AJR 2005; 184:205-206
© American Roentgen Ray Society
Radiologic-Pathologic Conferences of the Wilford Hall Medical Center |
Lymphangioma of the Foot
Justin Q. Ly1,
Bruce C. Gilbert2,
Steven W. Davis3,
Douglas P. Beall4 and
Randy R. Richardson1
1 Department of Radiology and Nuclear Medicine, Wilford Hall Medical Center,
2200 Bergquist Dr., Ste. 1, Lackland Air Force Base, TX 78236-5300.
2 Department of Medical Education, Brooke Army Medical Center, San Antonio, TX
78234.
3 Department of Pathology, Wilford Hall Medical Center, Lackland Air Force Base,
TX 78236–5300.
4 Department of Radiology and Nuclear Medicine, Oklahoma University Medical
Center, Oklahoma City, OK 73104.
Received October 10, 2003;
accepted after revision July 14, 2004.
The opinions and assertions contained herein are the private views of the
authors and should not be construed as official or as representing the views
of the Department of the Air Force, the Department of the Army, or the
Department of Defense.
Address correspondence to J. Q. Ly.
A 2-year-old girl who was known to have Turner's syndrome presented to her
primary care provider with an enlarging mass involving her left foot. Physical
examination revealed that the left foot was diffusely enlarged but not
discolored. Conventional radiography (Fig.
1A) showed a large infiltrating soft-tissue mass involving the
entire plantar aspect of the foot, without identification of phleboliths or
osseous abnormalities. Doppler sonography of the mass revealed no remarkable
blood flow. MRI (Figs. 1B and
1C) revealed a predominantly
nonenhancing soft-tissue mass containing variably sized cystic spaces showing
low to intermediate T1 signal and high T2 signal. Interspersed fat was noted
within the mass. No flow voids were identified. These findings indicated a
vascular lymphatic malformation. The patient underwent surgical amputation of
the left foot. The final histopathologic diagnosis was cystic lymphangioma
(Fig. 1D).
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Fig. 1A. —2-year-old girl with soft-tissue lymphangioma in left foot.
Conventional oblique radiograph shows diffuse massive enlargement of affected
foot, particularly at plantar aspect. Subcutaneous radiolucencies
(arrowheads) are oriented linearly and run parallel to long axis of
foot.
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Fig. 1C. —2-year-old girl with soft-tissue lymphangioma in left foot.
Axial T1-weighted fat-suppressed MR image obtained after IV contrast
administration shows corresponding nonenhancing hypointense cystic spaces
(arrowheads) and mild, diffuse subdermal enhancement of plantar
aspect that may represent hyperemic tissue.
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Fig. 1D. —2-year-old girl with soft-tissue lymphangioma in left foot.
Photomicrograph of surgical specimen shows ectatic lymphatics that have thin
walls composed of simple endothelial lining and are seen in papillary dermis.
Because these channels are close to undersurface of epidermis, some appear to
be in epidermis itself. (H and E, x40)
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Soft-tissue lymphangiomas are relatively rare tumors that may involve
almost any organ system. Approximately 90% of lymphangiomas are diagnosed in
children younger than 2 years and lymphangiomas account for only 6% of benign
childhood tumors. Although the specific origin is unclear
[1], most experts consider
lymphangiomas to be true congenital neoplasms resulting from erroneous
embryogenesis [2]. Soft-tissue
lymphangiomas most commonly occur in cervicofacial (up to 75%), axillary (up
to 25%), or mediastinal (3–10%) areas. Patients usually present with a
soft, fluctuant mass that has been progressively increasing in size. Rapid
enlargement of the lesion may be seen when there is associated bleeding or
infection. Histologically, lymphangiomas consist of ectatic lymphatic
channels, occasionally containing a mild lymphocytic infiltrate.
Classification by histologic appearance includes three subtypes: capillary,
cavernous, and cystic [3]. The
capillary form is composed of small thin-walled lymphatic vessels. Cavernous
lymphangioma consists of large lymphatic channels with adventitial coats. The
third and most common type, cystic lymphangioma or cystic hygroma, is composed
of macroscopic lymphatic spaces. These lesions are often multiseptated, which
is suggestive of infiltration across tissue planes. The different
classifications of this lesion may represent various stages of disease
[1]. In clinical practice,
vascular malformations are classified as high-flow or low-flow lesions. Those
containing arterial components are considered high-flow lesions. Capillary,
venous, and lymphatic malformations and their combinations are considered to
be low-flow lesions.
Radiography typically shows nonspecific findings. Sonography generally
shows excellent through transmission because of the cystic nature of this
process. Other sonographic findings may include multiple septations of varying
thickness and fluid–fluid levels that represent layering of the
hemorrhagic components of the lesion
[4]. Sonography may help in
differentiating a lymphangioma from a hemangioma, as there generally is no
significant Doppler flow in a lymphangioma. CT findings are often nonspecific
but can demonstrate the cystic nature of lymphangiomas. MRI is superior to
other techniques for defining soft tissues and is useful for further
characterization of the composition and extent of soft-tissue lymphangiomas.
Lymphangiomas characteristically appear as heterogeneous, fluid-filled masses
with low signal intensity (isointense to muscle) on T1-weighted images and
show high signal intensity (greater than fat) on T2-weighted images. These
fluid-containing spaces correspond to the histologic findings of ectatic
lymphatic channels. Additional findings may include fibrous septations seen as
linear hypointensities on T2-weighted images, fluid–fluid levels
representing hemorrhage, and aneurysmal dilatation of adjacent venous
structures [5]. Neither cystic
enhancement nor mild septal enhancement is seen in true lymphatic
malformations. However, enhancement may be seen in mixed
lymphatic–venous lesions.
The differential diagnosis includes hemangioma and venous malformation. On
MRI, lymphangiomas are characterized by the absence of feeding vessels and
lack of intense contrast enhancement. Venous and lymphatic malformations may
be difficult to differentiate on unenhanced MRI. After IV contrast
administration, the lack of significant intralesional contrast enhancement is
consistent with a lymphangioma. The lymphangioma in our patient's foot showed
characteristic MRI findings, allowing us to make an accurate preoperative
diagnosis.
Six percent of lymphangiomas spontaneously regress. The most widely
accepted treatment of this lesion is surgical excision. When complete
resection is accomplished, the rate of recurrence is low. However, because of
the infiltrating nature of the lesion, complete excision is reported in only
18–50% of cases [2]. One
third of children with incomplete resections have significant rates of
recurrence of the lesion. In those patients with contraindications to surgery,
nonsurgical treatment with diathermy, radiation therapy, or intralesional
injection of sclerosing agents are alternatives to be considered.
References
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lymphangiomas with OK-432 (Picibanil). Cardiovasc Intervent
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- Van Cauwelaert P, Gruwez JA. Experience with lymphangioma.
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- Lev S, Lev MH. Imaging of cystic lesions. Radiol Clin
North Am 2000;38:1013
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- Siegel MJ. Magnetic resonance imaging of musculoskeletal soft
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