Pedi Rhabdomyosarcoma Flashcards
Second to accidents, what is the most common cause
of death in children between 1 and 14 years of age?
Malignancy
What is the most common sarcoma of childhood?
Rhabdomyosarcoma. Up to 35% are found in the head and neck.
Which cell type gives rise to rhabdomyosarcoma,
and what major histologic variants are described?
Primitive skeletal muscle cells (small, round blue cell tumor
of childhood): embryonal, botryoid, alveolar, undifferenti-
ated. Some include anaplastic. Embryonal and alveolar are the most common types, and embryonal type carries the
best prognosis.
Where does pediatric head and neck rhabdomyosar-
coma most commonly occur?
Parameningeal (50%): Paranasal sinuses, nasopharynx, nasal
cavity, middle ear, mastoid, infratemporal fossa (5-year
survival: 49%; considered high risk)
Orbit (25%) (5-year survival: 84%)
Nonorbital, nonparameningeal (25%): Scalp, parotid, oral
cavity, pharynx, thyroid, parathyroid, neck (5-year survival:
70%)
What are the common initial symptoms associated
with head and neck pediatric rhabdomyosarcoma?
Symptoms are due to progressive mass effect, local
swelling, neurologic sequelae, or tissue necrosis. Bone
marrow involvement can manifest as hematologic
concerns.
What are the most important negative prognostic
factors associated with pediatric rhabdomyosarcoma?
Diagnosis during infancy or adolescence; metastatic disease
at diagnosis; alveolar histology; disease identified in a
parameningeal location (risk for intracranial spread), in the
extremities, or in the retroperitoneum or trunk; recurrence
or progression during therapy
What diagnostic techniques are required to evaluate
the primary tumor in rhabdomyosarcoma?
Biopsy: Open biopsy is done to ensure adequate tissue
unless the lesion is small and difficult to access, in which
case, needle biopsy may be acceptable.
Imaging: CT scan and magnetic resonance imaging (MRI) to
evaluate extent of disease
What diagnostic techniques are required to evaluate locoregional and/or distant metastases in rhabdo-
myosarcoma?
Laboratory work (complete blood count [CBC], electrolytes,
liver function, coagulation studies, renal function tests)
Technetium-99 bone scan
CT chest
Positron emission tomography (PET)/CT scan
Aspiration/biopsy of iliac bone marrow.
Distant metastases are more commonly found in the brain,
lung, bone, and bone marrow.
Which group is credited with increasing the survival
rate for patients with rhabdomyosarcoma from 30 to 70% since the 1970s?
The Intergroup Rhabdomyosarcoma Study Committee
(now the Soft Tissue Sarcoma Committee of the Children’s
Oncology Group)
What is the clinical grouping or surgical pathologic staging system commonly used for staging rhabdo-
myosarcoma?
Group I Localized disease, completely resected
A Confined to organ or muscle of origin
B Invasion outside organ/muscle of origin; regional nodes not involved
Group II Compromised or regional resection including
A Grossly resected tumors with microscopic residual tumor
B Regional disease, completely resected, in which nodes may
be involved and/or tumor extends into an adjacent organ
C Regional disease with involved nodes, grossly resected, but
with evidence of microscopic residual
Group III Incomplete resection or biopsy with gross residual disease
Group IV Distant metastases, present at onset
What is the tumor, node, and metastases (TNM)
staging system for rhabdomyosarcoma introduced
by the Intergroup Rhabdomyosarcoma Study IV?
T1 Confined to the anatomical site or origin T2 Extension beyond site of origin A: ≤ 5 cm in diameter B: > 5 cm in diameter N0 No clinically involved lymph nodes N1 Clinically involved lymph nodes NX Clinical status unknown M0 No distant metastasis M1 Distant metastasis MX Distant metastasis unknown
Describe the staging system for
rhabdomyosarcoma that combines the TNM
and clinicopathologic groups to provide both
prognostic and therapeutic recommendations.
Rhabdomyosarcoma prognostic stratification and standard
treatment assignment (Prognosis, Event-Free Survival):
Excellent (> 85%)
Very good (75 to 85%)
Good (50 to 70%)
Poor (< 30%)
This system allows for risk-directed therapy.
Describe the favorable and unfavorable locations
for head and neck rhabdomyosarcoma.
Favorable: Orbit and eyelid
Unfavorable: Parameningeal
True or False. In a patient with localized nonorbital,
nonparameningeal head and neck embryonal
rhabdomyosarcoma, if complete surgical excision
can be achieved, radiation therapy may be avoided.
True. However, chemotherapy is recommended for all
patients with rhabdomyosarcoma.
Is elective neck dissection for clinically negative necks recommended in patients with nonparamen-
ingeal rhabdomyosarcoma of the head and neck?
No
