Via Research Recognition Day 2024 VCOM-Carolinas

Clinical Case-Based Reports

Congenital Tufted Angioma With Mild Kasabach-Merritt Phenomenon: A Case Report Grace Ralston, OMS-II, Sarah Fabry, D.O. Edward Via College of Osteopathic Medicine – Carolinas Campus, Spartanburg, SC

Treatment

Introduction

Discussion

Sirolimus is a mammalian target of rapamycin (mTOR) inhibitor that blocks the IL-2 receptor signaling pathway. [6] Blocking this pathway will inhibit angiogenesis thus slow the growth of the vascular tumor and improve coagulopathy by reducing hypervascularization. [6] The behavior of a CTA can be challenging to predict despite its benign nature due to various documented clinical courses. [7,8] There are some studies that suggest those who develop CTA within the first year of life have a better prognosis and suggest utilizing the “wait -and- see” approach. [7] However, those who present with KMP require a more aggressive approach due to the increased morbidity and mortality risk. [8] If this patient had presented with the CTA without KMP, it would be a reasonable argument to abide by the “wait -and- see” approach since many cases of CTAs resolve spontaneously. [1,7] Due to the rapidly progressive nature of this patient’s clinical presentation, the benefits of aggressive treatment outweighed the costs. Notably, confirmatory diagnosis of a CTA is histological, whereas KMP is confirmed with labs. [3,4] The patient never received a biopsy, even once coagulopathy had resolved due to lack of parental consent. If the vascularity or coagulopathy recur, biopsy and further workup are indicated. Suspicion for vascular anomaly and laboratory evaluation early on were critical in this case to detect the KMP, allowing prompt, aggressive intervention with sirolimus. This case of a congenital tufted angioma with mild Kasabach-Merritt Phenomenon contributes to the literature as one of the many variable courses this disease process can take on to facilitate earlier diagnosis. Conclusion

A congenital tufted angioma (CTA) is a benign vascular neoplasm that presents before the age of 5 years old, with majority of cases presenting within the first 12 months of life. [1] CTAs present as solitary, violaceous, erythematous plaques with a mottled appearance that tend to occur on the trunk or extremities, but in some cases can involve the retroperitoneum. [1,2] Laboratory evaluation is crucial when evaluating a patient with a CTA due to risk for Kasabach-Merritt phenomenon (KMP). [3] KMP is characterized by a rapidly enlarging vascular tumor in addition to consumptive coagulopathy with hypofibrinogenemia, elevated D-dimer, and thrombocytopenia in some cases. [3,4] Prothrombin time (PT) and partial thromboplastin time (PTT) are typically normal to slightly elevated in majority of KMP cases, however, there is still increased risk for bleeding. [5] A 6-month-old male presented to primary care with an erythematous, irregularly shaped lesion extending across the entire lower abdomen, suprapubic, and inguinal regions that presented abruptly. Mild blanching was noted, but no tenderness to palpation. The patient appeared to be in no distress. The lesion was treated as “diaper rash” with numerous topical steroids, all resulting in failed clinical improvement. Erythema continued to progress, and the patient was referred to dermatology and eventually pediatric hematology/oncology. Labs demonstrated a significantly elevated D-Dimer and decreased fibrinogen levels. Platelets, PT, and PTT were normal. Ultrasound was unremarkable. Pelvic MRI demonstrated involvement of right abdominal wall musculature, but no masses or retroperitoneal involvement was noted. The patient exhibited no other symptoms and was otherwise clinically stable. Tumor board discussed the patient’s case and agreed that given the progressive nature of the vascular anomaly with consumptive coagulopathy, the patient was presenting with a congenital tufted angioma with mild Kasabach-Merritt phenomenon. A biopsy was recommended but postponed due to concern for increased bleeding risk. Despite the lack of histologic confirmation, sirolimus 0.8 mg/m 2 was initiated. Case Description

• Fibrinogen levels normalized by the 3rd month of treatment with sirolimus and remained stable, whereas D-Dimer levels did not normalize until the 13 th month of therapy (Figure 1). Recommended biopsy at 7-month follow up, but unable to obtain parental consent.

b.

a.

• Began weaning off sirolimus after 8 months and discontinued after 18 months of therapy • The appearance of the CTA continued to improve with significant reduction in erythema by the 14 th month of therapy. The size of the lesion remained unchanged (Image 1). Figure 1. a) Fibrinogen levels ; not checked the last 6 months of therapy since levels were within normal limits for most of the treatment. Shaded region represents reference range (215-494 mg/dL). b) D-Dimer levels ; not checked at 18-month follow up since therapy was discontinued at that visit. Shaded region represents reference range (<0.50 ug/mL FEU).

b.

a.

Image 1 . a) CTA prior to sirolimus therapy. b) CTA after 18 months of sirolimus therapy.

• Patient returned to clinic 6 months later with worsening erythema and recurring coagulopathy. A biopsy was recommended, but not performed due to parental concern regarding anesthesia and bleeding risks. • Re-started sirolimus therapy at a subclinical dose of 0.73 mg/m 2 . The patient did not reach goal trough levels most of this treatment course due to medication noncompliance. • Coagulopathy resolved after 10 months of treatment (most recent follow up). Started to wean off sirolimus at this visit. If coagulopathy recurs or CTA worsens, biopsy for histologic confirmation is necessary.

References

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