Extracutaneous intravascular histiocytosis of the aortic valve: Report of two cases

From the archives of MD Anderson Cancer Center. Mesothelial/monocytic incidental cardiac excrescence with a review of the literature

Mesothelial/monocytic incidental cardiac excrescence (MICE) is a rare benign lesion composed of monocytes and mesothelial cells that is most often encountered during cardiothoracic surgery. We describe a case in a 71-year-old man with known aortic valve stenosis who presented with gradual onset dyspnea over a few weeks, made worse with minimal exertion. A transesophageal echocardiogram revealed severe aortic stenosis and mild pericardial effusion. The patient underwent aortic valve replacement, coronary artery bypass, and amputation of the left atrial appendage. Histological examination of a 0.8 cm blood clot received along with the atrial appendage showed an aggregation of bland cells with features of monocytes associated with small strands and nodules of mesothelial cells, fat cells, fibrin and a minute fragment of bone. Immunohistochemical analysis showed that the monocytic cells were positive for CD4 and CD68 (strong) and negative for calretinin and keratin. By contrast, the mesothelial cells were positive for calretinin and keratin and negative for all other markers. In sum, the morphologic and immunohistochemical findings support the diagnosis of MICE. Based on our review of the literature, about 60 cases of MICE have been reported previously which we have tabulated. We also discuss the differential diagnosis.

Lymphocyte-rich capillary-cavernous hemangioma of the mitral valve: a case report and review of the literature

Valvular hemangioma incidence is extremely low. In this report, we describe a 62-year-old man who presented with mild edema of the lower limbs. An echocardiogram revealed an incidental 1.3-cm diameter mass on the anterior mitral valve leaflet for which he underwent surgical resection and mitral valve replacement. Histopathological examination showed a lymphocyte-rich capillary-cavernous hemangioma. The exuberant lymphoid stroma is unusual for hemangioma and represents an undescribed pattern of cardiac hemangioma. Including the present report, only 13 cases of mitral valve hemangioma have been reported to date. Most patients are adult. Mitral hemangioma originates in the atrial aspect of the valve and involves more commonly the anterior leaflet. The average maximum diameter of the lesion is 1.7 (S.D.=0.75) cm. Pure cavernous hemangioma is the predominant type of mitral hemangioma. Most of them are described as pedunculated or polypoid. Surgical excision appears to be curative. Recurrences have not been reported. Lymphocyte-rich cardiac hemangioma represents a peculiar type of hemangioma which should be included in the differential diagnosis of other vascular lesions.

Intralymphatic Histiocytosis of the Appendix and Fallopian Tube Associated With Primary Peritoneal High-Grade, Poorly Differentiated Adenocarcinoma of Müllerian Origin

Intralymphatic histiocytosis (ILH) is a peculiar pathological process characterized by the collections of benign histiocytes in dilated lymph vessels. Although the majority of ILH patients present clinically with various forms of cutaneous manifestation, rare extracutaneous incidences have been reported in the literature. To date, ILH has not been described in an internal visceral organ. We report the case of a 68-year-old woman who underwent an appendectomy during a surgical procedure for a primary peritoneal high-grade, poorly differentiated adenocarcinoma of Müllerian origin. Although no malignancy was identified in the appendix, the appendiceal mucosa and submucosa were expanded by dilated vascular channels harboring aggregates of uniform epithelioid cells. Similar histological changes were also identified in the right fallopian tube. Immunohistochemical studies revealed the lymphatic nature of the vessels and the histiocytic origin of the intravascular cells. Of note was the presence of scattered multinucleated giant cells in the histiocytic population, a histological feature not described hitherto in ILH. To the best of the authors' knowledge, this is the first case of ILH harboring multinucleated giant cells, involving internal visceral organs, and associated with a malignant tumor of the gynecological system. As such, the current case report expands the clinical and histological spectrum of ILH.