Kristopher Neal Lewis

A case of Rosai-Dorfman Disease in a pediatric patient with cardiac involvement

Rosai-Dorfman disease (RDD) involves abnormal proliferations of oddly behaving histocytes that are not derived from the Langerhans Cell linage. These collections tend to occur within lymph nodes, with occasional extra nodal presentation. While RDD is a rare entity itself, extra nodal cases are even more so, with even fewer reporting cardiac involvement, and previously only in adults. This report describes the disease in a pediatric patient who had the unique feature of an extra nodal cardiac mass. The patient, who was known to have sickle cell disease, was initially erroneously thought to have acute chest syndrome. Sudden changes in the patients status, including development of 3rd degree heart block, demanded investigation with additional imaging. Chest CT revealed a mass arising from the cardiac interatrial septum and encircling the entire thoracic aorta. Imaging features of Rosai-Dorfman disease are nonspecific, complicating the diagnosis. We present this case with discussion of this extremely uncommon entity. We describe the diagnostic methods, the differential diagnosis, and the treatment options.

A case of clear cell sarcoma of the kidney.

Clear cell renal sarcoma is a rare tumor and comprises 4% of primary pediatric malignant renal tumors. It is known as an aggressive tumor with poor prognosis. Clinically and radiographically, it resembles Wilms tumor. We present a case of a child with an abdominal mass that was diagnosed as clear cell sarcoma of her right kidney.

Pediatric rhabdomyosarcoma at presentation: Can cross-sectional imaging findings predict pathologic tumor subtype?

OBJECTIVE The purpose of the study is to determine whether there are cross-sectional imaging features of pediatric rhabdomyosarcoma that are specific to the different pathologic subtypes of the tumor. MATERIALS AND METHODS Medical records of 14 pediatric patients who were diagnosed with rhabdomyosarcoma were reviewed retrospectively. Patient demographics, including age and sex, as well as final pathologic report were obtained. The initial CT, MRI, or both obtained at presentation, prior to the diagnosis being established, were reviewed by two radiologists. We recorded tumor features including site, size, margins, local extension, and presence of metastases. Presence of calcification, hemorrhage, or necrosis as well as attenuation and heterogeneity of the tumor were also recorded. RESULTS Ten of our fourteen patients were formally diagnosed with the embryonal subtype of rhabdomyosarcoma, while three were found to have the alveolar subtype, and one subtype was poorly differentiated. There was no significant difference in the attenuation and in the heterogeneity of the tumor between the embryonal and the alveolar subtype on CT. CONCLUSION Imaging features at presentation, such as attenuation and heterogeneity, could not correlate to the pathologic subtype of pediatric rhabdomyosarcoma.

Paucity of biliary ducts: A rare etiology of neonatal cholestasis.

We report a case of a newborn with cholestasis that was diagnosed as nonsyndromic Alagille syndrome. The main feature of the disease is a paucity of biliary ducts. There are two known types of the disease: the syndromic type which is associated with other congenital defects and the nonsyndromic type without other anomalies detected at birth. We describe the case and discuss its clinical and radiologic findings. We also discuss the various etiologies of cholestasis that are included in the differential diagnosis.

Daughter cyst sign.

The daughter cyst sign is a specific indicator of an uncomplicated ovarian cyst and pathologically represents a stimulated ovarian follicle. This finding must be differentiated from an ectopic pregnancy in a patient who has the potential to become pregnant. We report an uncomplicated ovarian cyst in a 3-year-old female with McCune-Albright syndrome and precocious puberty mimicking an ectopic pregnancy.

Hyperostosis - an unusual radiographic presentation of Myelodysplastic Syndrome transformed to Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is also referred to non-lymphocytic leukemia in the literature. It comprises about 15% of the childhood leukemia. There are multiple subtypes of AML from M0-M7 with approximately 45% of the cases being M0-M2 and the remaining subtypes being rare. The definitive diagnosis relies on bone marrow biopsy showing bone marrow infiltration with leukemic cells. We describe a rare radiographic presentation of myelodysplastic syndrome (MDS) transformed to AML in an 8 month old boy who presented with a orbital wall fracture, periosteal reaction, and mixed lytic and sclerotic lesions.

Neonatal cranial ultrasound: current perspectives

Ultrasound is the most common imaging tool used in the neonatal intensive care unit. It is portable, readily available, and can be used at bedside. It is the least expensive cross sectional imaging modality and the safest imaging device used in the pediatric population due to its lack of ionizing radiation. There are well established indications for cranial ultrasound in many neonatal patient groups including preterm infants and term infants with birth asphyxia, seizures, congenital infections, etc. Cranial ultrasound is performed with basic grayscale imaging, using a linear array or sector transducer via the anterior fontanel in the coronal and sagittal planes. Additional images can be obtained through the posterior fontanel in preterm newborns. The mastoid fontanel can be used for assessment of the posterior fossa. Doppler images may be obtained for screening of the vascular structures. The normal sonographic neonatal cranial anatomy and normal variants are discussed. The most common pathological findings in preterm newborns, such as germinal matrix-intraventricular hemorrhage and periventricular leukomalacia, are described as well as congenital abnormalities such as holoprosencephaly and agenesis of the corpus callosum. New advances in sonographic equipment enable high- resolution and three-dimensional images, which facilitate obtaining very accurate measurements of various anatomic structures such as the ventricles, the corpus callosum, and the cerebellar vermis. Limited studies have been performed to predict that longitudinal measurements of these anatomic structures might predict the clinical outcome of high-risk preterm newborns. Hemodynamic Doppler studies may offer the potential for early intervention and treatment to