Gastrointestinal Kaposi's Sarcoma Presenting as Ileocolic Intussusception.

CONTEXT: Kaposi's sarcoma (KS) is the most common neoplasm in patients with acquired immune deficiency syndrome (AIDS). Gastrointestinal (GI) involvement with KS commonly occurs in association with cutaneous lesions or lymph node involvement, with GI tract involvement alone occurring in only 3.5% of cases. There are several case reports described in the literature about asymptomatic intestinal KS with skin manifestations. Although GI KS is usually asymptomatic, hemorrhages from the oral cavity, esophagus, stomach, and large bowel have been reported in this disease. CASE REPORT: Our case is unique, in a way that the patient does not have skin manifestation, and also is that the first manifestation presented as acute intestinal intussusception and obstruction with nodular mass lesions of the stomach and GI tract due to GI KS.
CONCLUSION: As a differential diagnosis of KS, nonHodgkin lymphomas frequently involve the gut in AIDS patients. Furthermore, tumors of the gut with spindle-shaped cells such as leiomyomas, rhabdomyosarcomas, high-grade pleomorphic sarcomas, or GI stromal tumors have to be considered in the differential diagnosis. Overall, the visceral involvement of the KS is usually associated with poor prognosis. Our case illustrates the importance of physicians to recognize GI KS as a differential diagnosis for HIV positive patients with recurrent abdominal pain. It is commonly occurs in association with cutaneous lesions or lymph node involvement and rarely presents with GI involvement alone, which is makes it a challenge to the physician.

Introduction

Our case illustrates the importance of physicians to recognize gastrointestinal (GI) Kaposi sarcoma (KS) as a differential diagnosis for patients with recurrent abdominal pain. It commonly occurs in association with cutaneous lesions or lymph node involvement and rarely presents with GI involvement alone, which makes it a challenge to the physician.

Case Presentation

A 42-year-old male presented with one week history of nausea, vomiting and peri-umbilical abdominal pain of few hours duration. He also had associated nonbloody diarrhea. He denies viral prodrome, sick contacts, recent travel, food poisoning, or any recent antibiotic use. Past medical history was significant for human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS) with last CD4 count of 28 and viral load of 13,949. On physical examination, vital signs were within normal limits except blood pressure of 87/58 mmHg. Abdominal examination was significant for tenderness around peri-umbilical region and in right-lower quadrant without rebound tenderness. Bowel sounds were absent. Initial laboratory work was remarkable for hyponatremia (125 mmol/L) and hypokalemia (3.0 mmol/L). Computed tomography (CT) of abdomen with contrast showed long segment of small bowel that was seen projected into the lumen of a distended mobile cecum consistent with large ileo-colic intussusception [Figure 1a]. It was also noted in several areas of nodular thickening in the gastric wall, small bowel, and ascending colon. Differential diagnosis at that time was tuberculosis, lymphoma, and KS. During the hospital course, patient was treated conservatively; he was kept nothing by mouth (NPO), was given intravenous fluids, and nasogastric suction was placed. Esophagogastroduodenoscopy (EGD) showed esophageal candidiasis and multiple raised erythematous lesions and masses distributed throughout the stomach with ulcerations. The lesions were nodular and polypoid and have a vascular appearance. No bleeding and no stigmata of recent bleeding were noted. The lesions ranged from less than 1 cm to approximately 4 cm in diameter [Figure 2]. Biopsies show KS [Figure 1b and c] and tumor cells were positive for human herpes virus 8 (HHV-8). Patient's symptoms improved with conservative management and he was discharged on highly active antiretroviral therapy (HAART). Two weeks later, the patient was readmitted to our hospital with similar symptoms. Repeat CT-scan showed recurrent ileo-colic intussusception. Small-bowel series showed incomplete small bowel obstruction with spontaneous resolution of intussusception. Patient was discharged to continue HAART therapy and doxorubicin chemotherapy on weekly basis was added to his management.

Figure 1

(a) Computed tomography (CT) scan of the abdomen. Cross-sectional image of the mid portion of intussusception (arrow) illustrates small bowel invagination through the ascending colon just above the cecum. These findings are consistent with ileo-colic intussusception. (b and c) Pathologic examination revealed gastric mucosa with a spindle cell proliferation separating and displacing the gastric glands. The epithelium is somewhat reactive appearing and the background is hemorrhagic. (Panel C) This high power image shows the plump spindle cells and numerous surrounding erythrocytes. The appearance is not high-grade and there are no definite mitoses. These features are highly suggestive of Kaposi's sarcoma

Figure 2

Esophagogastroduodenoscopy (EGD) shows a: Esophageal candidiasis, b: Large masses at greater curvature of the stomach with ulcerations, c: Mass at junction of body and greater curvature of stomach and D: Mass at the fundus of the stomach

Discussion

KS is multicentric and angioproliferative tumor. It was first described by Dr. Moritz Kaposi in 1872.[1] KS is commonly seen in HIV patients and accounts for 60% of overall malignancies and 40% of GI malignancies in patients with AIDS.[1] HHV-8 is considered the main cause of KS in more than 95% of cases.[2] The overall incidence of GI KS is underestimated but accounts for 51% of all KS cases in one study.[3] Since GI KS is observed in 40% of homosexual men at time of AIDS diagnosis and 80% after autopsy, it is believed that sex is the main mode of HHV-8 transmission.[4] Stomach, duodenum, and biliary tract are the most common targeted sites, whereas jejunum, ileum, or large bowels are rarely affected. Skin lesions commonly accompany GI involvement and present in more than 50% of cases. Absence of skin involvement does not rule out GI KS and occurs in 3.5% of cases.[5] Patients with GI KP are usually asymptomatic and found accidently on endoscopy or autopsy but symptoms such as upper or lower GI bleeding, abdominal pain, nausea, vomiting, malabsorption, weight, and/or diarrhea. Complications such as intussusception, perforation, or obstruction have been reported. Our case is unique, in a way that the patient does not have skin manifestation, and also that the first manifestation presented as acute intestinal obstruction with nodular mass lesions of the stomach and GI tract. Since most cases are asymptomatic, diagnosis is usually challenging and occurs late in the course of the disease. Endoscopy is the main diagnostic method, which usually shows lesions vary from ulcers to purple or dark red sub-mucosal nodules overlaid with a thin mucosa. Obtaining sufficient tissue samples is necessary for an accurate diagnosis.[6] Histology usually reveal proliferating spindle cells that are believed to be derived from lymphatic endothelium since they are frequently positive for lymphatic endothelial cell markers such as CD34, CD31, D2-40, and hyaluronan receptor LYVE-1.[7] FHI-1 test (monoclonal antibodies against the carboxyl terminal end of the FLI-1 protein) is usually positive and is helpful to differentiate Kaposi tumor from nonvascular tumors such as rhabdomyosarcomas, desmoplastic small round cell tumors, high-grade pleomorphic sarcomas, and colonic adenocarcinomas.[8] GI-KS should be differentiated from other common disease that attacks the GI tract in HIV patients such as cytomegalovirus, nonHodgkin lymphomas, leiomyomas, rhabdomyosarcomas, high-grade pleomorphic sarcomas, or GI stromal tumors. Treatment of GI KS is palliative and should focus on relieving symptoms and preventing progression. HAART may decrease the production of new lesions, shrink the existing lesions and improve survival with or without chemotherapy, although limited disease can be treated locally with radiotherapy and intralesional chemotherapy. Systemic chemotherapy is usually required for extensive skin or symptomatic visceral involvement.[9] Liposomal anthracyclines (pegylated liposomal doxorubicin or liposomal daunorubicin) are considered first line therapy for systemic KS due to good clinical response rates and less side effects. Generally speaking, visceral (including GI) involvement confers an advanced stage and poor prognosis with a mean survival rate of 4.7 months without HAART therapy.[9]