MedPix Medical Image Database COW - Case of the Week Case Contributor: Tyler J Evans Affiliation: Childrens Hospital of Dayton, OH

MedPix No: History Pt Demographics: Age = 10 y.o. Gender = girl The patient is a 10-year-old black girl who was reportedly previously healthy, except for very mild asthma. Approximately 1.5 months prior to hospitalization, she developed a sore throat, nonproductive cough, snoring, and hoarseness. She was given analgesics along with antitussive medications to take at home. Her symptoms worsened over the next several days with increased right face and neck swelling plus right ear pain. She was re-evaluated and was given amoxicillin and had a neck x-ray performed ( not available for review). She was sent to the ENT clinic after three more days of increasing symptoms. She was directly admitted from ENT clinic to the hospital for IV antibiotics and possible I&D with a provisional diagnosis of peritonsilar abscess. PMHx: Asthma - Mother states triggers are: smoking, URI PSHx: None FHx: non-contributory.Social Hx: Lives with mom, 2 brothers, no pets, mom and brother smoke inside, she is in 4th grade (As and Bs), no daycare, immunizations up to date. ROS: Gen: slightly more fatigue, no increased fussiness HEENT: right ear pain, watery eyes/red eyes Pulm: +cough, no wheeze/SOB Otherwise normal. Downloaded by (-1)

MedPix No: EXAM & LABS Gen: alert, playful, NAD HEENT: +RR, no scleral injection, right cheek slightly edematous, MMM, right TM erythematous and slightly bulging, good cone of light, no purulence, right tonsil pushed past midline, 3+, saliva pooling in oropharynx. Neck: right posterior jaw slightly edematous, supple, shotty cervical LAN Otherwise normal.

Alveolar Rhabdomyosarcoma Large mass seen in the right parapharyngeal space. It enhances heterogeneously post gadolinium administration. - Downloaded by (-1)

Alveolar Rhabdomyosarcoma Axial CT of the neck with IV contrast. Large (5 cm diameter) heterogeneous mass in the right parapharyngeal space. It is solid in appearance with small areas of enhancement suggesting vessels within it. - Downloaded by (-1)

Alveolar Rhabdomyosarcoma The large mass seen in the parapharyngeal space is isointense on T1-weighted sequences. - Downloaded by (-1)

FINDINGS CT Neck with contrast on day of admission There is a large (5 cm diameter) heterogeneous mass in the right parapharyngeal space. It is solid in appearance with small areas of enhancement suggesting vessels within it. No evidence of fat or ossification. The mass appears to have eroded portions of the right mandible and possibly invaded the skull base. There is moderate adenopathy in the anterior cervical chains bilaterally. MRI neck with and without GadoliniumThe large mass seen on CT is again identified, centered in the right parapharyngeal space. Relative to muscle, it is hyperintense on T2-weighted sequences and isointense on T1-weighted sequences. It enhances heterogeneously. There are no prominent flow-voids within the mass to suggest large arteries. There are no findings to suggest significant bleeding at the biopsy site. The mass measures approximately 7.3 cm transverse x 3.3 cm AP x 4.3 cm vertical. Involvement of the skull base and mandible is better demonstrated on CT. There is no intracranial extension through the skull base foramina. The mass displaces the carotid sheath posteriorly, but does not encase the vessels. There is sluggish flow in the right jugular vein, but no definite invasion or thrombosis. The airway is effaced and displaced toward the left. The mass displaces the right parotid gland laterally; it is difficult to tell if the gland is invaded or simply compressed. No separate mass is identified. There are bilateral cervical chain lymph nodes, but none appears markedly enlarged.

DIFFERENTIAL DIAGNOSIS What is your Differential Diagnosis? Metastatic Neuroblastoma - Rhabdomyosarcoma - Nasopharyngeal Carcinoma - Juvenile Nasopharyngeal Angiofibroma - Leukemia - Lymphoma - Langerhans Cell Histiocytosis -

Diagnosis: Rhabdomyosarcoma (alveolar type) Dx Confirmed by: Cytology and chromosomes from biopsy of parapharyngeal mass

DISCUSSION