PB1774 ACUTE PROMYELOCYTIC LEUKEMIA PRESENTING AS VERTEBROBASILAR ISCHEMIC STROKE IN A YOUNG WOMAN
Authors: Brioso Infante J. , Martins H. , Alves D. , Valle S. , Lacerda J. , Esteves G. , Raposo J. 
Published: June 2019

Background:

Acute Promyelocytic Leukemia (APL) carries a high risk of early death due to coagulopathy triggered by the leukemic cells, which initiate a cascade of disseminated intravascular coagulation and hyperfibrinolysis. Patients are at risk for hemorrhagic and thrombotic events, but bleeding dominates the clinical picture and is responsible for most of the early deaths.

Arterial thrombosis is rare in APL, and its mortality is extremely high. The best management strategy when occurring in APL is unknown, since anticoagulants or fibrinolytics may aggravate the CID but without them the thrombosis may be fatal.

Aims:

We present a rare case of APL presenting as a vertebrobasilar ischemic stroke, which evolved favorably with treatment of the subjacent leukemia alone, without use of anticoagulation or antiaggregation.

Methods:

Case report.

Results:

A 36‐year old previously healthy woman presented with sudden onset aphasia and right‐sided hemiparesis with central facial paralysis, vertical gaze palsy and loss of horizontal gaze to the left.

Blood work showed anemia (Hb 6.6 g/dL), a white blood cell (WBC) count of 7900x109/L of which 62% were atypical promyelocytes, and 19,000 x109/L platelets (Figure 1‐A). A concomitant disseminated intravascular coagulation was diagnosed based on thrombocytopenia, hypofibrinogenemia (100 mg/dL), prolonged prothrombin time (> seconds) and elevated D‐dimers (10,98 μg/mL). These findings raised the suspicion of Acute Promyelocytic Leukemia, an entity usually associated with bleeding but also rarely with thrombosis.

Emergent head CT and angio‐CT scan showed no lesions. Based on the neurological findings, a presumptive diagnosis of vertebrobasilar ischemic stroke was established, and thrombolysis with alteplase was indicated. However, the risks of aggravating the bleeding predisposition of the patient and precipitating hemorrhagic transformation of the stroke outweighed the benefits, and both alteplase and anticoagulants were withheld.

Instead, management focused on treating the leukemia. Oral all‐trans retinoic acid was immediately initiated, and idarrubicin was added after confirming major infiltration of the bone marrow with atypical promyelocytes. Surprisingly, the hallmark translocation t(15;17) was not detected by fluorescence in‐situ hybridization (FISH), but the fusion transcript PML‐RARα was identified by reverse transcription with polymerase chain reaction (RT‐PCR), thus confirming a diagnosis of cryptic APL.

A magnetic resonance of the head performed 24 hours later showed hyperintense lesions in the left thalamus, caudate and midbrain, and right parietal operculum (Figure 1).

The patient achieved hematologic complete remission after induction therapy and recovered to a mild right hemiplegia after intensive physical rehabilitation. She is currently in molecular complete remission and is undergoing maintenance treatment in the outpatient setting, medicated with dipyridamole as secondary stroke prevention.

Summary/Conclusion:

The management of thrombotic events in APL is a challenge, since the increased bleeding risk associated with anticoagulation must be weighed against the potential lethality of the thrombosis if it is left untreated. Central nervous system arterial thrombosis has a particularly poor prognosis.

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We present a case that illustrates the importance of early APL treatment with ATRA and supportive measures in reverting the coagulopathy of the disease.