Pedi Cutaneous Lesions

Question 1

You are evaluating a 14-year-old girl with a
well-defined tan (or yellow orange) verrucous/
papillomatous hairless plaque on her scalp. This
lesion has been present since birth, but it was not
particularly bothersome. However, as she has begun
to go through puberty, it has become significantly
more prominent. What is the likely diagnosis and
explanation for this change?

Answer 1

Nevus sebaceous. Puberty results in hyperplasia of the

sebaceous and apocrine glands within the lesion.

Question 2

What is the potential risk of simply observing

nevus sebaceous in children?

Answer 2

A (very low) risk of developing basal cell carcinoma. Other
benign tumors may also develop from these lesions
(syringocystadenoma papilliferum, trichoblastoma, nodular
hydradenoma, sebaceous carcinoma, etc.). All can be
removed by simple excision.

Question 3

What is the preferred management of nevus

sebaceous in children?

Answer 3

Observation and education are preferred over surgical
excision (which is indicated for cosmetic concerns as
excision may be easier in infancy or childhood or for the
development of a benign or malignant neoplasm).

Question 4

A worried mother brings her son for evaluation of
several ”dots” she has noted on his face that were
not present at birth. On evaluation, these “lesions” are
light brown, homogeneous, and round. They are flat
and appear rather symmetric. What is the likely
diagnosis?

Answer 4

Acquired melanocytic nevi (typical/acquired) (i.e., freckles)

Question 5

What is the most likely cause of a well-demarcated

lesion on an infant’s neck or chest?

Answer 5

Congenital melanocytic nevi: an error in proliferation and
migration of melanocytic progenitor cells (neuroectoderm)
during embryogenesis

Question 6

What are the size categories for congenital
melanocytic nevi, and how do these categories
relate to the potential for malignant conversion?

Answer 6

● Small: < 1.5 cm
● Medium: 1.5 to 2 cm
● Large: > 20 cm
● Giant: > 50 cm

Malignant potential (melanoma, neurocutaneous mela-
nocytosis, rhabdomyosarcoma) increases with increasing

size. An increasing number of satellite lesions also increases
the risk.

Question 7

How are congenital melanocytic nevi managed?

Answer 7

Treatment should be individualized based on cosmetic and
emotional impact, as well as the risk for malignancy.
Options range from surgical excision to dermabrasion and
chemical peels to simple observation.

Question 8

Name the pediatric skin lesion that is generally
smaller than 1 cm in diameter, dome shaped, and
well circumscribed; it can be purple, red, black or
brown; it is composed of spindled and/or large
epithelioid cells; and it can be quite difficult to
differentiate from melanoma.

Answer 8

Spitz nevus

Question 9

What are the three subtypes of Spitz nevi?

Answer 9

Conventional Spitz tumor (benign or low-grade melanocytic

neoplasm)
Atypical Spitz tumor (larger, irregular, more atypia,
increased risk for local lymph node involvement, and often
difficult to differentiate from melanoma)
Malignant Spitz tumor/melanoma (histologically difficult to
differentiate from melanoma, malignant lesion)

Question 10

How are Spitz tumors managed?

Answer 10

Conventional Spitz nevi should be excised with surgical margins of 3 to 5 mm.
Atypical Spitz nevi should be excised with wider margins
(up to 1 cm), with consideration for sentinel lymph node
biopsy and completion lymphadenectomy for positive
nodes. (Note: Up to 50% of sentinel lymph node biopsies
will be positive, with questionable impact on survival/
outcome.)
Malignant Spitz tumor/melanoma: Treat as malignant
melanoma

Question 11

Describe some common characteristics of a

dysplastic nevus.

Answer 11

A skin lesion with a macular (flat, nonpalpable) component,
irregularly distributed pigmentation, indistinct boundary

(“fried egg”), size > 5 mm, irregular border, and a back-
ground of erythema. This lesion is commonly seen on the

scalp but not in chronically sun exposed areas such as the
face.

Question 12

What is the clinical significance of dysplastic nevi

or a family history of melanoma?

Answer 12

It carries an increased risk for melanoma, although atypical

nevi generally do not represent a premalignant lesion.

Question 13

What is required to diagnose familial dysplastic

nevus syndrome?

Answer 13

> 100 melanocytic nevi, at least one clinically dysplastic

nevus, and at least one nevus > 8 mm

Question 14

When is biopsy indicated for a dysplastic nevus?

Answer 14

Biopsy is done when clinically and dermoscopically it is

difficult to differentiate the lesion from melanoma.

Question 15

What is required for the diagnosis of familial

atypical mole and malignant melanoma syndrome?

Answer 15

> 50 common and/or atypical nevi + a history of melanoma
in one or more first-degree relatives. (Autosomal dominant,
genetic association: CDKN2A gene mutations).

Question 16

What clinical criteria are required to diagnose
nevoid basal cell carcinoma syndrome (,i.e., Gorlin
syndrome, basal cell nevus syndrome)?

Answer 16

Two major or one major and one minor criteria:
Major criteria:
● More than two basal cell carcinomas (BCCs) or 1 basal cell
carcinoma in a patient < 20 years old
● Odontogenic keratocyst of the jaw (histologically proven)
● Three or more palmar or plantar pits
● Bilamellar calcification of the falx cerebri
● Bifid, fused, or markedly splayed ribs
● First-degree relative with the disease
Minor criteria:
● Macrocephaly
● Congenital malformations (i.e., cleft lip/palate, frontal
bossing, coarse facies, moderate/severe hypertelorism)
● Skeletal anomalies (i.e., Sprengel deformity, marked
pectus deformity, marked syndactyly)
● Radiographic anomalies (i.e., bridging of the sella turcica,
vertebral anomalies, modeling defects of the hands and
feet, or flame-shaped lucencies of the hands and feet)
● Ovarian fibroma or medulloblastoma

Question 17

What is the genetic defect associated with nevoid

basal cell carcinoma syndrome?

Answer 17

PTCH1 (patched) gene, chromosome 9q22.3, tumor sup-

pressor gene

Question 18

What treatment options are available for nevoid

basal cell carcinoma syndrome?

Answer 18

Surgical resection (wide local excision, Mohs surgery, laser

ablation), topical therapy (imiquimod, tretinoin, 5-fluoro-
uracil), photodynamic therapy, systemic therapy (oral retinoids, vismodegib). Radiation is largely avoided because
of the risk of developing basal cell carcinomas. Note:
Vismodegib has shown good efficacy in treating this
disease.

Question 19

You are examining a 5-year-old girl with a mobile,
rock-hard mass on her lateral cheek in the deep
dermis or subcutaneous layer of the skin. The
mass has been present for some time and has
shown slow growth. It has an irregular border and
is completely asymptomatic. What is the likely
diagnosis?

Answer 19

Pilomatricoma (mutations in the β-catenin gene arises from

the outer root sheath of hair follicles).

Question 20

Although most pilomatricomas are isolated lesions
located predominantly in the head and neck
(lateral cheek, preauricular area, and periorbital
area), when they occur as multiple lesions, what
additional diagnoses should be investigated?

Answer 20

Gardner syndrome, myotonic dystrophy, Rubenstein-Taybe

syndrome, Turner syndrome

Question 21

What is the recommended management for

pilomatricomas?

Answer 21

Surgical excision. They do not spontaneously regress.

Question 22

Infantile hemangiomas are the most common
benign neoplasm in childhood and are
differentiated from other vascular malformations
by the presence of what molecular marker?

Answer 22

Glucose transport protein 1 (GLUT-1)

Question 23

A 12-month-old infant is undergoing inpatient
medical treatment of a bright red, large, vascular
growth involving her right cheek and orbit. What
is the medication, and what side effects may occur
with this treatment?

Answer 23

Propranolol: hypoglycemia and rarely hypotension and

bradyarrythmias

Question 24

You are examining an infant with a
well-demarcated, dome-shaped, yellow-brown (or
reddish-orange) papule (or nodule) on the neck.
What is the likely diagnosis?

Answer 24

Juvenile xanthogranuloma: Benign, spontaneously regress-
ing lesion with an excellent prognosis, occasionally asso-
ciated with neurofibromatosis

Question 25

Juvenile xanthogranulomas of the head and neck
can be single or multiple, involve ocular structures
(more common with multiple lesions in children
under 2 years of age), regress within 2 years, and
can be confirmed on biopsy if the diagnosis is
suspect. What findings would you look for on
pathology to confirm the diagnosis?

Answer 25

Dense infiltrate of foamy histiocytes in the dermis and cells
containing a wreath of nuclei surrounded by eosinophilic
nuclei (Touton giant cells)

Question 26

What autosomal recessive genetic disorder results
in extreme sensitivity to sunlight (i.e., early
freckling, intense/prolonged burns), the potential
for neurologic sequelae (i.e., cognitive impairment,
ataxia, choreoathetosis, sensorineural hearing loss,
spasticity, seizures, and peripheral neuropathy), and a
greatly elevated incidence of cutaneous malignancies
(i.e., basal cell carcinoma, squamous cell carcinoma,
and melanoma)?

Answer 26

Xeroderma pigmentosum

Question 27

What is the genetic defect associated with

xeroderma pigmentosum?

Answer 27

A defect in the DNA repair mechanism; autosomal
recessive; eight genes have been identified (XPA–XPG,
excluding XPF)

Question 28

What management options improve the prognosis

for patients with xeroderma pigmentosum?

Answer 28

Aggressive sun protection and early detection and man-
agement of cutaneous malignancies improve prognosis.
Patients without neurologic involvement may have a good
prognosis with this strategy.

Question 29

Although pediatric head and neck melanoma is
quite rare, what is the prognosis compared with
adult populations?

Answer 29

Similar survival time but shorter disease-free intervals

Question 30

How is pediatric head and neck melanoma

managed?

Answer 30

Wide local excision, sentinel lymph node biopsy, neck
dissection for positive sentinel nodes, and consideration of
interferon α-2b in high-risk individuals