記住我
Click on image for details.
NEUROIMAGE
Year : 2023 | Volume
: 71
| Issue : 5 | Page : 1106-1107
”Empty Tunnel Sign” in Essential Thrombocythemia
Megha Birajdar1, Pooja Dugani2, Divya Nagabushana2, JV Mahendra2, Purushottam T Acharya2
1 Department of General Medicine, Ramaiah Medical College, Bengaluru, Karnataka, India
2 Department of Neurology, Ramaiah Medical College, Bengaluru, Karnataka, India
Correspondence Address:
Divya Nagabushana
Department of Neurology, Institute of Neurosciences, Ramaiah Medical College, Bengaluru, Karnataka - 560 054
India
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/0028-3886.388047
How to cite this article:A previously well 21-year-old male presented with holocranial headache of 1 month duration with associated vomiting and blurring of vision. Examination revealed bilateral papilledema with no focal deficits. Contrast-enhanced magnetic resonance imaging (MRI) brain showed a long segment filling defect in the venous sinuses involving the posterior one-third of the superior sagittal sinus, right transverse sinus, sigmoid sinus, and proximal internal jugular vein, suggestive of thrombosis [Figure 1]. Hemogram revealed isolated thrombocytosis (7.83 lakhs/mm3). Procoagulant workup done showed mildly elevated serum homocysteine levels (19.23 μmol/L). Antiphospholipid antibodies, flow cytometry for detection of paroxysmal nocturnal hemoglobinuria, and antinuclear antibodies were negative. Reactive causes of thrombocytosis were ruled out. Bone marrow studies showed hypercellular marrow with marked megakaryocytic hyperplasia and normal erythroid, myeloid, and lymphoid series. Molecular testing for JAK2, MPL, CALR, and BCR–ABL mutations for the evaluation of myeloproliferative neoplasms and essential thrombocythemia (ET) was negative. As per literature, 13% of patients with ET are triple-mutation negative (JAK2, MPL, CALR). Around 1% of the cases with ET can present with venous thrombosis as the initial clinical manifestation.[1] Our patient received low-molecular-weight heparin followed by acenocoumarol along with antiedema measures. He showed complete resolution of the symptoms in 1 month. He was also started on cytoreductive therapy, namely, hydroxyurea. His platelet count reduced to below 4.5 lakhs after 4 months of treatment. The repeat computed tomography (CT) venogram after 1 year of treatment showed complete resolution of thrombosis [Figure 2]. The unique feature of this case is the distinct radiological appearance of the extensive, long segment, contiguous thrombus causing a filling defect, which has an appearance of a long, empty, and dark tunnel. Hence, we choose to call it the “empty tunnel sign” in ET. Extensive cerebral venous sinus thrombosis has been described in other cases of ET,[2],[3] and presence of this radiological sign may be considered an indicator to evaluate for essential thrombocythemia.
Figure 1: (a) T1 contrast sagittal MRI image demonstrating thrombosis of the posterior one-third of the superior sagittal sinus. (b–h) T1 contrast coronal MRI sequences showing long segment filling defect and distension in the right transverse sinus, sigmoid sinus, and proximal right internal jugular vein, suggestive of thrombosis. MRI = magnetic resonance imaging (Arrow indicates the extensive thrombus)
Figure 2: CT venogram at follow-up showing complete resolution of thrombus. CT = computed tomographyDeclaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patient understands that his names and initials will not be published and due efforts will be made to conceal his identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
留言 (0)