1. If you find thyroid tissue outside of the thyroid/thyroglossal duct path, its metastatic follicular carcinoma. Do a radiolabeled-iodine scan to find the primary.
2. Hyperaldosterone: if aldo is lower when lying down, and increases upon standing, it's physiologic and more likely to be due to adrenocortical hyperplasia which is treated medically with aldactone (spironolactone, inhibits aldo effect in kidney). If the measurements are the same, or lower when standing, it's more likely to be an adenoma which needs to be treated surgically.
3. Duodenal obstruction in a newborn (bilious vomiting, double bubble)
-Complete: duodenal atresia vs annular pancreas
-Partial: duodenal stenosis vs annular pancreas vs malro (c ladds bands). Malro is a super emergency, diagnose with contrast enema or gastrographin upper GI study.
4. Peds surg: 
-Exstophy of the bladder has better outcomes if its fixed within 48 hours of birth
-Nec enterocolitis: IV fluids/nutrition, NPO, antibiotics; indications to go to OR: pneumoperitoneum, air in biliary tract, abd wall erythema
5. Barium can induce an inflammatory response (granuloma formation) in the peritoneal or mediastina cavity if it leaks, leading to peritonitis, ileus, etc. If you're trying to rule out an esophageal tear or worried about a bowel leak (i.e. intussuception reduction <1% risk perforation in good hands), use gastrographin instead. However gastrographin can cause damage to the lungs if aspirated, so in someone with a high aspiration risk, barium is better. Barium also has much better bowel mucosa coating ability and is a better diagnostic agent, gastrographin has more false negatives.
6. Ann Arbor staging for lymphoma:
I: in one LN, +/- local surrounding tissues
II: In multiple LN, same side of diaphragm
III: both sides of diaphragm, + spleen
IV: extranodal mets (liver, BM)
Modifiers:
A: no B symptoms
B: B symptoms
E: extranodal
X: disease >10 cm
S: splenic involvement
7. Lymph node location, drainage differential diagnosis {source}
Submandibular-- Tongue, submaxillary gland, lips and mouth, conjunctivae -- Infections of head, neck, sinuses, ears, eyes, scalp, pharynx
Submental -- Lower lip, floor of mouth, tip of tongue, skin of cheek -- Mononucleosis syndromes, Epstein-Barr virus, cytomegalovirus, toxoplasmosiss
Jugular -- Tongue, tonsil, pinna, parotid -- Pharyngitis organisms, rubella
Posterior cervical -- Scalp and neck, skin of arms and pectorals, thorax, cervical and axillary nodes
-- Tuberculosis, lymphoma, head and neck malignancy
Suboccipital -- Scalp and head -- Local infection
Postauricular -- External auditory meatus, pinna, scalp -- Local infection
Preauricular -- Eyelids and conjunctivae, temporal region, pinna -- External auditory canal
Right supraclavicular node -- Mediastinum, lungs, esophagus -- Lung, retroperitoneal or gastrointestinal cancer
Left supraclavicular node -- Thorax, abdomen via thoracic duct -- Lymphoma, thoracic or retroperitoneal cancer, bacterial or fungal infection. (Thoracic duct drains directly into L supraclavicular node, at junction of L subclavian and L carotid veins. Thoracic duct drains abdomen, L mediastinum; R mediastinum goes to R side.)
Axillary -- Arm, thoracic wall, breast -- Infections, cat-scratch disease, lymphoma, breast cancer, silicone implants, brucellosis, melanoma
Epitrochlear -- Ulnar aspect of forearm and hand -- Infections, lymphoma, sarcoidosis, tularemia, secondary syphilis
Inguinal -- Penis, scrotum, vulva, vagina, perineum, gluteal region, lower abdominal wall, lower anal canal -- Infections or cancers of the leg or foot, STDs (e.g., herpes simplex virus, gonococcal infection, syphilis, chancroid, granuloma inguinale, lymphogranuloma venereum), lymphoma, pelvic malignancy, bubonic plague

8. Nosebleed in a young adult, not anterior: either septal perforation from cocaine abuse or nasopharyngeal angiofibroma

9. You need an FEV1 of at least 800 to have an acceptable pulmonary quality of life (i.e. not dependent on 10L NC oxygen to walk). When considering significant lung resection, like pneumonectomy for central tumor, do a V/Q scan to see how much lung function comes out of what you're about to resect, subtract from FEV1 score. If its much less than 800, it's a no-go for surgery. {chart on normal FEV1 values by age, gender, height} 

10. Common ENT problems that are usually bilateral that present unilaterally in a kid: foreign object; in an adult: cancer.