First trimester pregnancy abnormalities may be detected by transvaginal ultrasonography at routine examinations or in cases where abnormal vaginal bleeding is present. Threatened miscarriage is frequently observed in the first trimester, occurring in more than one-third of pregnancies. The advent of high-resolution transvaginal ultrasonography has revolutionized the understanding of the pathophysiology and the management of early pregnancy. This method represents an essential tool for determining the pregnancy viability in cases of threatened miscarriage. An expectant approach in the management of miscarriage could significantly reduce the number of unnecessary evacuations of retained products of conception, depending on the adopted criteria.

Keywords: Miscarriage, Pregnancy abnormalities, Transvaginal ultrasonography

Acalvaria is a rare congenital malformation of unknown pathogenesis characterized by the absence of the flat bones of the cranial vault, dura mater and associated muscles, while the central nervous system is usually preserved. The most accepted physiopathogenic theory suggests the presence of a postneurulation defect with normal placement the embryonic ectoderm. The present report describes neonatal imaging findings of primary acalvaria.

Keywords: Primary acalvaria; Skull defect; Congenital malformation.

Dengue virus infection is endemic in tropical and subtropical areas. Symptomatic dengue infection is classified into dengue fever or dengue hemorrhagic fever with a tendency to develop shock syndrome. Dengue hemorrhagic fever is characterized by hemorrhagic manifestations, thrombocytopenia and increased capillary permeability. Dengue shock syndrome presents findings of dengue hemorrhagic fever with hypotension. Many sonographic findings have been described, including pleural effusion, ascites, gallbladder wall thickening and pericardial effusion. The aim of the present review is to describe sonographic findings and to demonstrate the role of ultrasonography in the assessment of children with suspected dengue hemorrhagic fever.

Keywords: Dengue; Dengue hemorrhagic fever; Dengue shock syndrome; Pleural effusion; Ultrasonography.

Spinal lipomas are rare, accounting for 1% of all spinal tumors and being associated with occult spinal dysraphism in more than 99% of cases. Such lesions are divided into three main types, namely, lipomyelomeningoceles, intradural lipomas, and filum terminale fibrolipomas. The present report describes a case of congenital lumbosacral lipoma associated with cutaneous stigmata of the lumbar dermal sinus type.

Keywords: Occult spinal dysraphism; Congenital dermal sinus; Intradural lipoma; Ultrasonography.

A congenital ranula is a rare cystic malformation seen in the oral cavity. This pseudocyst is normally located in the sublingual space between the mylohyoid muscle and the lingual mucosa. A 24-year-old woman, gravida 3, para 2, at 29 weeks' gestation was referred to our institution because of polihydramnios and large oral mass.

Keywords: Prenatal diagnosis; Ultrasound; Oral tumor; Ranula.