Intraventricular Melanoma

Arbelaez et al (1) reported the imaging features of an intraventricular melanoma. They ascribed some regions of T1 hyperintensity to the presence of stable free radicals within melanin. According to Enochs et al (2), melanin bound Fe3⁺ is the major contributor to melanin 1/T1 in clinical conditions. The authors fail to mention that melanin-associated T1 hyperintensity is seen only in melanotic melanomas (3, 4). Neither their operative description of a “…dark greenish and brown mass…” nor their pathologic section and description “…scattered neoplastic cells displayed dusky brown intracytoplasmic pigment (Fig H)…” support the diagnosis of a melanotic melanoma. The authors did not observe any hemorrhage and failed to mention the frequency of hemorrhage in melanoma (4) and its possible contribution to the T1 hyperintensity of their case. This is especially significant in their case because of the clear evidence of a layer of red blood cells in the associated left occipital horn (Ref 1, Figure 1) with combined CT and MR properties of intracellular deoxyhemoglobin. In addition, there are CT and MR imaging suggestions of a similar hematoma in the posterior part the intraventricular tumor. The intraventricular hemorrhage and probable intratumoral hemorrhage may have also contributed to the patient's headache.