen receptor-positive mammary SC to be reported, and therefore contributes to the understanding of the clinicopathological features of SC of the breast.

Fetal adenocarcinoma is a rare variant of lung adenocarcinoma, which is subcategorized into low-grade and high-grade forms. High-grade fetal adenocarcinoma confers worse prognosis than low-grade fetal adenocarcinoma, but the prognostic differences between high-grade fetal adenocarcinoma and conventional lung adenocarcinoma are unknown. We reviewed tissue sections of 3719 cases of surgically resected primary lung cancers and found 53 lung cancers with a high-grade fetal adenocarcinoma component. We analyzed their clinicopathological and immunohistochemical features, and performed a prognostic analysis of adenocarcinomas with the fetal-type component. We further analyzed the prognostic differences between adenocarcinomas with the fetal-type component and conventional adenocarcinomas without the fetal-type component. Lung cancers with the fetal-type component predominantly occurred in elderly men with a smoking history. Twenty-nine patients had stage I disease, 13 patients had stage II, and 11 patients had stage III. The fetal-type histology was combined with conventional-type adenocarcinoma (41 cases), squamous cell carcinoma (5 cases), large cell neuroendocrine carcinoma (5 cases), enteric adenocarcinoma (2 cases), and small cell carcinoma (1 case). The fetal-type component showed immunopositivity for α-fetoprotein (39%), glypican-3 (37%), and SALL4 (17%). The 5-year overall survivals of fetal-type-predominant and fetal-type-nonpredominant patients were 44 and 56%, respectively (P = 0.962). The 5-year overall survivals of lepidic-, acinar-, papillary-, solid-, and micropapillary-predominant adenocarcinomas, invasive mucinous adenocarcinomas, and adenocarcinomas with the fetal-type component were 94, 82, 77, 69, 57, 83, and 41%, respectively (P < 0.001). Univariate and multivariate analyses showed that adenocarcinomas with the fetal-type component had a significantly lower overall survival rate than the other histological subtypes, except for the micropapillary-predominant subtype. Our study demonstrated that adenocarcinomas with the fetal-type component had a poor prognosis that was comparable to that of micropapillary adenocarcinoma. The presence of the high-grade fetal adenocarcinoma component in lung adenocarcinomas is an important prognostic marker.

Gangliocytic paraganglioma (GP) has been regarded as a rare benign tumor that commonly arises from the second part of the duodenum. As GP does not exhibit either prominent mitotic activity or Ki-67 immunoreactivity, it is often misdiagnosed as neuroendocrine tumor (NET) G1. However, the prognosis might be better in patients with GP than in those with NET G1. Therefore, it is important to differentiate GP from NET G1. Moreover, our previous study indicated that GP accounts for a substantial, constant percentage of duodenal NETs. In the present article, we describe up-to-date data on the clinicopathological characteristics of GP and on the immunohistochemical findings that can help differentiate GP from NET G1, as largely revealed in our new and larger literature survey and recent multi-institutional retrospective study. Furthermore, we would like to refer to differential diagnosis and clinical management of this tumor and provide intriguing information about the risk factors for lymph node metastasis on GP.