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Which study(s) should be performed to determine the precise location of separation in vesiculobullous conditions?

A. Hematoxylin and eosin stained tissue sections

B. Polarized light

C. Heat-induced epitope retrieval

D. Electron microscopy

E. Laser microdissection

D. Electron microscopy is an ancillary technique to resolve diagnostic difficulties in human histopathology through examination of ultrastructural findings at the cellular and organelle level, such as meticulous examination of the dermal-epidermal junction to determine the location of separation in vesiculobullous diseases. Immunofluorescence is also helpful. Hematoxylin and eosin stained tissue sections is the standard method of preparation of tissue for light microscopy. Polarized light is used to confirm the presence of polarizable material (i.e., amyloid). Heat-induced epitope retrieval may be necessary for immunohistochemistry of formalin fixed tissue.

You have just seen a male patient that has numerous angiokeratomas and acroparesthesias. To confirm the diagnosis, a biopsy is performed. For optimal tissue preservation of celluar detail, how should the tissue to be submitted to pathology?

A. In formalin

B. In sterile saline

C. In bacteriostatic saline

D. In water

E. In glutaraldehyde

F. In Bouin solution

E. Fixation with glutaraldehyde provides the best structural preservation; unlike formaldehyde, glutaraldehyde is slowly penetrating. Therefore, only very small pieces of tissue are processed (i.e., 0.5–1 mm3 or 2–3 mm2 and thickness of about 0.5 mm). Electron microscopy may also be performed on formalin fixed material from deparaffinizing a wax block. Preservation may be sufficient for diagnostic purposes although results may be variable. Formalin is used for routine tissue fixation. Sterile saline is often used to submit tissue for microbiology studies. Bouin solution may be used to help tissue dyes adhere.

Which description matches the ultrastructural appearance of a patient with a brown macule that hives when stroked?

A. Rod- and/or racquet-shaped cytoplasmic granule

B. Homogenous dense core cytoplasmic granule

C. Organized subepidermal plaque between 2 cells associated with keratin

D. Organized subepidermal plaque between 1 cell and the dermis

E. Scroll-like structure of granule

F. Fibers with periodicity of approximately 70 nm and aligned in a parallel manner


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