Rhabdomyosarcoma is the most common primary orbital malignant neoplasm
of childhood. However, it constitutes only 4% of all orbital lesions studied
by biopsy in children.1 As it is a highly
malignant tumor, prompt diagnosis and treatment are imperative. Current therapeutic
regimens of radiation and chemotherapy have provided 93% 3-year survival.2 We
herein report a rare variant of orbital rhabdomyosarcoma
that showed magnetic resonance (MR) imaging findings of central cavitation,
simulating an orbital lymphangioma.
An otherwise healthy 4-year-old girl was referred to us because of abrupt-onset
proptosis of her right eye (Figure 1).
The parents had noted mild painless swelling of the right upper eyelid during
the previous 3 weeks.
Ptosis, proptosis, and inferotemporal
displacement of the right eye in a 4-year-old girl.
The visual acuity was 20/20 in each eye. There was 6 mm of right proptosis.
Motility was restricted in all gazes, and the right eye was displaced inferiorly
and temporally. Subtle subcutaneous ecchymosis was present at the inferotemporal
orbital rim. There was a dilated clear lymphatic channel on the conjunctiva
An MR image showed a superonasal heterogeneous soft tissue mass with
no bone erosion. On T1-weighted gadolinium-enhanced images, the central area
of the mass was hypointense, suggestive of proteinaceous material. A peripheral
hyperintense rim indicated vascularized tissue. There was a thin septum dividing
the central "cystic" area, but fluid-fluid levels were not seen (Figure 2A). T2-weighted images disclosed
an irregular isointense rim and central area of extreme hyperintense signal
(Figure 2B). These findings were
suggestive of lymphangioma with proteinaceous fluid and hemorrhage.
A, Coronal magnetic resonance
image (T1-weighted with fat suppression and gadolinium enhancement) showing
a nonenhancing low-signal central area compatible with proteinaceous fluid
or blood. The rim shows moderate enhancement. Note the septation within the
central area. B, Coronal magnetic resonance image (T2-weighted) showing the
central cavity with bright signal, again suggestive of proteinaceous fluid
A diagnosis of lymphangioma was favored in light of the rapid development
of proptosis, dilated conjunctival lymphatics, subcutaneous ecchymosis, and
the presence of presumed cystic, rather than solid, structures on MR imaging.
Cautious observation was advised, but 10 days later, worsening of the proptosis
and eyelid swelling prompted a biopsy. Intraoperatively, a multicystic blue
mass was found and aspiration of 1 mL of internal serosanguineous fluid collapsed
the mass. Near-total excision of the remaining mass was performed. These findings
continued to suggest the diagnosis of hemorrhagic lymphangioma.
Histopathologic examination disclosed undifferentiated small round cells
with hyperchromatic nuclei (Figure 3),
high nuclear-to-cytoplasmic ratio, and brisk mitotic activity. Immunohistochemistry
demonstrated intense immunoreactivity for smooth muscle actin and desmin.
These findings confirmed the diagnosis of rhabdomyosarcoma.
Photomicrograph showing poorly
differentiated, malignant "small blue cell tumor" with occasional strap cells
consistent with embryonal rhabdomyosarcoma (hematoxylin-eosin, original magnification
Radiotherapy (4500 rad [45 Gy]) and chemotherapy with cyclophosphamide,
dactinomycin, and vincristine sulfate were instituted by means of the Intergroup
Rhabdomyosarcoma Study Committee protocol.2
The patient continued to demonstrate complete tumor regression at 20 months'
Orbital rhabdomyosarcoma typically occurs as a unilateral solid mass
in the superonasal part of the orbit. The average age at diagnosis is 8 years.
Proptosis and displacement of the globe usually develop during a period of
weeks.3 Lymphangioma also occurs in a similar
age group, about 4 to 10 years of age. Bleeding into lymphangioma can produce
sudden proptosis and ecchymosis. Frequently, conjunctival involvement is found.4
Rhabdomyosarcoma can usually be differentiated from lymphangioma by
MR imaging. Rhabdomyosarcoma characteristically shows a solid homogeneous
mass that is isointense to vitreous on T1-weighted images.3
Lymphangioma demonstrates a multicystic mass with lobulated margins, showing
hypointensity to vitreous on T1-weighted images and hyperintensity to vitreous
on T2-weighted images. The rim of lymphangioma can enhance minimally.4 Our case had MR imaging characteristics most consistent
Cavitation can occur within other ocular tumors secondary to hemorrhage,
necrosis, and mucoid degeneration.5 However,
cavitation within rhabdomyosarcoma is distinctly unusual. To our knowledge,
this finding has not been previously reported. In a review of 250 orbital
childhood tumors by Shields and associates,1
there were no rhabdomyosarcomas with cavitation.
Our case presented a diagnostic dilemma. Rhabdomyosarcoma and lymphangioma
occur in similar age groups and are seen with similar clinical findings. The
malignant nature of rhabdomyosarcoma vs the benign course of lymphangioma
underscores the importance of correct diagnosis. Although conservative management
of lymphangioma is generally advised, proper follow-up should be performed.6 If the suspected lymphangioma fails to demonstrate
resolution or shows progression, biopsy should be considered to rule out rhabdomyosarcoma.
This study was supported by the Paul Kayser International Award of Merit
in Retina Research, Houston, Tex (Dr J. Shields); the Eye Tumor Research Foundation,
Philadelphia, Pa (Dr C. Shields); Noel T. and Sara L. Simmons Endowment for
Ophthalmic Pathology, Wills Eye Hospital, Philadelphia (Dr Eagle); and the
Department of Ophthalmology, Chang Gung Memorial Hospital, Taipei, Taiwan
Fetkenhour DR, Shields CL, Chao AN, Shields JA, Guterman CB, Eagle RC. Orbital Cavitary Rhabdomyosarcoma Masquerading as Lymphangioma. Arch Ophthalmol. 2001;119(8):1208-1210. doi: