21 Histopathology

Question 1

Histo features of JNA

Answer 1

Unencapsulated admixture of vascular tissue and fibrous stroma where the vessel walls lack elastic fibers and have decreased to no smooth muscle; mast cells are abundant in the stroma

Question 2

Cell of origin of parotid gland SCCa

Answer 2

Excretory duct cell

Question 3

What feature distinguishes low grade from high grade mucoepidermoid CA

Answer 3

The amount of mucin in the tumor

Question 4

What are the histologic differences b/w a hemangioma and a vascular malformation

Answer 4

Cellular proliferation is characteristic of hemangiomas; vessel dilation is characteristic of vascular malformations

Question 5

What are the histologic features of vascular malformations

Answer 5

Dilated, ectatic vascular channels with a nl endothelial lining and areas of thrombosis

Question 6

What are the typical histologic characteristics of lymphatic malformations

Answer 6

Multiple dilated lymphatic channels lined by a single layer of epithelium

Question 7

What cells are unique to Hodgkin’s lymphoma

Answer 7

Reed-Sternberg cells

Question 8

What are the main histo types of RMS

Answer 8

embryonal, alveolar, pleomorphic

Question 9

What is m/c type of RMS in H&N

Answer 9

embryonal

Question 10

What are the characteristic histo findings of RRP

Answer 10

Exophytic papillary fronds of multilayered benign squamous epithelium containing fibrovascular cores; cytologic atypia, in particular, koilocytotic atypia, is not unusual

Question 11

What test is used to dx IFS

Answer 11

tissue bx

Question 12

What are the histo findings of IFS

Answer 12

Hyphae with tissue invasion and noncaseating granulomas

Question 13

What feature seen on renal bx with EM is pathognomonic for Alport syndrome

Answer 13

basket-weave configuration of the glomerular basement membrane

Question 14

What other test can be useful in dx Alport syndrome

Answer 14

skin bx

Question 15

What histo finding distinguishes cholesteatoma from CHL granuloma

Answer 15

squamous epithelium is present only in cholesteatoma

Question 16

What cell patterns are characteristic of vestibular schwannoma

Answer 16

Antoni A (tightly arranged)
Antoni B (loosely arranged)

Question 17

In which pattern are Verocay’s bodies found?

Answer 17

Antoni A

Question 18

T/F: Tumors with high percent of Antoni A cells relative to Antoni B cells have a better prognostic outcome

Answer 18

False: Outcome is independent of cell proportions

Question 19

How does one differentiate b/w a benign and malignant paraganglioma

Answer 19

There are no clear histologic characteristics of malignancy; malignant lesions are defined by the presence of mets

Question 20

What are the 2 primary cells of paragangliomas

Answer 20

Type I granule-storing chief cells and type II schwann-like sustentacular cells (S-100 +) arranged in a cluster called a Zellballen

Question 21

What are the histo features of BCCa of skin

Answer 21

Clefting, lack of intracellular bridges, nuclear palisading, and peritumoral lacunae

Question 22

What histo characteristic of recurrent BCCa has negative prog significance

Answer 22

Irregularity in peripheral palisade

Question 23

What are the histo features of SCCa of skin

Answer 23

Keratin pearls in well-diff lesions

Poorly diff lesions may require IHC with cytokeratin or vimentin

Question 24

What are the levels defined in Clark’s system

Answer 24

Level I: Epidermis.
Level II: Invasion of basal lamina into the papillary dermis.
Level III: Fill the papillary dermis.
Level IV: Invasion into the reticular dermis.
Level V: Invasion into subcutaneous fat.

Question 25

What are the histopath features of synovial sarcoma of the H&N

Answer 25

Poorly differentiated, high-grade malignant neoplasms arising from pluripotential mesenchymal cells; biphasic cellular pattern containing spindle cells and epithelioid cells; microcalcifications in 30–60%; the existence of monophasic forms, containing either spindle or epithelioid cells, is controversial.

Question 26

What are the classifications of NP CA designated by WHO?

Answer 26

Type I: Well-differentiated, keratinizing SCCA.
Type II: Poorly differentiated, nonkeratinizing SCCA.
Type III: Lymphoepithelioma or undifferentiated.

Question 27

Which of these is characterized by syncytia (fused multinuclear giant cells)

Answer 27

Type III

Question 28

Which of these is m/c in North America? lease common?

Answer 28

M/c is type III 70%

Least common is type II 10%

Question 29

Which of these is not a/w + EBV titers

Answer 29

Type I

Question 30

What histo pattern is characteristic of an olfactory neuroblastoma

Answer 30

Homer-Wright rosettes

Question 31

What histological subtypes of thyroid tumors are a/w increased risk of local recurrence and mets

Answer 31

Tall cell, columnar, insular, solid variant, and poorly differentiated