The purpose of this study was to analyze the cause of hydrops fetalis (HF) among fetal deaths in the central region of Thailand. Autopsy reports diagnosed as HF from 1999 to 2008 at King Chulalongkorn Memorial Hospital were retrieved, and the pathologic findings, clinical information, fetal ultrasonographic studies, and laboratory investigations were reviewed. There were 78 stillborn autopsies during this 10-year period; the mean gestational age was 28 weeks. The causes of fetal hydrops were identified in 88.5%; no cases of immune hydrops were detected. Anemia was the predominant cause of HF (n  =  33; 42.2%): related to homozygous α-thalassemia (n  =  17; 21.8%), twin-twin transfusion syndrome (n  =  8; 10.2%), hemoglobin H (n  =  3; 3.8%), lung hemorrhage (n  =  1; 1.3%), adrenal hemorrhage (n  =  1; 1.3%), and 3 cases of unspecified etiology (3.8%). Other causes of high-output failure included mass lesions resulting in vascular shunting (n  =  2; 2.6%) and 1 case each (1.3% each) of maternal diabetes mellitus, intestinal lymphangiectasia, and Beckwith-Wiedemann syndrome. Causes resulting in low-output cardiac failure were congenital heart disease (n  =  16; 20.5%) and thoracic space-occupying lesions (n  =  7; 9%). The remaining causes included fetal infection (n  =  5; 6.4%), congenital abnormalities suggestive of a chromosomal or genetic basis (n  =  2; 2.6%), and 1 case (1.3%) of placental vascular thrombosis. Nine cases (11.5%) had no identifiable cause. Thus, the most common cause of HF in this series was homozygous α-thalassemia, reflecting the geographic location of this series.

This study from a medical institution shows a somewhat different spectrum of paediatric oral pathology compared with that reported from dental institutions. While some of the lesions may not be treated by dentists, they still need to be aware of these lesions because affected patients can still present initially to a dentist.

Background: Undifferentiated nasopharyngeal carcinoma is a highly malignant tumor with an endemic distribution. Several histologic parameters have been studied to provide prognostic information for patient management. Both proliferation index and microvascular density are commonly determined on such tumors, but the relationship between these two parameters has not been studied fully. Objectives: Determine the association between microvascular density and cellular proliferation in undifferentiated nasopharyngeal carcinoma. Methods: A series of 60 cases were studied in patients of Southeast Asian origin. Cellular proliferation was determined using Ki67 immunostaining, and vessel proliferation using CD31 immunostaining in terms of areas of increased staining (‘hot spots’). Ki67 results were scored on a scale of 0-4+ and CD31 results as a microvascular density/mm2. Results: The mean of the microvascular density was 22/mm2 in the Ki67-negative group (25 cases). In the Ki67- positive group (35 cases), the mean was 35/mm2. The difference between the positive and negative group was statistically significant (p <0.001). Microvascular density significantly increased as the Ki67 score increased (p<0.001). However, the ‘hot spots’ for microvascular density in tissue sections did not correspond to areas of increased cellular proliferation. Conclusion: Pathologists usually determine only one of these two prognostic factors when dealing with undifferentiated nasopharyngeal carcinoma. The proliferation index is suggested because it is easier to perform and can be done on small biopsies not to contain enough surface area for microvascular density determination.

Background: Ectopic cervical thymomas are rare and there are few descriptions of the cytologic findings based on fine needle aspiration. Their appearances can be misinterpreted as either benign or malignant lesions of the thyroid. The authors report such a case occurring in a patient with Sotos syndrome, a genetic disorder characterized by somatic overgrowth and cognitive impairment. Case Report: The patient developed a neck mass that was examined first by fine needle aspiration and then by pathologic examination of the resected specimen. On fine needle aspiration, a diagnosis of papillary carcinoma of the thyroid was favoured, based on the presence of large cohesive sheets of anastomosing papillary tissue fragments with fibrovascular cores. Pathologic examination of the resection specimen showed a thymoma, subtype B3. The cytologic findings correlated with the presence of nuclear palisading of tumour cells around perivascular spaces. Conclusion: To the best of our knowledge, this histologic subtype of thymoma has never been reported in ectopic cervical thymic tissue, nor these particular cytologic findings that can lead to an erroneous diagnosis of thyroid carcinoma. Moreover, this is the first description of thymoma in association with Sotos syndrome.

Pharyngeal hairy polyps are rare lesions that present as a pedunculated mass that may arise from the oropharyngeal or nasopharyngeal regions of the pharynx. The mass has the potential to partially or completely obstruct pathways towards the trachea and/or esophagus resulting in respiratory distress and/or feeding difficulties respectively. They have a predilection for female infants of 6:1 with the vast majority of the cases occurring in the infantile period. We report 5 cases of the hairy polyp in female infants, one of which showed unusual presentation since it was diagnosed at ten months of age.

Maternal floor infarction (MFI) is an unusual, idiopathic placental disorder characterized by deposition of amorphous fibrinoid material along the maternal aspect of the intervillous space. This condition is associated with poor perinatal outcome-in particular, spontaneous abortion-fetal growth restriction, and stillbirth, with a high recurrence rate in subsequent pregnancies. It is unknown whether MFI is a single entity or the common end point of different insults. Most studies have linked MFI to underlying maternal disorders including gestational hypertension, autoimmune disease, and thrombophilia. In contrast, there have been only a few case reports regarding the possibility of a fetal basis for MFI. We report 2 cases of MFI in fetuses who suffered from oligohydramnios as a result of bilateral cystic renal dysplasia. These 2 cases suggest the concept that fetoplacental factors may also play a role in MFI. It is speculated that the mechanism might involve changes in intrauterine hydrostatic pressure gradients.

Maternal floor infarction is a rare and idiopathic placental disorder associated with adverse obstetric outcomes and a high rate of recurrence in subsequent pregnancies. The pathogenesis of maternal floor infarction is unclear but has been linked to diverse underlying maternal conditions, including gestational hypertension/preeclampsia, immune-mediated diseases, and thrombophilia. Few reports link maternal floor infarction to fetoplacental conditions. We report a 34-week, macerated, growth-restricted male fetus for which the placenta showed maternal floor infarction. The umbilical cord showed excessive coiling and a single umbilical artery. These cord changes are postulated to have resulted in increased placental villous resistance and decreased fetal blood flow, creating a hydrostatic pressure gradient between the villous stroma and the intervillous space. The pressure changes could then lead to trophoblast damage and fibrinoid deposition, contributing to the maternal floor infarction in this case.

Both excessively long umbilical cord (ELUC) and fetal thrombotic vasculopathy (FTV) have been associated with adverse perinatal outcomes, in particular, fetal loss and long-term neurological complications. The etiologies of these conditions are unclear and are likely multifactorial. Excessively long umbilical cord has been associated with FTV and fetal demise, with cases generally showing other cord abnormalities and only localized FTV. We report a 37-week male stillborn fetus whose placenta had a 113-cm-long umbilical cord with no other cord abnormalities associated with "massive" FTV (ie, >25% of the placental mass). This case illustrates the unusual occurrence of FTV of such severe extent in association with ELUC leading to fetal demise. This case illustrates that ELUC alone may be enough to predispose the placenta to massive FTV.