Histo Halo Halo

Question 1

Alveolar epithelial cells

Answer 1

TYPE I PNEUMOCYTES:
-alveolar lining cells
-small nuclei
TYPE II PNEUMOCYTES
-represents some 60% of cells in the lining epithelium
-occupies a much smaller proportiotn (~5%) of the alveolar surface area
-large nuclei
-secrete SURFACTANT
-retain the capacity for cell division and can differentiate into type I pneumocytes if required

Question 2

Clara cells

Answer 2

• “CLUB CELLS”
• in the terminal and respiratory bronchioles, goblet cells are replaced by CLARA CELLS (non-ciliated cells)
• produce one of the components of surfactant (secretoglobulin / Scgb1A1 / CCSP)
• act as STEM CCELLS
• conain enzyme systems which can detoxify noxious substances
• produce protective GAGs and metabolize air-borne toxins

Question 3

Kulchitsky cells

Answer 3

Bronchial cells
Contain electron-dense granules similar to that seen in cells with a known endocrine function
“Represent the cells of origin of small cell lung cancer”
“Enterochromaffin cells”

Question 4

GISTs arise from

Answer 4

Insterstitial cells of Cajal (Scwartz)

“Gastrointestinal Stromal tumor”

Question 5

GISTs are positive for

Answer 5

c-KIT (CD117)
PDGF receptro A
CD34

(-) actin
(-) desmin

Question 6

Gastric neuroendocrine tumors arise from

Answer 6

gastric enterochromaffin-like (ECL) cells

Question 7

small intestinal carcinoid arise from

Answer 7

enterochromaffin cells
(ileum is the predominant site)

Question 8

what tumorsare positive for CD34?

Answer 8

“FaGoD”

Fibrous tumors of the pleura (also CD99; patternless pattern microscopically)
GIST (also c-KIT/CD117 and PDGF receptor A)
Dermatofibrosarcoma protuberans