Hold the Chemo! Leukostasis, a Presentation of Brown Recluse | Figure 1
JIMHICR
Hold the Chemo! Leukostasis, a Presentation of Brown Recluse Spider Bite
Image descriptions: Right arm on admission and day 4 of hospitalization.
Case description:
Brown recluse spiders, also known as Loxosceles reclusa, are endemic to the Southwest and Central Midwestern United States. A bite from this spider can cause a range of clinical manifestations, anywhere from a painless papular lesion to life-threatening reactions. We report a possible spider bite presenting as leukostasis initially suspected to be acute leukemia. A 22-year-old female patient presented to the emergency department with confusion and right upper arm pain, redness, and swelling after a suspected spider bite. Initial labs showed WBC count of 103.5x10e3/µL, hemoglobin of 3.3 g/dL, positive Direct Coombs’ test, creatinine of 1.8 mg/dL, transaminitis, and lactic acid of 20 mmol/L. Acute leukemia with leukostasis was suspected. She was started emergently on hydroxyurea in conjunction with prophylaxis for tumor lysis syndrome. However, peripheral smear showed left-shifted granulocytosis with lymphocytosis, monocytosis, and no blast cells or evidence of myelodysplasia. Bone marrow aspirate showed mildly hypercellular marrow with myeloid hyperplasia and no myelodysplasia. Flow cytometry analysis confirmed a left-shifted myeloid maturation pattern with 0.3% myeloblasts. BCR-ABL1 and JAK2 testing was negative. Hence, she had no evidence of leukemia but rather had leukostasis from a spider bite. Hydroxyurea was stopped and follow-up labs normalized. Sphingomyelinase D in the brown recluse spider venom is unique to Loxosceles and Sicarius and may be responsible for the unique clinical presentation of loxoscelism. The presentation of hyperleukocytosis complicated by shock with an unclear history poses a diagnostic challenge. In diagnostic uncertainty, consider delaying chemotherapy until a diagnosis can be confirmed to avoid potential harm.
Image Description: A 52-year-old man presented with a 20-minute history of chest pain radiating to the left shoulder and neck, associated with dyspnea and diaphoresis. He had a history of hypertension, long-term smoking, and a sedentary lifestyle. On physical examination, bibasilar crackles were noted on lung auscultation. An electrocardiogram (ECG) was performed in the primary care setting, and the patient was promptly referred to the emergency department.
A 4-year-old girl presents to the emergency department with multiple bruises on her limbs and recent weight loss of 4 lb. When asked, the patient’s mother reports that the child has been progressively fatigued and seems to be weak. The patient’s past medical history is significant for hemophagocytic lymphohistiocytosis, for which she was treated with etoposide, corticosteroids, cyclosporine, and intrathecal methotrexate. She then received a bone marrow transplantation. Her current complete blood cell count shows anemia, thrombocytopenia, and marked lymphocytosis with 88% blasts. The peripheral smear is shown in Figure 1. Which one of the following statements regarding the phenotypic characteristics of acute leukemia is true?
A. CD19 expression is almost never observed in AML.
B. Terminal deoxynucleotidyl transferase (TdT) can be positive in a subset of AMLs.
C. It is not uncommon to see the absence of CD19 on B-cell lymphoblastic leukemias.
D. If the lesional cells express CD13, they must be of the myeloid lineage.
E. CD117 is commonly seen in ALL.
35yo F Spider bite suspected from brown recluse x10 days ago. Patient initially refused to go to hospital thinking that it would "get better" and EMS was contacted by family when they saw severity of patient's foot. Vitals HR 86 NSR, 97% 2L O2, BP 65/sys., LOC is normal. Unable to gain IV access, suspected drug user. IO placed in right leg. EMS treatment was NSS and fentanyl for pain management.
35 yr old male presents to ER stating he thinks he might have been bitten by brown recluse spider. Pictures show bite site with blister on right inner thigh. Patient states he has 3 other bites on knee and upon examination, those 3 bites are small, red and without blistering. Patient only has pain at inner thigh bite site. Is this brown recluse or maybe just dermatitis from unknown insect bite? Opinions?