Page 66 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 3-1 Integumentary System

ADNEXAL CARCINOMA

Adnexal carcinomas are a diverse group of malignant
skin tumors that are derived from the various compo-
nents of the skin appendageal structures. These tumors
are extremely rare and comprise well less than 1% of
all skin cancers diagnosed annually. They are difficult
to diagnosis clinically because they can all mimic the
more common types of skin cancer, particularly basal
cell carcinoma and squamous cell carcinoma. They can Eccrine porocarcinoma. Nondescript Spiradenocarcinoma, presenting as a plaque on the
be diagnosed with certainty only after histological red papule or nodule. Ulceration may ear. Adnexal tumors are rare, and a biopsy for histo-
examination. These tumors are believed to be derived occur. A biopsy is required to diagnose logical evaluation is required for diagnosis.
from hair follicle, sebaceous gland, apocrine gland, or this rare form of skin cancer.
eccrine gland epithelium. They are thought to arise
de novo and can also arise from a preexisting benign
precursor. An example is an eccrine porocarcinoma
developing within an eccrine poroma.
Clinical Findings: These tumors are very rare,
and one is unlikely to consider them in the differential
diagnosis when evaluating an individual with an undi-
agnosed skin growth. There are few clues to their
origin, which makes diagnosis of these cancerous
tumors almost impossible based on clinical findings
alone. Most manifest as a solitary papule, plaque, or
dermal nodule. Most are asymptomatic, but pruritus,
bleeding, and pain may be present.
The diagnosis of these tumors requires tissue sam-
pling. A punch or excisional biopsy is the best method
to biopsy these lesions, because it allows the pathologist
to get a large enough piece of tissue to evaluate. A Microcystic adnexal carcinoma. Small Sebaceous carcinoma. Yellowish patch often located
punch biopsy is especially important to help differenti- plaque on cheek. Slow-growing tumor that around the eye, in this case near the medial canthus.
ate microcystic adnexal carcinoma from a benign syrin- can become quite large by the time of diagnosis These tumors may be seen in association with the
goma. The latter is very superficial in nature, whereas Muir-Torre syndrome.
the microcystic adnexal carcinoma displays a deep infil- Cutaneous Adnexal Tumors
trative growth pattern that will not be appreciated with Apocrine gland derived Eccrine gland derived
a superficial shave biopsy.
Pathogenesis: The pathogenesis of these tumors is Adenocarcinoma of Moll’s glands Adenoid cystic carcinoma
poorly understood. In contrast to basal and squamous Apocrine carcinoma Aggressive digital papillary adenocarcinoma
Ceruminous adenocarcinoma
cell carcinomas, they are unlikely to be caused by ultra- Cribriform apocrine carcinoma Clear cell eccrine carcinoma
violet light exposure. The rarity of the tumors makes Extramammary Paget’s disease Hidradenocarcinoma
them difficult to study. There appears to be no genetic Eccrine ductal adenocarcinoma
inheritance to these malignant tumors, with the lone Eccrine porocarcinoma
exception of the sebaceous carcinoma. Sebaceous car- Hair follicle derived Malignant chondroid syringoma
cinoma can be seen in the Muir-Torre syndrome, which Malignant proliferating trichilemmal tumor Malignant cylindroma
is inherited in an autosomal dominant pattern. Pilomatrix carcinoma Malignant eccrine spiradenoma
Histology: Each tumor is unique histologically. The Trichilemmal carcinoma Microcystic adnexal carcinoma
tumors can be subdivided according to the type of epi- Trichoblastic carcinoma Mucinous adenocystic carcinoma
thelium from which they are derived: sebaceous, hair Mucoepidermoid carcinoma
follicle, eccrine, or apocrine. The pathologist is able to Polymorphous sweat gland carcinoma
differentiate these tumors based on certain criteria. The Sebaceous gland derived Signet-ring cell carcinoma of the eyelid
tumors show varying amounts of cellular atypia and an Syringoadenocarcinoma papilliferum
invasive growth pattern. They are usually poorly cir- Sebaceous carcinoma Syringoid eccrine carcinoma
cumscribed with varying amounts of mitotic figures,
necrosis, and abnormal-appearing cells. Various gland-
like structures can be seen in some tumors, which can
be helpful in making the diagnosis. Often, special
immunohistochemical stains are used to help differenti- in some of the more aggressive subtypes such as the recurrence rate of these tumors are unknown. After
ate the subtypes of these tumors. eccrine porocarcinoma. Sentinel node removal and diagnosis and removal of these tumors, the patient
Treatment: These tumors should all be surgically evaluation has not shown any survival benefit to date. should have long-term follow-up to evaluate for
excised with clear surgical margins. The Mohs surgical Mohs surgery may lead to a decrease in recurrence rate recurrence.
technique has been used successfully to treat these and is tissue sparing. Because of the rare nature of these Adnexal tumors that have metastasized are treated
tumors, as has a standard wide local excision. Sentinel tumors and the lack of prospective randomized studies, with chemotherapy with or without radiotherapy. The
node removal and evaluation is not routinely per- it is difficult to determine the best removal method. For prognosis is poor for patients who develop metastatic
formed, but some clinicians advocate its use, especially the same reasons, the ultimate prognosis and the adnexal carcinoma.

52 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS