SIDS And Infant tumors Flashcards
What is SIDS?
•Sudden Infant Death Syndrome (SIDS) is the sudden death of an infant under 1 year of age, which remains unexplained after a thorough case investigation, including the performance of a complete autopsy, examination of the death scene and review of the clinical history.
Causes of death
- NEONATE (0-4 WEEKS): CONGENITAL, PREMATURITY
- UNDER ONE YEAR: CONGENITAL, PREMATURITY/WEIGHT, SIDS
- 1-4 YEARS: ACCIDENTS, CONGENITAL, TUMORS
- 5-14 YEARS: ACCIDENTS, TUMORS, HOMICIDES
- 15-24 YEARS: ACCIDENTS, HOMICIDE, SUICIDE
Epidemiology and facts about SIDS
- 90% of SIDS deaths before 6 months of age
- Most SIDS deaths happen when babies are between 2 months and 4 months of age.
- Seasonal trend: there are more SIDS deaths in winter months.
- More male babies die of SIDS.
- Unaccustomed tummy sleeping increases risk as much as 18-fold.
Morphology of SIDS
•SIDS is a diagnosis of exclusion
•Non-specific autopsy findings
–Multiple petechiae (thymus, pleura, epicardium)
–Pulmonary congestion ± pulmonary edema
(These may simply be agonal changes as they are found in non-SIDS deaths also)
-Histological signs of recent infections in the upper respiratory system
Pathogenesis of SIDS
•Delayed development of “arousal” and cardiorespiratory control theory
•Abnormalities in the serotonin-dependant signaling in the brain stem
•Normally activation of laryngeal chemoreceptors causes inhibition of cardiorespiratory reflex
•Respiratory infections increase activity of Laryngeal Chemoreceptors – hypoxia- death
serotonergic (5-HT) system of the medulla is implicated in “arousal” responses
Common features of pediatric tumors
- Both type of tumors are present: benign and malignant
- Benign tumors in children more common than malignant but do not have statistical impact on mortality rate
- Only 2% of all malignant tumors occur in infancy or childhood
- Pediatric tumors are the second leading natural cause of death under age 14 (accidents are #1)
- Brain tumors and leukemia/lymphoma account for about two-thirds
- Pediatric and adult cancers are different (epithelial origin in adults, mesenchymal origin in children)
Benign tumors
- Hemangiomas
- Lymphatic Tumors
- Fibrous Tumors
- Teratomas (also can be malignant)
•Benign tumor of blood vessels
- Are the most common tumor of infancy
- Two types: cavernous and capillary
- Locations: usually on skin, especially face and scalp
- Irregular red-blue masses (port-wine stains)
- Regress spontaneously in many cases before 5 years old
- Sometimes are part of Von Hippel-Lindau (VHL) disease ( CNS hemangioblastomas, pheochromocytoma, renal cell carcinoma + pancreatic cysts)
Hemangioma
- Benign tumor of blood vessels
- Are the most common tumor of infancy
- Two types: cavernous and capillary
- Locations: usually on skin, especially face and scalp
- Irregular red-blue masses (port-wine stains)
- Regress spontaneously in many cases before 5 years old
- Sometimes are part of Von Hippel-Lindau (VHL) disease ( CNS hemangioblastomas, pheochromocytoma, renal cell carcinoma + pancreatic cysts)
Congenital-infantile fibrosarcoma
Excellent prognosis, that is why it’s here
- A vascular birthmark that is not behaving as expected - it’s growing rapidly; it’s firm; it’s infiltrative, especially in a distal location like the hands or feet
- Result of unique fusion oncogene ETV6-NTRK3 – is an important diagnostic marker
Lymphatic Benign Tumors (Cystic Hygromas)
- Lymphangiomas: cystic or cavernous types, MC location deep regions of the neck, axilla, mediastinum.
- Lymphangiectasis: result in diffuse swelling of part or all extremity
Teratomas
•Composed of cells derived from more than one germ layer, usually all three
•Can be benign (75%), intermediate potential and malignant (12%)
•Two peaks of incidence: 2 years old (mostly benign) and 16-18 years old (mostly malignant)
•Sacrococcygeal teratomas:
–most common childhood teratoma
–4 times more common in boys than girls
Other locations: testis, ovaries, mediastinum, retroperitoneum, neck, head
DIFFERENCES
IN PEDIATRIC CANCER vs ADULT CANCER
- Site of origin different (mesenchymal)
- Type – sarcomas, “blastomas,” small round blue cell tumors
- Bulk typically greater but no cachexia
- Prognosis often better, spontaneous regression, high sensitivity to antineoplastic therapy
- Neonatal tumors – tend to be less aggressive
- Prevalence of familial and genetic aberrations
INCIDENCE AND TYPES of MALIGNANT TUMORS IN CHILDREN
•Children younger than 5 years old:
- Leukemias (Acute Lymphoblastic)
- Brain Tumors (Posterior Fossa Medulloblastomas, Astrocytomas)
- Lymphoma
- Nephroblastoma (Wilms Tumor)
- Neuroblastoma
- Retinoblastoma
- Hepatoblastoma, etc
Histological difference from adult malignant tumors
- Child tumors are not pleomorphic-anaplastic structure but embryonal
- BLASTOMA – A neoplasm composed of embryonic cells derived from the blastema of an organ or tissue [Gr. BLASTOS = germ]
- Primitive neuroectodermal tumors (PNETs) are a group of highly malignant tumors composed of small round cells of neuroectodermal origin that affect soft tissue and bone.