Respiratory/Cardio Flashcards
Chinese adult presents with cervical lymphadenopathy gets biopsy and shows pleomorphic keratin-positive epithelial cells in a background of lymphocytes. What disease comes to mind and what is it commonly associated with?
Nasopharyngeal carcinoma (squamous cell carcinoma) - malignant tumor of NP; associated with EBV
Most common bug that causes rhinitis (common cold)?
RSV according to uWorld
most common cause of acute epiglottis in immunized and non-immunized children?
H. influenza b
Laryngotracheobronchitis
Croup; inflammation of upper airway; parainfluenza (paramyxovirus) most common cause; presents with hoarse ‘barking’ cough and inspiratory stridor
two major mediators behind pleuritic chest pain from pneumonia?
bradykinin and prostaglandin E2, inflammation of lung parenchyma, every time lung stretches with breathing it irritates the pleura and results in pleuritic chest pain
What are the two most common causes of lobar pneumonia?
Streptococcus pneumoniae (95%) and Klebsiella pneumoniae
lobar pneumonia; commonly caused community acquired pneumonia by streptococcus pneumonia
interstitial (atypical) pneumonia
interstitial (atypical) pneumonia on biopsy
What is the most common cause of interstitial (atypical) pneumonia?
Mycoplasma pneumoniae; typically affects young adults (military recruits/students living in a dormitory); complications include autoimmune hemolytic anemia (IgM) which causes cold hemolytic anemia and erythema multiform; not visible on gram stains due to lack of cell wall
Bug that causes an atypical pneumonia that is seen in veterinarians and farmers and causes a HIGH fever (Q fever)?
Coxiella burnetii
Primary TB
inhalation of aerosolized Mycobacterium tuberculosis; focal caseating necrosis of lower lobe of lung and hilar lymph nodes; foci undergo fibrosis and calcifications and forms ghon complexes; often asymptomatic but has a positive PPD
Primary TB
inhalation of aerosolized Mycobacterium tuberculosis; focal caseating necrosis of lower lobe of lung and hilar lymph nodes; foci undergo fibrosis and calcifications and forms ghon complexes; often asymptomatic but has a positive PPD
Secondary TB commonly arises due to what 2 things?
AIDS and aging; primary TB is usually asymptomatic with a positive PPD; but secondary is symptomatic
primary TB v. secondary TB with area of lung affected?
1 - lower lobes with Ghon complexes
2- apex of the lung (oxygen tension is highest at the apex)
lung biopsy of pt with secondary TB?
caseating granulomas and AFB stain with red acid-fast bacilli
AFB stain with red acid-fast bacilli as seen in secondary TB
What is the most common organ affected by TB in systemic spread?
kidneys; results in sterile pyuria
pulmonary TB; stimulation of CD4 T lymphocytes releasing interferon gamma; form multinucleated Langerhans giant cells; center of the granuloma will be caseating “cheese-like”
pulmonary TB; stimulation of CD4 T lymphocytes releasing interferon gamma; form multinucleated Langerhans giant cells; center of the granuloma will be caseating “cheese-like”
pink PAS+ globules; built up A1AT in hepatic cells in a pt with A1AT deficiency; results in panacinar emphysema; warn pt against smoking
What is the only pneumoconiosis with increased risk for TB?
Silicosis
lung biopsy showing asbestosis bodies; long rod-shaped particles with round brown deposits (iron); seen in asbestosis pneumoconiosis
air sacs of the lung lined by hyaline membrane as seen in ARDS due to alveolar-capillary damage (leaking)