Boy with lower limb swelling

Clinical History

A boy presented with diffuse swelling in the right leg and foot with a purplish-blue colour patch over the anterior-lateral aspect of the right lower thigh and leg (Fig. 1). The swelling and skin patch was present since birth. On examination there was extensive port wine staining with thrombophlebitis.

Imaging Findings

Skiagram of lower limb revealed leg length discrepancy with lengthening of right femur/tibia/fibula bones with gross soft tissue thickening (Fig. 2). Coned views of the right leg revealed a well-defined calcified shadow in the soft tissue posterior aspect of the leg consistent with a large phlebolith (Fig. 3). On venous Doppler study, deep venous system revealed absence of anterior tibial and posterior tibial veins with streak-like appearance of femoral and popliteal vein (Fig. 4a). Superficial venous system revealed varicose veins along the lateral aspect of the lower limb. In addition there was diffuse soft tissue hypertrophy with many cystic dilated channels along the muscles and cutaneous tissues, and probably dilated lymphatic system (Fig. 4b). MRI done on 1.5T machine using STIR, PD, T1, T2 and MEDIC sequences MRI revealed hypertrophy of soft tissue with multiple hyperintense cystic areas in subcutaneous planes along posterior aspect of inguinal region, gluteal region, thigh and leg. In addition there were multiple phleboliths suggestive of deformed veins (Fig. 5).

Discussion

Klippel-Trenaunay syndrome (KTS) is characterised by a triad of capillary malformations, soft-tissue and/or bone hypertrophy and varicose veins/venous malformations. KTS was reported by two French physicians Maurice Klippel and Paul Trenaunay way back in 1990 [1]. Weber [2] reported association of these findings with arteriovenous fistulas. KTS is a sporadic, mesodermal developmental rare disorder that usually affects a single lower limb.
Capillary malformation is a haemangioma with cutaneous blue-purplish port wine stain. The cutaneous lesions are usually confined to a part of a hypertrophied extremity [3]. Limb hypertrophy in KTS is due to bone overgrowth, muscular hypertrophy and thickened skin [4]. Anomalies of the venous system can involve both superficial and deep systems. Prominent superficial varicose veins are present in the majority of patients with KTS. Deep vein anomalies include hypoplasia, aplasia, duplication and valvular incompetence [5]. Abnormalities of the lymphatic system include a decreased number of lymph trunks and nodes are reported in 70% of patients with KTS.
Our case had all manifestation of disease with capillary malformation in form of patch port wine stains, gross hypertrophy of soft tissue with underlying bone elongation, deep venous abnormality in form of aplasia and hypoplasia of lower limb veins, abnormality of superficial venous system in form of varicosities and in addition cutaneous lymphatic vesicles.
Local complications are due to underlying vascular anomalies and include cellulitis, dermatitis and thrombophlebitis. Visceral involvement may result in rectal bleeding and haematuria [6, 7].

Imaging plays an important role in the diagnosis and ongoing evaluation of KTS. At radiography, leg-length discrepancy, bone and soft tissue hypertrophy can be assessed. Phleboliths in a very young patient are pathognomonic for venous malformations and are manifestations of prior haemorrhage or thrombus. Sonography and colour Doppler help in diagnosing abnormal superficial and deep venous system, varicosities and arteriovenous fistula. CT of the abdomen and pelvis provides a noninvasive means of assessing visceral vascular malformations. Magnetic resonance (MR) imaging because of its inherent advantages of multi-planner imaging, better soft tissue differentiation and delineation is the modality of choice. MR angiography can be used for analysing vascular malformations in KTS.

Differential Diagnosis List

Final Diagnosis

Klippel-Trenaunay syndrome

URL:	https://eurorad.org/case/15708
DOI:	10.1594/EURORAD/CASE.15708
ISSN:	1563-4086