Page 39 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 2-12 Benign Growths

FIBROUS PAPULE

Fibrous papules are one of the most common benign Angiofibromas. Also termed fibrous papules.
skin growths encountered. They are often overlooked Can be seen in isolation. Multiple angiofibromas
or ignored during routine skin examinations. The exact associated with tuberous sclerosis are termed
incidence is unknown, but they are believed to be adenoma sebaceum.
extraordinarily common. These skin growths are most
frequently found on the nose, but they can occur any-
where, especially on the face.
Clinical Findings: Fibrous papules are typically
small, 0.5 to 5 mm in diameter. They are slightly oval
and dome shaped with an overlying smooth surface.
Most commonly, they are flesh colored to slightly
hyperpigmented. Fibrous papules can also have a
hypopigmented appearance. These benign tumors are
almost entirely asymptomatic. On occasion, a patient
notices a slight itching sensation; less frequently, a
patient may describe spontaneous bleeding or bleeding
after minor trauma. These growths are most often soli-
tary in nature, but multiple fibrous papules have been
reported. Fibrous papules most commonly occur in
young adults, especially in the third to fifth decades of
life. The most common location is the face, with the
nose and chin the two areas most commonly involved. Adenoma sebaceum (multiple angio-
Fibrous papules are considered to be angiofibromas.
Multiple angiofibromas can be part of a constellation fibromas) over both cheeks and nasal
bridge. This is a sign of tuberous sclerosis.
known as the tuberous sclerosis syndrome. The dif-
ferential diagnosis in a teenager with multiple angio-
fibromas should always include tuberous sclerosis.
However, solitary fibrous papules are extraordinarily
common and should not cause one to look for an under-
lying syndrome such as tuberous sclerosis. Pearly penile
papules are small, dome-shaped, 1- to 2-mm papules
found along the corona of the glans. These pearly
penile papules are histologically indistinguishable
from fibrous papules and are also considered to be
angiofibromas.
The differential diagnosis of a fibrous papule can be
quite broad, and a biopsy is often required to differenti-
ate the potential mimickers. The entities most com-
monly included in the differential diagnosis are common
acquired melanocytic nevus and basal cell carcinoma. In
these cases, a shave biopsy is required to make a firm
diagnosis.
Histology: A fibrous papule is considered to be an
angiofibroma. There are multiple histological variants
of fibrous papules. The most commonly encountered
fibrous papules are typically dome shaped and small (up
to 5 mm in diameter), and they show a proliferation of
fibroblasts with a stroma of fibrotic collagenized mate- Low power. Well-circumscribed dermal tumor High power. Fibroblasts are the main cell type
rial. Dilated blood vessels are often found within the with multiple small blood vessels can be seen along with the blood vessels.
papules. An inflammatory infiltrate is frequently seen, within a fibrous stroma.
but it is typically sparse. The combination of clinical
findings with the typical histopathological findings
solidifies the diagnosis.
Multiple histological variants have been described, a collagen-filled stroma. Immunohistochemical staining of angiofibromas located symmetrically on the face
including pleomorphic, pigmented, granular cell, has shown that the dermal dendrocyte is the most likely and nose.
hypercellular, and clear cell variants. These variants are precursor cell to the abnormal fibroblasts seen in Treatment: No treatment is necessary, although a
believed to be much less common than the classic type fibrous papules. The underlying cause has yet to be small shave biopsy is often all that is required to
of fibrous papule. They have been described in detail determined. The multiple angiofibromas of tuberous remove the fibrous papule with an excellent cosmetic
and are well accepted and recognized histopathological sclerosis are directly related to an underlying defect in result. Most fibrous papules are removed because
variations. the tumor suppressor gene, tuburin (TSC2). Patients they are mistaken for basal cell carcinomas or for
Pathogenesis: Fibrous papules are believed to be a with tuberous sclerosis also have angiofibromas in a relief of some underlying irritation, such as itching or
benign proliferation of fibroblasts and blood vessels in periungual location, as well as hundreds to thousands bleeding.

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 25