Cirilo Sotelo-Avila

Maldescent of the Thymus: 34 Necropsy and 10 Surgical Cases, Including 7 Thymuses Medial to the Mandible

Among 3236 pediatric necropsies over 23 years, abnormal position of thymic tissue was recorded in 34 cases. Cardiac anomalies, predominantly those seen in DiGeorge syndrome, were present in 24; 3 had noncardiac anomalies only, 4 had other diseases, and 3 were sudden infant deaths. Mediastinal thymic tissue was absent in 22 cases, small or unilateral in 7, and normal in 5. The maldescended thymic tissue was unilateral in 18, bilateral in 11, and multiple on one or both sides in 5. It was situated near the thyroid gland in 19, lower in the neck in 6, and higher in 9, including 7 medial to the submandibular salivary gland and 1 at the base of the skull. The maldescended tissue approached the size of a normal lobe of thymus in eight and was 2.4 to 0.1 cm in the remainder. Over the same period, in only two cases was no thymic tissue found. Among 68,000 surgical specimens over 40 years, there were 10 cases of ectopic thymus in the neck, including 1 cutaneous and 4 cystic. This frequency of thymic tissue in the neck may explain why lymphoid tissues are sometimes relatively normal in cases of absent mediastinal thymus and behooves a search in the submandibular salivary gland region and higher before diagnosing thymic agenesis.

Changing spectrum of cholelithiasis and cholecystitis in infants and children

Cholecystitis and cholelithiasis are infrequent in children and have been historically associated with adolescent pregnancy or hemolytic disorders; however, the incidence and spectrum of cholelithiasis seem to be changing. Between 1970 and 1988, 47 children 17 years of age or less underwent cholecystectomy for cholecystitis or cholelithiasis in our hospital. The patients were divided into chronologic groups: Group 1 encompassed 1970 through 1979 (15 patients) and group 2, 1980 through 1988 (32 patients). The groups were compared for age, sex, pregnancy, blood dyscrasia, family history, obesity, use of total parenteral nutrition (TPN), and incidence of choledocholithiasis with its sequelae. A significant increase in the number of patients with cholelithiasis was found. Infants and young children were affected more frequently in group 2, and many of these young patients had a history of TPN. Choledocholithiasis was also more common in group 2 and presented with life-threatening sequelae. Calculous biliary tract disease should be considered as a possible cause of abdominal pain in children. Timely operative intervention can prevent the increasingly common sequelae of childhood cholelithiasis.

Malignancy associated with ureterosigmoidostomy: Detection by mucosa ornithine decarboxylase

Urinary diversion into the gastrointestinal tract (ureterosigmoidostomy) is associated with stepwise malignant degeneration of colonic mucosa. Early detection of such malignancy can be difficult. Ornithine decarboxylase (ODC) is an enzyme that initiates polyamine synthesis that is elevated in malignant colonic mucosa, but its level in premalignant mucosa after ureterosigmoidostomy is unknown. Ten Wistar rats underwent urinary diversion (bladder trigone to sigmoid colon), and were maintained on a regular diet with antibiotics for 6 months, then killed. All animals developed metaplastic changes histologically at the anastomosis. Mean ODC levels of colonic mucosa at the anastomosis v normal colon 8 cm proximal were 515 +/- 177 pmole v 24.5 +/- 4.4 (P less than .01). These data show that premalignant changes in colonic mucosa after ureterosigmoidostomy can be detected by elevated colonic biopsy ODC levels. Periodic sigmoidoscopy with colon mucosa biopsy for histology and ODC levels in children with ureterosigmoidostomy is recommended.

Rhabdomyomatous Mesenchymal Hamartoma Presenting as a Skin Tag in the Sternoclavicular Area

Rhabdomyomatous mesenchymal hamartoma (RMH) is a rare congenital lesion of the dermis and subdermis. It has been described predominantly in newborns, with 30 cases reported in the English literature. Typically, it appears as a skin tag, papule, nodule or a mass involving the face or sternal notch. A 28-day-old girl presented with a 1.4×0.8 cm soft skin tag in the right sternoclavicular area. Physical examination revealed no congenital anomalies. A shaved biopsy showed that the core of the lesion contained striated muscle fibers mixed with hair follicles and sebaceous and eccrine glands. Thin epidermis lined the outside of the tag. We report a patient with a RMH in a site not previously reported and discuss the differential diagnosis.

Renal medullary carcinoma in a six-year-old boy with sickle cell trait

Renal medullary carcinoma (RMC), an aggressive malignant epithelial neoplasm, first emerged as a distinct clinicopathologic entity in 1995. It affects individuals 40 years of age or younger and is strongly associated with sickle cell disease or trait. The majority of patients with RMC have widely disseminated disease at the time of diagnosis and most fail to respond to both chemotherapy and radiotherapy. Mortality approaches 100%, and death usually occurs within a few months to a year of diagnosis. We report a 6-year-old African-American boy with a history of gross hematuria who died four weeks after diagnosis of disseminated metastatic disease. Autopsy showed a 4.4-cm renal mass with metastases to the contra lateral kidney, liver, lungs and multiregional lymph nodes. RMC should be included in the differential diagnosis of any patient 40 years old or younger with a history of hemoglo-binopathy and gross hematuria and/or abdominal or flank pain. A brief discussion of the differential diagnosis, histogenesis and treatment is presented in this study.

Placental pathology for the surgical pathologist.

Summary: Pathologic examination of the placenta is of clinical importance in the evaluation of pregnancies with a less than perfect outcome. Morphologic alterations of the placenta can mirror disorders of the fetus and the mother and evaluation of the placenta can identify clinically significant lesions, allow understanding of a childs disability and may have a role in resolving medical‐legal disputes. Pathologic findings in the placenta can provide information on the pathogenesis of cerebral palsy, mental retardation, or neurodevelopmental disorders. This review will cover a variety of frequently encountered, clinically important, and morphologically distinct disorders of the placenta. The current understanding of the clinical implications of lesions for the mother, infant, and for future pregnancies will also be considered.

Sonography of the Zellweger syndrome.

Case 1 A 6-day-old white infant girl was transferred to Cardinal Glennon Childrens Hospital for evaluation of dysmorphism. She was born to a G2, P2, AbO, mother by spontaneous vaginal delivery. The parents were not consanguineous and another sibling was normal and healthy. Her birth weight of 2050 g placed her below the 5th percentile. Her estimated gestational age was 36 weeks by Dubowitz, but 39 weeks by date. Head circumference was 325 em (50th percentile) with a wide and full anterior fontanelle (4 X 4 em) and separated sutures. She had narrow palpebral fissures and demonstrated hypertelorism. Her ears were low set and her skin was icteric, coarse, and wrinkled. There was no organomegaly. She had large labia minora, a prominent clitoris, and an imperforate anus with an anterior perineal-vagino-rectal fistula. Her extremities dem~ onstrated a left simian crease, bilateral clinodactyly and bilatA era] club feet. Neurological examination revealed hypotonia, absent Moro and gTasp reflexes, and a poor sucking reflex. A skeletal survey demonstrated irregular calcifications in and around both patellae, a small focus of calcification in both greater trochanters, in the left triradiate cartilage and in the left

The hematocrit of reconstituted blood for exchange transfusion in newborn infants

FRESH WHOLE BLOOD has been used for exchange transfusion because, as compared to the use of packed red cells, the greater amount of plasma (albumin) allows removal of more bilirubin. However, in the past decade two changes have altered this situation: the survival of smaller and sicker infants and the increased availability of blood components. Modern therapy now requires keeping a newborn infants hematocrit above certain levels depending on gestational age and clinical condition, l At least two reasons are give n for these recommendations. (1) Compared to adults, the newborn infant has an increased metabolic rate which may be further augmented by prematurity or illness. 2 A low Hct may therefore be insufficient to meet the metabolic oxygen requirements. (2) Anemia may decrease pulmonary vascular resistance, exacerbate left-to-right shunts, and contribute to congestive heart failure in infants with congenital heart disease? Most of a neonates blood is replaced by the transfused blood during the standard double blood volume ET. Thus, the infants Hct immediately following this procedure closely approximates the Hct of donor blood. The Hct of FWB may vary from 32.5 to 48.5% and will, therefore, often be too low for ET. The Hct of PRC may also vary from 55 to 80% or more, depending on the method used to prepare this component (upright sedimentation vs centrifugation vs red cell washing) and will often be too high for ET. However, PRC can be reconstituted with fresh frozen plasma to achieve a desired Hct. We have devised and tested a mathematical formula which allows blood bank technologists to reconstitute PRC with FFP to achieve a desired Hct. METHODS The pediatrician doing the ET specifies the desired Hct of the reconstituted blood. The blood bank technologist then measures the volume (weight) and Hct of the PRC, inserts these values into the following formula, and calculates the volume (weight) of FFP to add to obtain the desired Hct:

THIS ARTICLE HAS BEEN RETRACTED: Acalculous candidal cholecystitis after pediatric renal transplant

Grosser J, Solomon H, Sotelo‐Avila C. Acalculous candidal cholecystitis after pediatric renal transplant.
Pediatr Transplantation 2011: 15: E71–E75.

Mucosal proliferation characteristics in ureterosigmoidostomy: Effect of calcium supplement

Ureterosigmoidostomy, frequently performed in children for urinary diversion, is a known premalignant condition. Dietary calcium supplements have been shown to normalize mucosal proliferative patterns in other human premalignant colonic conditions, which might decrease the risk of cancer. However, calcium supplementation has not been investigated in ureterosigmoidostomy. We used a rat model to study the effects of increased dietary calcium on the progression to carcinoma in ureterosigmoidostomy. Twenty-five Wister rats underwent ureterosigmoidostomy by anastomosis of bladder trigone and ureters to sigmoid, and were divided into two groups: group 1, regular diet (14); and group 2, calcium supplemented (2%) diet (11). All animals received the diet for 9 months. At death the anastomosis was weighed and examined histologically. In addition, ornithine decarboxylase (ODC), an enzyme involved in polyamine synthesis that becomes elevated in neoplastic and proliferative disorders, was determined at the anastomosis and 8 cm proximal (normal colon). All animals developed proliferative metaplastic polyposis at the anastomosis. Tumor weights were 2.6 +/- 1.1 g for group 1 and 4.8 +/- 1.2 g for group 2 (P less than .05). The ODC levels were: group 1, normal colon 78.2 +/- 15.6 and tumor 321.3 +/- 58.8 (P less than .002); and group 2, normal colon 425.8 +/- 65.4 and tumor 568.0 +/- 40.9 (P = NS). The difference between group 1 normal colon and group 2 normal colon was significant (P less than .001), as was group 1 tumor and group 2 tumor (P less than .02).(ABSTRACT TRUNCATED AT 250 WORDS)