AJR:188, May 2007 1365 AJR 2007; 188:1365–1366 0361–803X/07/1885–1365 © American Roentgen Ray Society Bhatt et al. Littoral Cell Angioma of Spleen Gastrointestinal Imaging • Radiologic–Pathologic Conference of the University of Rochester School of Medicine and Dentistry Littoral Cell Angioma of the Spleen Shweta Bhatt 1 Jiaoti Huang 2 Vikram Dogra 1 Bhatt S, Huang J, Dogra V Keywords: littoral cell angioma, radiologic–pathologic, spleen DOI:10.2214/AJR.06.1157 Received August 29, 2006; accepted after revision October 31, 2006. 1 Department of Radiology, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave., Box 648, Rochester, NY 14642. Address correspondence to V. Dogra. 2 Department of Pathology, University of Rochester School of Medicine and Dentistry, Rochester, NY. ittoral cell angioma of the spleen is a rare vascular tumor that was first described by Falk et al. [1] in 1991. The tumor arises from the littoral cells in the splenic red pulp sinuses. Littoral cell angioma affects both men and women equally with no specific age predilec- tion. It is usually asymptomatic and is discov- ered incidentally. Some of the patients with this entity may present with symptoms of hy- persplenism such as anemia, thrombocytope- nia, and splenomegaly, the latter seen in al- most all patients with littoral cell angioma. Clinically, a majority of the littoral cell an- giomas described in the literature have been found to be benign in nature, but several re- ports have described malignancy in the lit- toral cell angioma [2]. Definite evaluation can only be done at pathology. Most of the cases of littoral cell angioma described in the literature have been com- posed of multiple nodules of varying sizes in the spleen [2, 3]; only one case of focal angi- oma has been described [4]. Our patient was a 56-year-old man who, while being evaluated for thigh leiomyosar- coma, was found to have splenomegaly with hy- podense splenic lesions. The patient did not show any signs or symptoms of hypersplenism. Unenhanced and contrast-enhanced portal venous phase CT was performed, which re- vealed multiple splenic lesions with enhance- ment (20 H). Because the patient had a history of malignant melanoma and existing thigh leio- myosarcoma, the splenic lesions were suspected to be metastatic in origin. Because of the con- cern for malignancy, a splenectomy was per- formed. Pathology revealed the presence of multiple foci of brown-black friable areas, the largest being 4.5 cm. This lesion extended up to the capsule but did not penetrate it. An immuno- histochemical study confirmed the histologic diagnosis of littoral cell angioma by showing the cells positive for CD31, CD68, and factor VIII. Radiologic Features On CT imaging, littoral cell angioma ap- pears as a hypoattenuating nodule or nodules ranging in size from 5 to 6 cm and demonstrat- ing contrast enhancement on the portal venous phase (Fig. 1A). Delayed phase imaging shows the nodules to become isodense to the sur- rounding splenic parenchyma because of de- layed filling of the nodules [5]. Radiologic find- ings can rarely lead to a definitive diagnosis because many other splenic neoplasms have a similar appearance. Other splenic neoplasms that mimic littoral cell angioma include heman- giomatosis, lymphangiomatosis, hamartoma, hemangiopericytoma, hemangioendothelioma, and angiosarcoma; malignant processes such as metastases, lymphoma, and Kaposi sarcoma; and infectious processes such as Pneumocystis and Mycobacterium [5]. Splenic metastases from malignant mela- noma and leiomyosarcoma, although rare, have been reported. Splenic metastasis from melanoma has an incidence of less than 5%, but the rate is much higher on autopsy (36%) [6]. Sonography is rarely helpful because the findings vary widely. The sonographic fea- tures that can be seen include heterogeneous echotexture without any definite nodules, or the lesions may appear isoechoic, hypo- echoic, or hyperechoic [2]. MRI of the spleen may further help in the diagnosis by showing hypointense lesions on both T1-weighted and T2-weighted scans because of the hemosid- erin content of the tumor. Pathologic Features Definite diagnosis of littoral cell angioma can only be made at pathology after splenec- tomy, which is usually performed because of the concern for malignancy. The gross cut surface of the spleen shows nodules with blood or blood products with a variable color from dark red or brown to black, depending on the chronicity of the L Downloaded from www.ajronline.org by 52.73.204.196 on 05/17/22 from IP address 52.73.204.196. Copyright ARRS. For personal use only; all rights reserved