A Novel Mechanism of the “Three Territory Sign” in Acute Ischemic Stroke
Michael Figueroa1, Felipe Kazmirczak2, Solmaz Ramezani Hashtjin3, Christopher Streib1
1Neurology, 2Cardiology, University of Minnesota, 3University of Minnesota
Objective:
To present an atypical mechanism for multi-territorial infarction, the “Three Territory Sign” (TTS), in patients with Acute Ischemic Stroke and malignancy.
Background:
Multi-focal ischemic infarcts are often associated with cardioembolism.  However, bilateral anterior circulation and  posterior circulation infarcts are known as the TTS which is most commonly associated with hypercoagulable state due to malignancy  Two commonly recognized  mechanisms for the TTS in this setting are localized DIC and embolization of vegetations from non-bacterial thrombotic endocarditis.  We present a third possible mechanism for the TTS.

Design/Methods:
NA
Results:
A 67-year-old woman with history of Stage IV metastatic melanoma presented to the emergency department with one-day history of fine motor dysmetria and weakness of the right hand.  Brain MRI revealed extensive scattered infarcts throughout the bilateral anterior and posterior circulation.  A routine stroke work-up including vessel imaging, lipid panel, A1C, TTE and TEE were unrevealing.  Due to persistent eosinophilia, she then underwent cardiac MRI to assess for  possible chemotherapy-induced eosinophilic myocarditis.  While this was not present, her cardiac MRI  revealed a left-ventricular intramural metastasis with necrotic core directly invading the ventricular surface.  No other cardiac sources were discovered and the most likely source of this patient’s embolic strokes was felt to be thrombosis superimposed upon the necrotic intraventricular tumor.

Conclusions:
Intraventricular cardiac metastasis is an uncommon mechanism of malignancy-associated TTS.  Physicians should consider evaluation for cardiac metastases in patients with TTS if it will change optimal secondary stroke prevention or cancer treatment.
10.1212/WNL.0000000000204004