D. Balièeviæ et al. Esophageal hemangiopericytoma or hemangiopericytoma-like tumor Acta clin Croat, Vol. 43, No. 3, 2004 '! Acta Clin Croat 2002; 43: Case Report ESOPHAGEAL HEMANGIOPERICYTOMA OR HEMANGIOPERICYTOMA-LIKE TUMOR: A CASE REPORT AND REVIEW OF THE LITERATURE Drinko Balièeviæ 1 , Irena Novosel 2 , Davor Tomas 1 , Davor Hrabar 3 , Ahmed Pirkiæ 1 and Mladen Belicza 1 1 Ljudevit Jurak University Department of Pathology, Sestre milosrdnice University Hospital, Zagreb; 2 Department of Pathology, Dr. Ivo Pediiæ County Hospital, Sisak; 3 Department of Gastroenterology, Sestre milosrdnice University Hospital, Zagreb, Croatia SUMMARY  Hemangiopericytoma is a rare malignant vascular tumor deriving from pericytes. It usually occurs in the extremities and retroperitoneum, and extremely rarely in the gastrointestinal tract. A case of hemangiopericytoma in the gastroesophageal region is reported. A 56-year-old man was treated with H2- receptor antagonist for dyspeptic symptoms that had occurred three months before. Therapy failed to prove successful and gastroendoscopy was performed in March 2001 to reveal slightly reddish ventricular mucosa with normal rugal folds and a sessile, polypoid, grayish mass of rough surface located at the gastroe- sophageal junction. Histopathologic examination of polypoid mass samples revealed a vascular tumor cov- ered with squamous epithelium. The hallmarks of the tumor were numerous branching, slit-like capillary channels with staghorn appearance, and large gaping sinusoidal spaces enclosed within nests of ovoid cells. Vascular invasion, mitotic activity, giant cells and necrosis were not found. Immunohistochemical analysis showed diffuse and strong reactivity for vimentin and focal, low or moderate reactivity for actin, S-100 and smooth muscle actin. Proliferation index measured by PCNA and Ki-67 ranged from 2% to 13% (median 11.2%) and from 5% to 18% (median 7.6%), respectively. A diagnosis of hemangiopericytoma with low malignant potential was made. Almost two years of the intervention, the patient is alive and free from any signs of tumor spread. Key words: Esophageal neoplasms  pathology; Hemangiopericytoma  pathology; Hemangiopericytoma  immunochem- istry Correspondence to: Drinko Balièeviæ, M.D., Ph.D., Ljudevit Jurak Univer- sity Department of Pathology, Sestre milosrdnice University Hospital, Vinogradska c. 29, HR-10000 Zagreb, Croatia Received March 5, 2003, accepted in revised form May 28, 2004 Introduction Hemangiopericytoma (HP) is a rare malignant vas- cular tumor deriving from Zimmermanns pericytes 1 . It is almost always a solitary and solid tumor with smooth surface, its color ranging from grayish-white to reddish- brown. In three fourths of cases, the tumor is well cir- cumscribed and encapsulated. In spite of that, surgical excision may be difficult because of profuse bleeding, and re-exploration is occasionally needed. HP metasta- sizes to the lungs, bone and liver in approximately 50% of patients. It is a tumor of adults, median age 45, and rarely affects infants and children. The tumor shows an equal sex involvement 1,2 . HP may occur as a slowly growing, deep seated, pain- less mass at any anatomic site, however, lower extrem- ities, pelvic fossa, retroperitoneum, head and neck, trunk and upper extremities are most commonly affect- ed. It can also be found in subcutaneous tissue. Rare cases of lipomatous HP, meningeal HP, HP of the nasal passages and paranasal sinuses, orbital HP, and HP of miscellaneous sites are on record 1,2 . HP is extremely rare in the gastrointestinal tract, and only three cases of esophageal HP have been reported in recent literature 3-5 . The most common localization of HP in the gastrointes- tinal tract was stomach, and only few isolated cases of ileum, colon and rectum involvement have been de- scribed 6-12 .