Stewart-Bluefarb Syndrome: A Rare Presentation of Acroangiodermatitis
Year: 2024
Type: article
Abstract: Dear Editor, Acroangiodermatitis is a rare angioproliferative condition, which occurs in two different settings. The commoner variant, acroangiodermatitis of Mali, presents in the background of chronic venous insufficiency as purpuric macules and papules that coalesce to form irregular plaques and involve bilateral lower limbs. In contrast, the other variant, Stewart–Bluefarb syndrome (SBS), presents in association with underlying arterio-venous malformation as dusky erythematous papules and plaques, unilaterally.[1,2] A 21-year-old female presented with asymptomatic reddish skin lesions over the left lower leg for 10 years. The lesions started as small dusky erythematous papules, which gradually increased to the current size over 10 years. On examination, there were dusky erythematous to coppery macules and papules coalescing to form larger plaques over the left lower leg. The plaques had irregular well-defined margins, varying in size from 2 cm × 2 cm to the largest measuring 10 cm × 7 cm [Figure 1a and b]. No limb length or girth discrepancy was observed. The rest of the mucocutaneous examination did not reveal any other abnormality. Polarized dermoscopy revealed a coppery background with white lines, focal multicolored structureless areas, and lacunae [Figure 2]. Doppler ultrasound study revealed varicosities involving the left great and short saphenous veins along with multiple perforator incompetence. Magnetic resonance (MR) angiography revealed multiple tortuous, dilated vascular channels along the subcutaneous plane of the medial aspect of the left leg, appearing T1 hypointense and T2/STIR (short tau inversion recovery) hyperintense, suggestive of slow-flow channels and superficial varicosities. No evidence of phleboliths was found. Multiple discrete flow voids were observed at the medial surface of the lower leg, approximately 10 cm cranial to the ankle joint. These voids were observed draining into the varicosities through a dilated (~8 mm) vascular channel connecting to the posterior tibial artery, suggesting a high-flow channel with venous communication. In 4D time-resolved MR angiography with keyhole (4D TRAK) imaging, there was a hypertrophied posterior tibial artery with multiple collaterals (compared to the opposite side) showing post-contrast enhancement and early draining veins. No evidence of intervening mass or soft tissue component was observed. The overlying skin and subcutaneous tissue exhibited heterogeneous T1 and T2 hypointensity with thickening, suggestive of fibrosis. The underlying bone appeared normal, and visualized bones, muscles, and tendons showed normal signal intensity. Both the knee joint and ankle joint appeared grossly normal, with no evidence of limb overgrowth. The presence of a hypertrophied posterior tibial artery and early draining veins connected by a dilated vascular channel along with multiple superficial varicosities in the absence of a definite nidus, soft tissue, or bone abnormality suggested the possibility of an arterio-venous fistula with superficial varicosities [Figure 3a and b]. Histopathological examination revealed mild hyperkeratosis, proliferating and dilated capillaries in the superficial and mid-dermis with erythrocyte extravasation and hemosiderin deposition [Figure 4a] which was confirmed on Perl’s stain [Figure 4b]. Immunostaining with HHV-8 was negative. Based on clinical, dermoscopic, and histological features, the patient was diagnosed as a case of SBS secondary to underlying arteriovenous (varicose veins and high flow arterio-venous fistula) malformation. However, genetic testing for MAP3K3 mutation, to rule out verrucous hemangioma which may closely resemble SBS, could not be performed due to limitations in resources within the setting. The patient was advised to use compression stockings and avoid prolonged standing. Angio-embolization was considered; however, it was not performed due to the high risk of cutaneous ischemia and necrosis/ulceration after consultation with an interventional radiologist. Surgical intervention was also considered high risk in this case, following consultation with a cardiothoracic vascular surgeon, due to the presence of superficial varicosities, which pose a higher risk of complications such as excessive bleeding and infection in such cases. Ultimately, the decision to defer surgery in this case of arterio-venous fistula with superficial varicosities was taken based on a careful assessment of the patient’s overall health, the risk–benefit ratio of surgery, and the patient’s preferences. Hence, a therapeutic trial of sirolimus 2.5 mg/day (0.04 mg/kg) was administered after obtaining written informed consent from the patient. However, sirolimus was stopped after 6 months due to non-response.Figure 1: Dusky erythematous plaques on (a) Dorsum; (b) Medial aspect of left lower legFigure 2: Polarized dermoscopy showing (a) Multi-coloured areas of blood-filled lacunae (yellow circles) and pseudo-reticular (green arrows) pigmentation (Dinolite, 30x); (b) Hemorrhagic crust (Dinolite, 30x)Figure 3: Magnetic resonance angiography showing (a) In 4D time-resolved MR angiography with keyhole (4D TRAK) imaging, a hypertrophied posterior tibial artery (red arrow) with multiple collaterals (compared to the opposite side) showing post-contrast enhancement and early draining veins, multiple tortuous, dilated vascular channels (green arrow) along the subcutaneous plane of the medial surface of the left leg, appearing T2/STIR (short tau inversion recovery) hyperintense suggestive of slow-flow channels and superficial varicosities. (b) Short tau inversion recovery (STIR) sagittal view showing heterogeneous T1 and T2 hypointensity with thickening (green rectangle) suggestive of fibrosis in the overlying skin and subcutaneous tissueFigure 4: Histopathology section showing (a) Dilated capillaries in superficial and mid dermis with RBC extravasation, capillary proliferation, and dermal fibrosis (H and E, 100x); (b) Hemosiderin deposition outside capillaries (Perl’s Prussian Blue; 100x)Arteriovenous malformations of the acral site lead to ischemia distal to the site of involvement due to the steal phenomenon. Shunting of blood via the malformation results in ischemia, causing the release of growth factors such as hypoxia-inducible factor 1α (HIF-1α), vascular endothelial growth factor (VEGF), and platelet-derived growth factor (PDGF) from the endothelial cells and the stroma. These factors induce neo-angiogenesis, resulting in the proliferation of endothelial cells and fibroblasts.[3,4] The severity of SBS is graded depending on the extent and severity of cutaneous and systemic involvement. The different stages are: Stage I-asymptomatic macules and plaques, Stage II-pulsatile expansile lesions, Stage III-destructive stage with complications such as skin ulceration and lytic changes in underlying bones, Stage IV-overt heart failure.[3] Our patient had stage I involvement. Only a few cases of SBS have been reported to date. Differential diagnoses of SBS are summarized in Table 1.[1,5] Dermoscopy may help in the visualization of subtle clinical features and in understanding the pathogenesis. The coppery background with multiple structureless areas, observed on polarized dermoscopy, reflects stasis dermatitis changes with RBC extravasation and hemosiderin deposition, whereas the white lines reflect fibrotic bands in the dermis. Multicolored focal structureless areas and lacunae represent blood-filled spaces due to capillary dilatation, whereas capillary proliferation imparts a rainbow color on dermoscopy. The polychromatic appearance was initially described in Kaposi sarcoma, but has subsequently been reported in other vascular pathologies as well as non-vascular lesions such as melanoma, dermatofibroma, and keloids.[5] The need for genetic testing is vital in distinguishing between SBS and verrucous hemangioma due to their close similarity. The presence of a MAP3K3 mutation in verrucous hemangioma highlights the importance of mutation analysis in guiding treatment choices, with mutation-based therapies such as trametinib showing promise. Therefore, comprehensive genetic analysis is crucial to accurately differentiate between these conditions and customize treatment plans accordingly. Its treatment is complex and requires targeting the arterio-venous malformation.[6-8] It is generally agreed that the treatment of SBS should be conservative. These modalities include compression stockings and limb elevation, which are beneficial in reducing edema. If secondary ulceration occurs, it should be managed like other vascular ulcers. Arterio-venous malformations are usually amenable to embolization; however, there is risk of cutaneous ischemia (in case of superficial lesions), which may manifest in the form of discoloration or ulceration.[6,8] Refractory pain, infection, bleeding, or progression to cardiac failure warrant aggressive management and may warrant amputation in the most severe cases.[6,8] Regular follow-up is advised to detect such complications at an early stage.Table 1: Differential diagnosis of Stewart-Bluefarb syndromeDeclaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.
Institution: All India Institute of Medical Sciences
Language: English
Subfield: Surgery
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W4402515648