Page 33 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 2-6 Benign Growths

ECCRINE SYRINGOMA

Eccrine syringomas are extremely common benign skin
growths. They are most often found on the lower
eyelids and malar cheek regions of adults. These small
tumors are of no clinical significance and are routinely
ignored in clinical practice.
Clinical Findings: Eccrine syringomas are some of
the most common benign skin tumors to affect human-
kind. They are believed to be more common in women
than in men. They typically manifest in adulthood as
flesh-colored, small (2-4 mm) papules on the lower
eyelids or upper cheek regions. They are usually mul-
tiple and symmetric. Some have a slight yellow or tan
hue. Other areas of the body on which syringomas are
seen include the upper eyelids, neck, and chest. They
have been reported to occur on any region of the body.
Plaque-like syringomas have been reported to occur
on the forehead, and they have the appearance of a
flesh-colored to slightly yellow, broad, flat plaque with
minimal to no surface change. They can be quite large,
up to 4 to 5 cm in diameter. They are essentially asymp-
tomatic, but occasionally a patient complains of slight
intermittent itching or of an increase in size with stren- Syringoma. The most common location for syringomas is on the lower eyelid.
uous physical activity. This is possibly explained by the
eccrine nature of the tumors: Under conditions of activ-
ity, an increase in sweating causes the tumors to tran-
siently appear to enlarge. There are specific variants
seen in patients with diabetes mellitus and in those with
Down syndrome. A form of eruptive syringoma has
been described that typically afflicts the anterior trunk
and the penile shaft. Linear syringomas have been
reported to occur on a unilateral limb, and these have
been termed unilateral linear nevoidal syringomas.
The clinical differential diagnosis of eccrine syringo-
mas is relatively limited when the clinician encounters
symmetric small papules on the lower eyelids. The dif-
ferential diagnosis for a solitary syringoma is broad and
includes other adnexal tumors as well as basal cell car-
cinoma. The most difficulty arises when reviewing the
histological features of a syringoma that has been biop-
sied in a superficial manner. If the pathologist is not
given a thick enough specimen, the eccrine syringoma
can mimic a microcystic adnexal carcinoma. These two
tumors, one benign and the other malignant, can have
very similar histological features in the superficial
dermis. In some cases, it is only with a full-thickness Low power. The overlying epidermis is normal. High power. Clusters of cells with a pale cytoplasm
biopsy that a pathologist can confidently differentiate The tumor is located in the superficial dermis are found throughout the tumor. There is a back-
the two tumors. and is made up of comma-shaped dilated ductal ground of sclerotic stromal tissue. The comma-
Histology: The overlying epidermis is normal. The eccrine glands. shaped dilated ductal eccrine gland apparatus is
tumor is based within the dermis and is sharply circum- apparent.
scribed. The syringoma typically does not penetrate
deeper than the upper third of the dermis. Clusters of
cells with a pale cytoplasm are found throughout the
tumor. A background of sclerotic stromal tissue is Pathogenesis: Eccrine syringomas are believed to be Treatment: No treatment is necessary. If one wishes
always appreciated. A characteristic finding is the an overgrowth of the eccrine sweat ductal apparatus. to pursue therapy, it should be done with caution,
“tadpole” sign. The tadpole- or comma-shaped, dilated Researchers have proposed that this proliferation is because treatment experiences are anecdotal, and scar-
ductal eccrine gland apparatus is pathognomonic for caused by an inflammatory response to an as yet unde- ring may have a worse appearance than the syringoma
eccrine syringoma. Clear cell variants are associated termined antigen. The precise pathogenesis of eccrine itself. Electrocautery, light cryotherapy, chemical peels,
with diabetes mellitus. A microcystic adnexal carcinoma syringomas is unclear. Familial patterns suggest a laser resurfacing, dermabrasion, and excision have been
is poorly circumscribed, is asymmetric, and infiltrates genetic predisposition, but most patients do not have reported with variable results.
into the underlying subcutis. a family history to support genetic transmission.

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 19