Answer: Squamous-cell carcinoma,
Criteria for diagnosis clinically: An
eroded, poorly circumscribed plaque covered by scales is consonant
with squamous-cell carcinoma.
Differential diagnosis clinically: This
could be an example of long-standing allergic contact dermatitis
that has been excoriated or even of a process infectious, such as
one induced by an atypical mycobacterium. Biopsy is requisite for
coming to a diagnosis with specificity.
Criteria for diagnosis
histopathologically: A small neoplasm with the
silhouette of a malignant process that extends throughout much of
the dermis and is made up of strikingly abnormal keratocytes, many
of them acantholytic and dyskeratotic, in company with numerous
clusters of dyskeratotic cells, as well as with parakeratosis, is a
Differential diagnosis histopathologically:
There is none.
Clinicopathologic correlation: The plaque
is formed by the sheet of neoplastic cells; the scale is a
manifestation of parakeratosis; and the slightly reddish cast is a
consequence of venules in the vicinity of the neoplasm, in
vivo, having been dilated widely and filled with
Options for therapy predicated on knowledge of
histopathologic findings: This squamous-cell
carcinoma, ill-defined clinically, must be removed in
toto by a surgical method, one consideration being the
Mohs micrographic technique, for the purpose of preserving as much
of the lower part of the ear as possible.
1) Although clinically the lesion is a plaque, it appears
histopathologically as a nodule that cuts a swath through the
dermis to about the level of the subcutaneous fat. That seeming
disparity between the appearance clinical and the one
histopathologic is a consequence of the neoplasm having been
sectioned along the short axis of it.
2) Because this squamous-cell carcinoma is typified by
acantholytic dyskeratotic cells, the inference may be drawn that at
a stage very superficial it took the form morphologic of a solar
keratosis. In fact, in a locus there are findings histopathologic
of solar keratosis. In short, a solar keratosis is nothing other
than a superficial squamous-cell carcinoma of one type,
characterized often by suprabasal clefts above which there are
acantholytic dyskeratotic cells.
3) The moderately dense patchy infiltrate of lymphocytes in the
immediate vicinity of the neoplasm is a finding expected in many a
4) Note that this squamous-cell carcinoma on an ear has
obliterated vellus hair follicles, they being noted in normal
number at the periphery of it.
5) Much of the dermis has been replaced by elastotic material,
it representing the effects of decades of damage to the skin by