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Discussion Starter · #1 ·
Hey,guys.Here is a question from Robbins Reviews of Pathology.I can't understand why the answer B is ruled out in the corret answer.Could anyone give me a hand?Thanks a lot!

A 55-year-old man has had a foot ulcer for 2 months
that has not healed. Physical examination shows a 2-cm shallow,
nonhealing ulceration of the left medial malleolus. There
is symmetric decreased sensation in the distal regions of the
lower extremities. He has a history of multiple urinary tract
infections resulting from difficulty in completely emptying the
bladder. He is impotent. Which of the following pathologic
findings is most likely to be present in the peripheral nerves?
A Acute inflammation
B Axonal neuropathy
C Onion bulb formation
D Segmental demyelination
E Wallerian degeneration

D The features described are consistent with a peripheral
neuropathy associated with diabetes mellitus. Both motor
and sensory nerves can be involved, and there may be
an autonomic neuropathy. Histologic examination shows
an axonal neuropathy with segmental demyelination. Difficulty
in emptying the urinary bladder and impotence
are results of autonomic neuropathy. Longer nerves are
affected first; this explains the lower leg involvement and
accounts for many cases of diabetic foot, with trauma and
subsequent ulceration. Acute inflammation is not generally
seen in neuropathies. Lymphocytic infiltrates may be seen
in Guillain-Barré syndrome. Onion bulb formation is a feature
of the hereditary neuropathy known as Refsum disease.
Wallerian degeneration typically occurs with traumatic
transection of a nerve.
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