De novo Familial Cavernous Malformation Presenting with Hemorrhage 12.5 Years after the Initial Hemorrhagic Ictus: Natural History of an Infantile Form
The risk of hemorrhage from an intracerebral cavernous malformation has been estimated at 2%–4% per year. In patients with multiple cavernous malformations, typically there are 1 or 2 dominant lesions that result in symptoms. This report highlights an unusual case of recurrent hemorrhage from de novo cavernous malformations.
This 35-year-old man had a generalized seizure in 2007. Magnetic resonance imaging performed at the time showed multiple hemorrhagic lesions suggestive of cavernous malformations. Two years later, the patient had clinical symptoms referable to a midbrain hemorrhage. This lesion was not present on 2007 standard and gradient echo images. One year later, the patient had another clinical hemorrhage at the cervical medullary junction. This lesion was also not present on earlier imaging. Genetic testing was negative for the known familial types of cavernous malformation. A lesion was biopsied to ensure correct diagnosis, and the results were pathologically consistent with a cavernous malformation. The patient had a fourth clinical hemorrhage in 2011 from a separate lesion. All hemorrhage symptoms were mild, and he returned to normal functioning and work after each hemorrhage.
This case highlights several unusual features of the known natural history of intracerebral cavernous malformations. In this case, resection of the hemorrhagic lesion would not have altered future hemorrhage risk since each new hemorrhage was from a de novo lesion.
DNMT3A Overgrowth Syndrome (DOS, also known as Tatton-Brown Rahman Syndrome/TBRS) is one of several overgrowth syndromes with complex phenotypes caused by constitutional mutations in genes encoding epigenetic regulators. The clinical features of DOS are variable but include overgrowth (tall stature and/or obesity) and intellectual disability. DNMT3A is essential for de novo DNA methylation and plays an important role in hematopoiesis. Somatic mutations in DNMT3A are among the most common initiating mutations in normal karyotype acute myeloid leukemia (AML) patients and in elderly people with clonal hematopoiesis. The natural history of DOS has not been fully explored since the first description of this rare condition in 2014. Because of the association of somatic DNMT3A mutations and leukemia development, we assessed information from the ~200 known DOS patients world-wide and were able to document eight with hematologic malignancies. Based on this prevalence, we suggest DOS is a cancer predisposition syndrome, especially for hematologic malignancies. Using recommendations from an expert panel, we suggest DOS patients should be prospectively monitored for hematologic malignancies, which may allow for early intervention and permit its natural history to be better defined.