Primary liposarcoma of the right atrium

HUMAN PATHOLOGY

Volume 18, No. 4 [April 1987]

PRIMARY L I P O S A R C O M A OF THE R I G H T A T R I U M LEE L. CAFFERTY, hiD AND JONATHAN I. EPSTEIN MD

Primaly intracardiac liposarcomas are among the rarest tumors of the heart, with a total of six reported cases. The previous reports have focused on clinical features with minimal histologic documentation. We report a primary right atrial liposarcoma showing extracardiac spread and three types of histologic differentiation. This case demonstrated that certain clinical and pathologic features are common to all intracavita U cardiac neoplasms, emphasizing the need for careful hi.~tologic examination. HUM PazttOL 18:408-410, 1987. Primary cardiac tumors are rare entities, with atrial myxomas constituting the vast majority o f cases. Sarcomas account for a p p r o x i m a t e l y 25 p e r cent o f the total; the most c o m m o n types are angiosarcomas and rhabdomyosarconms, and almost all o t h e r types are r e p o r t e d rarely. ~ Primary liposarcomas are a m o n g the most unusual types o f t u m o r o f the heart, with a total o f six r e p o r t e d cases3 -7 Previous reports have concentrated on clinical features and have provided minimal histologic docuntentation in five cases and none in the sixth. We present a prinmry liposarcoma o f the right a t r i u m showing extracardiac spread with emphasis on the gross a n d lfistologic findings. R E P O R T O F A CASE T h e patient was a 57-year-old man who was well until six weeks before admission, when he noticed the gradual onset o f worsening weakness, malaise, and myalgias, followed by the d e v e l o p m e n t o f severe dyspnea, nausea, and

Received September 12, 1986, from the Department of Pathology, The Johns Hopkins Hospital, Baltimore, Maryland. Accepted for publication October 2, 1986. Address correspondence and reprint requests to Dr. Epstein: Department of Pathology, Johns Hopkins Hospital, 600 N. Wolfe Street, Baltimore, MD 21205. 0046-8177/87 $0.00 + .25

FIGURE 1. Large polypoid tumor attached to atrial septum and posterior wall and protruding into atrial caviJy. Tumor shows both gelatinous and firm components.

anorexia. A n extensive work-up was noncontributory until a two-dimensional echocardiogram showed a large rightsided cardiac mass. This mass was noted to prolapse from the right atrium into the right ventricle. Paradoxic septal m o t i o n a n d a m o d e r a t e p e r i c a r d i a l e f f u s i o n w e r e also noted. He was t r a n s f e r r e d the next day to Johns Hopkins Hospital for surgical excision o f the mass. Physical examination on t r a n s f e r was notable for a blood p r e s s u r e o f 130/90, a pulse o f 108 bpm, and a respiratory rate o f 20 breathes p e r minute. Cbest exantination showed hyperinflation and decreased breath sounds in the right base. J u g ular venous distension o f 8 cm with large a waves was noted, as was tachycardia. S~ and $2 were normal, and the a t t e n d i n g cardiologist noted a t u m o r " p l o p " b e f o r e S~. Pulses were 2 + . T h e r e m a i n d e r o f the physical examination was u n r e m a r k a b l e . A n e l e c t r o c a r d i o g r a m s b o w e d sinus tachycardia (rate 140) and b o r d e r l i n e low vohage, a n d a cltest r a d i o g r a p h s showed an e n l a r g e d c a r d i a c shadow a n d focal right lower lobe atalectasis. Adnfission laboratories were noted for markedly low platelets (22 k), slight elevation in leukocyte count (10.2 k), and slight elevation o f s e r u m liver enzyme levels and p r o t h r o m b i n time (SGOT 44, S G P T 34, PT 13.5). Arterial blood gas levels were normal. T h e patient was believed to have a large right atrial myxonm with secondary liver congestion. His thrombocytopenia was thought to be secondary to his myxoma, possible t h r o u g h consumptive processes. A r e p e a t echocard i o g r a m a n d u r g e n t surgery were scheduled, and a hematology work-up was in progress. Although the patient was d o i n g well, wtfile speaking on the telephone to iris wife, he suffered c a r d i o p u l m o n a r y arrest and died. AUTOPSY FINDINGS At autopsy, the heart was notable for a large (6 x 4 x 4.5 cm) friable t u m o r in the posteromedial right atrium. Most o f the t u m o r had a mucinous o r myxoid appearance, but o t h e r areas were firm with a mottled yellow and red

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FIGURE 2. Primary tumor showing CA] myxoid differentiation with prominant delicate plexiform capillary pattern and abundant myxoid material Cx 145]; [B] round cell area with high celtularity, scattered mitotic figures and vocuotated celts [ x 290), and [C] pIeomorphic differentiation; note bizarre mitosis [arrow] and scattered vacuolated cells (x225]. CA//,hematoxylin-eosin stain.)

CASE STUDIES

color (fig. 1). T h e t u m o r was attached to the interatrial septum and posterior walls of the right atrium anti caused t h e s e walls to bulge outward, giving the atrium a domed appearance. A large portion of the t u m o r protruded into the atrial cavity, and the intracavitary border had an uneven edge. A large (10 x 6 • 2.5 cm), fragmented t u m o r e m b o l u s c o m p o s e d almost e n t i r e l y of p i n k gelatinous, myxoid material was present in the proximal main pulmonary artery. Additional t u m o r emboli were found in the right lower lobar artery and in the subsegmental pulmonary arteries. Several associated acute pulmonary infarcts were f o u n d in the right lower lobe. Microscopically, the t u m o r showed diverse patterns. Most of the t u m o r showed myxoid differentiation (fig. 2A), with the classic delicate plexiform capillary pattern a n d scattered lipoblasts. Large areas of r o u n d cell d i f f e r e n t i a t i o n with multiple mitotic figures were also noted (fig. 2B), as were several areas of pleomorphic differentiation (fig. 2C) with many m u h i n u cleated cells, marked nuclear atypia, and multiple mitotic figures. Lipoblasts were seen in all three t u m o r types. T h e t u m o r microscopically infiltrated the atrial nmsculature. Extensive necrosis, especially o f the myxoid areas, was noted. T h e surfaces of the t u m o r showed extensive deposition of hyaline material consistent with fibrin and aggregated platelets. A single metastasis with a fairly b l a n d myxoid appearance was noted in the vertebral cohunn.

is also considered characteristic of myxoma, but again is nonspecific and may represent any one of many other cardiac t u m o r types, including primary sarcomas or metastatic tumors of various types. While cardiac sarcomas classically are thought to diffusely infiltrate and thicken the myocardium, many different types of primary cardiac sarcomas, including rhabdomyosarcoma, angiosarcoma, extraskeletal osteosarcoma, 1 chondrosarcoma, t5 a n d liposarcoma (in o u r case), have been r e p o r t e d to have intracavitary components. Even a p r e d o m i n a n t l y myxoid gross appearance is not diagnostic o f myxoma, as sarcomas with p r o m i n e n t myxoid components, such as myxoid chondrosarcoma is or this case o f liposarcoma, may appear grossly myxoid. Thus, any t u m o r with a clinical presentation a n d gross appearance "classic" for myxoma, such as this case, should be considered merely an intracavitary t u m o r of n n k n o w n histologic type. As it may represent an)' n u m b e r of cardiac tumors, careful histologic examination will be necessary to determine the exact type of tumor. Finally, this patient suffered a precipitous unexpected death by massive p u l m o n a r y t u m o r embolus. Such a means o f death has b e e n r e p o r t e d previously in myxoma. Although rare, this type of misfortune indicates the importance of u r g e n t surgical excision of any large floppy cardiac tumor, as even resection of sarcomas metastatic to the h e a r t have r e s u l t e d in l o n g - t e r m survival in some instances, s.9

DISCUSSION Liposarcomas involving the heart may be of diverse etiologies. Several examples of liposarcoma of the extremities metastatic to the heart have been reported where surgical resection of the cardiac tumors has been attempted. 8,0 Liposarcomas can also involve the heart by direct extension from a mediastinal or pericardial primaryJ ~ Several malign a n t mesench)'momas of the heart, composed of two or more sarcomatous d e m e n t s , have also been described as having liposarcoma as a component, nau Primary intracardiac liposarcomas are extremely rare tumors, with only five illustrated cases reported. 3-7 These cases were poorly documented histologically, concentrating on clinical features. T h e current case showed three classic histologic patterns of liposarcoma (myxoid, r o u n d cell, a n d pleomorphic) in different areas of the large right atrial primary, establishing the diagnosis clearly. This case, while representing a rare cardiac tumor, also illustrates that the clinical a n d some gross features of intracavitary cardiac tumors may be identical regardless of the nature of the neoplasm. Clinically, a " t u m o r plop" and an echocardiographic picture o f a large atrial t u m o r attached to the atrial septnm a n d flipping in and out of the ventricle are usually considered characteristic of myxoma. As shown by this case, however, these features are not specific for myxoma but may be seen with cardiac tumors of any histologic type that have a p r o m i n e n t intracavity component. Thrombocytopenia, as seen in this case, is a n o t h e r feature previously reported in myxomas ts,t4 (and in this case, considered characteristic o f myxoma). It probably represents merely a manifestation of the ifitracardiac n a t u r e of the myxoma. This p h e n o m e n o n could be explained by a platelet consumptive process. T h e gross appearance of a bulging intracavitary t u m o r

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REFERENCES 1. McAllister HA, FenoglioJJ: Tumors of tile cardiovascular system. Armed Forces Institute of Pathology, fascicle 15, Washington,DC, 1978 2. Fletcher FW: Prinmrycardiac tumors. A review of cases at the State University of Iowa Hospitals since 1950. J Iowa Med Soc 53:545, 1963 3. Case records of tile Massachusetts General Hospital. N EnglJ Med 285:1016, 1971 4. Blake S, Kealy '~,~, O'LoughlinS: Liposarcomaof the right atrium. J Irish Med Assoc65:106, 1972 5. NiliM, Arditi S, ttalevi A, et al: Atrialtumors--surgicalexperienceof 9 cases. ScandJ Thorac CardiovaseSurg 17:93, 1983 6. Murtra M, Mestres CA, Igual A, et al: Primaryliposarcomaof the right ventricleand pulmonaryartery: surgicalexcisionand replacementof the pulmonic valve by a Bjork-Shileytilting disc valve.Thorac Cardiovasc Surg 31:172, 1983 7. NzayinambahoK, Noel H, Brohet C, et ah Primarycardiac liposarcoma simulating a left atrial myxoma. Thorac Cardiovasc Surg 33:193, 1985 8. MavroudisC, Way LW, Lipton M, et al: Diagnosisand operative treatment of intracavitaryliposarcoma of the right ventricle.J Thorac Cardiovasc Surg 81:137, 1981 9. RavikumarTS, Topulos GP, AndersonRW, et al: Surgicalresection for isolated cardiac metastases.Arch Surg ! 18:117, 1983 10. Schweitzer DL, Aguam AS: Primaryliposarcomaof the mediastinum. Report of a case and review of the literature.J Thorac Cardiovasc Surg 74:83, 1977 11. StemmermannGN, Kim PM, Berk ME: Malignantmesenchylnomaof the heart. Report of a case. Lancet 85:213-217, 1965 12. Tanaka T, Bunai Y, NishikawaA, et ah Malignantmesenchymomaof the heart. Acta PatholJpn 32:851, 1982 13. Burns ER, SchulmanIC, Murphy MJ: Hematologicmanifestationsand efiologTof atrial myxoma.AmJ Med Sci 284:17, 1982 14. Vuopio P, Nikkila EA: Hemolyticanemia and thrombocytopeniain a case of left atrial myxomaassociated with mitral stenosis.Am J Cardiol 17:585, 1966 15. Hammond GL, Strong WW, Cohen LS, et al: Chondrosarcomasimulating malignant atrial myxoma.J Thorac Cardiovasc Surg 72:575, 1976