Pathology - part 2

Question 1

sinunitis: cause (child vs. adult)? diagnosis? Rx?

Answer 1

Sinus infection: adult: maxillary (上颌窦）；child: ethmoid (筛骨窦）

MC cause: viral URI (upper respiratory infection) such as Rhinovirus

MC baterial pathogen causing sinusitis: S. pneumoniae

most sensitive diagnosis: CT scan

Rx: decongestants; not recommend antibiotics (viral); if resoluation does not occur: amoxicillin, erythromycin

Question 2

Nasopharyngeal (NP) carcinoma： associated with which virus?

Answer 2

EBV; ↑ in Chinese adults, and African children

> 70% matastasized to cervical lymph nodes

Rx: radiotherapy

Question 3

RDS (respirotary distress syn):

cause?

Answer 3

↓ surfactant (synthesized by type II pneumocytes, begin at 28th wk of gestation)

major component: lecithin

cortisol/thyroxine ↑ synthesis;

insulin ↓ synthesis

Chest X-ray: “ground glass” appearance throughout both lungs

RDS O2 therapy causes complications: blindness, bronchopulmonary dysplasia (superoxide free radical damage)

Question 4

ARDS (acute respirotary distress syn)：cause, patho, lab, Rx？how to distinguish from cardiogenic pulmonary edema?

Answer 4

Cause: sepsis (MCC), gastric aspiration, severe trauma

Patho: acute alveolar-cap. damage; macrophage release cytokines ➞ chemotactic to neutrophils ➞ damage both type I and II pneumocytes

clinic: severe hypoxemia, PA wedge pressue (肺动楔压，代表左房压）< 18 mmHg, ↑ A-a gradient

i_mportant to distinguish from cardiogenic pulmonary edema (PA wedge pressure > 18 mm H_g)

Rx: treat underlying disease, hemodynamic monitor, mechanic ventilation, NO inhalation, corticosteriods

Question 5

Leukemia markers: TdT? Peroxidase?

Answer 5

TdT(+）： lymphoblast (ie. ALL, in children < 6 yr)

• if CD19+/CD10+: precursor B-cell lymphoma
• if CD1+/CD2+/CD5+: precursor T-cell lymphoma

[these 2 types can only be differentiated by immunophenotyping]

Question 6

RS cells: marker for ?

Bcl-2: marker for ?

BCR-ABL rearrangememt?

C-Myc? N-Myc?

Answer 6

Hodgkin’s lymphoma

differentiated from non-Hodgkin’s (ie. follicular lymphoma): aggregates of packed follicles under low magificance, ↑ Bcl-2

CML: BCR-ABL rearrangement t(9:22) Philadelphia chromosome ⇒ CA-PTK, myeloproliferative disorderclinic: splenomegaly; Histo: neutrophils at all different stage of development; basophilia is prominent in CML

C-Myc: Burkitt’s lymphoma (“starry sky”)

N-Myc: neuroblastoma, small cell carcinoma of the lung

Question 7

TB: patho, test, location?

Answer 7

Mycobacterium tuberculosis resides in phagosomes of alveolar macrophages, ⇒ produce cord factor (protein, virulent) that prevents fusion of lysosomes with phagosomes

Screen: PPD intradermal test (do NOT distinguish active vs. inactive TB)

1º TB: upper part of lower lobes, lower part of upper lobes, Ghon complex (tan-yellow subpleural granuloma with caseation necrosis + tan-yellow hilar lymph node with caseation necrosis in the mid-lung field)

2º (reactivation) TB: one or both apices in upper lobes (best ventilation, M. tuberculosis is strict aerobe)

MC extrapulmonary TB site: kidney (adrenal involvement may result in Addison disease)

Question 8

Dx for MM (multiple myeloma)?

Answer 8

≥ 30% plasma cells in BM sample

Plasma cells: abudent basophilic cytoplasma, eccentrically placed nuclei, perinuclear pale zone (well-developed Golgi)

Clinic: anemia, bone resorption (bone pain, fractures), hypercalcemia, ↑ infection, Al amyloidosis (↑↑ Mc Ig light chains -“Bence-Jones protein” in urine is Dx, deposit in kidneys, heart, tougue, CNS)