3.1 | Case 1: KHE with KMP
Patient 1 presented at 3 months of age with petechiae and purpura on his
extremities. He had been diagnosed with an upper respiratory infection
and placed on a 10-day course of antibiotics within the previous 2 weeks
from presentation. Upon presentation to the emergency department his
platelet count was 2,000/mm3. Given his presentation
and recent viral illness, he was initially diagnosed with idiopathic
thrombocytopenia (ITP) and was given intravenous immunoglobulin (IVIG)
1g/kg. The following day his platelets remained at
11,000/mm3 and hemoglobin declined to 8.7 g/dL.
[Figure 1]
Ultrasound of the abdomen was performed as there was concern for
splenomegaly and due to the atypical ITP presentation at this age. A
retroperitoneal mass was discovered that appeared to be coming from the
tail of the pancreas. Computed tomography (CT) was performed for better
visualization and confirmed a 6.2 cm x 3 cm mass with heterogeneous
attenuation encompassing the splenic artery and extending into celiac
axis. Patient went to the operative room for biopsy of the lesion. Prior
to the procedure he was transfused platelets and platelet count
increased to 55,000/mm3. He had no bleeding
complications with the procedure. Coagulation panel was obtained on
hospital day 2 and revealed fibrinogen of 163 mg/dL and elevated d-dimer
of 22. This was repeated on hospital day 6 and fibrinogen was 299 mg/dL
and d-dimer 21.7.
Pathology was consistent with KHE. Given the thrombocytopenia and
elevated D-dimer he was diagnosed with KMP and prednisone 2mg/kg/day was
initiated. Consent was obtained from the family and he was started on
weekly intravenous vincristine 0.05mg/kg. His fibrinogen initially
dropped to 90 mg/dL and he was given cryoprecipitate, but his platelets
began to improve after only a couple of days of corticosteroids. Over
the subsequent 4 weeks his fibrinogen fluctuated from 86 mg/dL to 178
mg/dL and his platelets from 37,000/mm3 to
206,000/mm3. Steroids were very slowly weaned and were discontinued once
fibrinogen and platelets had consistently normalized. The lesion was
imaged with magnetic resonance imaging (MRI) every 3 months and saw
initial shrinkage but then remained stable. He was treated with 3
12-week cycles of vincristine and at the end of therapy, his blood
counts were normal and the KHE lesion was stable at 1.4 cm x 4 cm. He is
now 5 ½ years off therapy and doing well with no recurrent of the KMP
and no evidence of progression of the tumor.