Neonatal Respiratory Distress Syndrome

Neonatal Respiratory Distress Syndrome (RDS)

60,000 cases / year in USA with 5000 deaths Incidence is inversely proportional to gestational age The cause is lung immaturity with decreased alveolar surfactant surfactant decreases surface tension first breath is the hardest since lungs must be expanded without surfactant, lungs collapse with each breath

RDS Risk Factors

1) Prematurity by far the greatest risk factor affected infants are nearly always premature 2) Maternal diabetes mellitus insulin suppresses surfactant secretion 3) Cesarean delivery normal delivery process stimulates surfactant secretion

RDS Pathology

Gross solid and airless (no crepitance) sink in water appearance is similar to liver tissue* Microscopic atelectasis and dilation of alveoli hyaline membranes composed of fibrin and cell debris line alveoli (HMD former name) minimal inflammation

Necrotizing Enterocolitis

Incidence is inversely proportional to gestational age approaches 10% with severe prematurity Pathogenesis not fully understood intestinal ischemia inflammatory mediators breakdown of mucosal barrier

Necrotizing Enterocolitis

Sudden Infant Death Syndrome
Definition sudden death of an infant under 1 year of age which remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and review of the clinical history Also called crib death


Epidemology of SIDS
Leading cause of death in USA of infants between 1 month and 1 year of age90% of deaths occur ≤ 6 months age, mostly between 2 and 4 months

Risk Factors for SIDS

Parental Young maternal age (age <20 years) Maternal smoking during pregnancy Drug abuse in either parent Short intergestational intervals Late or no prenatal care Low socioeconomic group Infant Brain stem abnormalities, associated defective arousal, and cardiorespiratory control Prematurity and/or low birth weight Male sex Product of a multiple birth SIDS in a prior sibling Antecedent respiratory infections Environment Prone sleep position Sleeping on a soft surface Hyperthermia Postnatal passive smoking

Pathogenesis of SIDS

Generally accepted to be multifactorial Triple risk model Vulnerable infant Critical development period in homeostatic control Exogenous stressors Brain stem abnormalities, associated defective arousal, and cardio-respiratory control

Diagnosis of SIDS

SIDS is a diagnosis of exclusion Complete autopsy Examination of the death scene Review of the clinical history Differential diagnosis child abuse intentional suffocation

TUMORS

Benign Malignant

BENIGN

Hemangiomas Lymphatic Tumors Fibrous Tumors Teratomas (also can be malignant)

Congenital Capillary Hemangioma

At birth
At 2 years After spontaneous regression

Teratomas

Composed of cells derived from more than one germ layer, usually all three Sacrococcygeal teratomas most common childhood teratoma frequency 1:20,000 to 1:40,000 live births 4 times more common in boys than girls Aproximately 12% are malignant often composed of immature tissue occur in older children

Sacrococcygeal Teratoma

Malignant Tumors Cancers of infancy and childhood differ biologically and histologically from their counterparts occurring later in life. The main differences are: Incidence and type of tumor Prevalence of underlying familial or genetic aberrations Tendency of fetal and neonatal malignancies to regress spontaneously or cytodifferentiate Improved survival or cure of many childhood tumors,

INCIDENCE AND TYPES The most frequent childhood cancers arise in the hematopoietic system (leukemia & lymphoma), nervous tissue (including the central and sympathetic nervous system, adrenal medulla, and retina), soft tissues, bone, and kidney. Histologically, many of the malignant pediatric neoplasms are unique. In general, they tend to have a more primitive (embryonal) These tumors are frequently designated by the suffix -blastoma, for example, nephroblastoma (Wilms' tumor), hepatoblastoma, and neuroblastoma.

Neuroblastomas

Second most common malignancy of childhood Neural crest originadrenal gland – 40 %sympathetic ganglia – 60%In contrast to retinoblastoma, most are sporadic but familiar forms do occurMedian age at diagnosis is 22 months

Neuorblastoma Morphology

Small round blue cell tumorneuorpil formationrosette formationimmunochemistry – neuron specific enolaseEM – secretory granules (catecholamine)Usual features of anaplasiahigh mitotic rate is unfavorableevidence of Schwann cell or ganglion differentiation favorableOther prognostic predictors are used by pathologists and oncologists


Neuorblastoma
*Neuropil **Homer-Wright Rosettes
*
**

Clinical Course and Prognosis

Hematogenous and lymphatic metastases to liver, lungs and bone 90% produce catecholamines, but hypertension is uncommon Age and stage are most important prognostically < 1 year age: good prognosis regardless of stage Amplification of N-myc oncogene present in 25-30% of cases and is unfavorable up to 300 copies on N-myc has been observed Risk Stratification low risk: 90% cure rate high risk 20% cure rate