Cerebral embolization associated with parenchymal seeding of the left atrial myxoma: Potential role of interleukin-6 and matrix metalloproteinases.

Systemic embolization has been reported in up to 40% of patients with left atrial myxoma, half of them with cerebral involvement. However, development of intracerebral embolization associated with parenchymal seeding of the myxoma emboli is an extremely rare complication, with only 36 histologically diagnosed cases reported in the published literature. We describe a 69-year-old woman who arrived at the emergency service with hemiparesis associated with drug-resistant epilepsy and a medical history of resection of a left atrial myxoma 10 months previously. Cranial computed tomography revealed multiple large lesions of heterogeneous density and cystic components in the occipital lobes and posterior fossa parenchyma. Histopathological analyses after stereotactic biopsy of the occipital lesion revealed infiltrative myxoma cells with benign histological findings and uniform expression of calretinin similar to that of the primary cardiac myxoma. Additional immunohistochemical studies confirmed brain parenchymal seeding of the myxoma cells with strong expression of interleukin-6 (IL-6) and focal expression of matrix metalloproteinases-2 (MMP-2). Here, we discuss the clinicopathological features of intracerebral embolization of left atrial myxomas associated with progressive parenchymal seeding of the tumor emboli and the potential pathogenic role of IL-6 and MMPs.

Primary cardiac angiosarcoma - a review.

Primary cardiac neoplasms are extremely rare. Angiosarcoma is the most commonly seen histological subtype and is characterized by its permeating and destructive nature. Unfortunately, primary cardiac angiosarcoma is often overlooked as an initial diagnosis because of its rarity. Since the time it was first identified in 1934, little progress has been made in improving survival outcome. Complete or partial surgical resection is still the best option for palliation, with little hope for cure. Improvements have been made in the ability to view and distinguish tumors. Echocardiography is one of the most useful diagnostic tools because of its high sensitivity; therefore, CT and MR images are often used to detect sites of metastatic disease. Immunohistochemistry staining can also be employed as an adjunctive diagnostic tool. CD31, CD34, FLI-1, and von Willebrand factor are the most commonly used markers in detecting tumors of endothelial origin. However, due to the vast heterogeneity within a tumor, immunohistochemistry staining can be quite variable. Surgical resection remains the standard modality of treatment. Primary cardiac angiosarcoma is largely resistant to chemotherapy and/or radiation. However, the exact benefit and its place in a multimodality treatment regimen are still under investigation.

Cardiac rhabdomyomas exhibit a fetal pattern of atrial natriuretic peptide immunoreactivity.

Rhabdomyomas are the most common heart tumors seen in infancy. However, whether they represent hamartomas or true neoplasms derived from cardiomyocytes is still controversial. The fetal pattern of atrial natriuretic peptide (ANP) expression (predominant in the atrial and ventricular subendocardium) becomes altered during the early postnatal period to that typical of the adult (all atrial cardiomyocytes and some cells in the ventricular impulse-conducting system). To better comprehend the nature and origin of cardiac rhabdomyomas, we investigated the immunohistochemical expression of ANP in seven surgically excised ventricular specimens and two necropsy cases of multiple, atrial, and ventricular rhabdomyomas in children aged 1 to 34 days. Immunogold labeling for ANP at the ultrastructural level was also performed on three ventricular tumors. Although all atrial tumors were immunoreactive for ANP, these usually showed a variable number of faintly positive cardiomyocytes, contrasting with the diffuse and intense immunoreactivity of the surrounding atrial myocardium. ANP was detected in the ventricular tumors of five (56%) of the nine cases. The positive ventricular tumor cells predominated in the subendocardium and areas with prominent fibrous tissue, usually around blood vessels. Immunoelectron microscopy of the ventricular tumors demonstrated rare, positive cytoplasmic granules surrounded by membranes, usually located near the nuclei. We conclude that cardiac rhabdomyomas exhibit a fetal pattern of ANP immunoreactivity, which suggests delayed maturation of the tumoral cardiomyocytes, reinforcing the notion that cardiac rhabdomyomas are fetal hamartomas.