TEN-YEAR-OLD BOY WITH HEMANGIOPERICYTOMA AND HUMAN IMMUNODEFICIENCY VIRUS INFECTION

This report documents the first case of hemangiopericytoma in an HIV-infected child who is most likely a case of vertical transmission of HIV with slow progression to AIDS. We also raise the possibility that there is a causal relationship between HIV and hemangiopericytoma. Hemangiopericytoma is a rare tumor, accounting for ∼3% of all soft tissue sarcomas in children. 1 Soft tissue sarcomas account for 7% of all newly diagnosed cancer in patients <15 years of age. 2 Hemangiopericytomas are ubiquitous with regard to both age distribution and location in the body. In the central nervous system they are often subclassified as a type of meningioma. 3 At present only one case of hemangiopericytoma in an HIV-infected patient has been reported. 4 We report a case of a Thai boy who presented with new onset paraparesis and was diagnosed with hemangiopericytoma and AIDS. Case report. A 10-year-old Thai boy was admitted to Chulalongkorn University Hospital on December 10, 1999. Three days earlier he experienced the onset of numbness in his lower extremities, first on the left and then on the right. This was followed closely by bilateral lower extremity weakness which progressed until the day of admission, at which time he could no longer ambulate independently. He also had a loss of bladder control on the day of admission. The patient had been previously healthy with no significant past medical history. The patient denied any preceding viral illness, trauma, blood transfusions and intravenous drug use. He had never been hospitalized and was receiving no medications. The patient currently lives with his aunt and uncle. The patient’s parents are deceased with the causes of death unknown to the uncle. Physical examination on presentation revealed a 10-year-old boy who was alert and oriented. His weight was 22 kg (10%) and his height was 118 cm (<3%). His temperature was 36.4°C, heart rate 118/min, blood pressure 121/90 mm Hg and respiratory rate 22/min. Motor power was 5/5 in the upper extremities and 0/5 in the lower extremities. Sensory examination was notable for decreased sensation to pain and temperature below the level of T4. Deep tendon reflexes were 2+ at the upper extremities and 4+ at the lower extremities bilaterally. Babinski sign was present bilaterally. Rectal examination was significant for moderately decreased sphincter tone. Other abnormalities on physical examination were mild neck stiffness, right cervical and axillary lymphadenopathy and a generalized, hyperpigmented, papular rash on his trunk and all four extremities. Imaging studies included chest radiograph and magnetic resonance imaging (MRI). The chest radiograph revealed a soft tissue opacity overlying the right tracheobronchial junction, about 3 cm in diameter, which interpreted as either adenopathy or a right paraspinal mass. The MRI showed a 2- by 2-cm soft tissue density extradural mass at the level of T4, which was compressing the spinal cord (Fig. 1).Fig. 1: MRI of thoracic spine showed 2- by 2-cm extramedullary intradural hypervascular mass with central necrosis at T2-T4 level which compressed the spinal cord.Laboratory examination showed p24 antigenemia. CD4 count and HIV-RNA viral load were 1% (3/mm 3) and >500 000 copies/ml (log10 > 5.7 copies/ml), respectively. The patient underwent a laminectomy at T3 to T5 with complete resection of the extradural tumor. Grossly the surgical specimen was a gray-white, firm mass measuring 2.0 by 1.5 by 1.2 cm. Sectioning revealed homogeneous gray-white cut surfaces. Histologically the specimen was a monotonous cellular tumor composed of plump and polygonal cells with scant, ill-defined cytoplasm. The cellularity of the tumor was interrupted by patches of hypocellularity. The reticular staining showed a dense intercellular pattern. The tumor lacked epithelial membrane antigen activity. The final diagnosis was extradural hemangiopericytoma. After tumor resection the patient regained full neurologic function. He received a course of radiation therapy, and antiretroviral therapy was initiated. The patient’s hospital course was complicated by two episodes of chickenpox and one episode of bacterial pneumonia. Discussion. This case raises several issues worthy of comment. First this is most likely a case of vertical transmission of HIV. In the absence of other risk factors and with a history of both parents dying at a young age of unknown illnesses, this suggests the situation of parental HIV infection with vertical transmission to the patient. Second if this is a case of vertical transmission of HIV, then it is also notable for its slow progression to AIDS. One study showed that by 2 years of age, 46.7% of untreated, vertically infected children with HIV are symptomatic, whereas the rest remain asymptomatic. 5 This patient was 10 years old before he developed symptoms related to HIV: recurrent chickenpox, pneumonia and hemangiopericytoma. Third this case is notable for the coincidence of HIV infection and malignancy in the same patient. Malignancy in pediatric AIDS is relatively rare compared with adult AIDS. As of December, 1996, only 2% of pediatric AIDS patients age 13 years or younger reported to the CDC were known to have a malignancy. 6 However, it is expected that the incidence of malignancy in pediatric AIDS will increase as better treatment of opportunistic infections enables children with AIDS to survive longer. If hemangiopericytoma in this patient is an opportunistic malignancy, then this case supports this expectation. A fourth issue is whether hemangiopericytoma is an incidental finding in this patient or whether it is related to the patient’s HIV infection. A review of the literature to investigate the possibility of a causal relationship between HIV and hemangiopericytoma yielded one case report of hemangiopericytoma in a patient with HIV. In several case series and registry linkage studies of cancer in HIV-infected patients, there were no reports of hemangiopericytoma. 6–10 However, two registry linkage studies reported increased incidence of unspecified soft tissue sarcomas in one and increased incidence of connective tissue tumors in the other. 7, 10 Hemangiopericytoma can be classified under either of these headings. The case report was that of a 33-year-old man known previously to be HIV-positive with a CD4 count of 18.9/mm 3 who presented with an oropharygeal mass which was a hemangiopericytoma. 4 Both this patient and our case report had AIDS-defining conditions at the time they were diagnosed as hemangiopericytoma, a finding consistent with the possibility that there is a causal relationship between HIV and hemangiopericytoma. Mechanisms proposed previously for the pathogenesis of cancer in HIV-infected patients include direct oncogenic effects of HIV, oncogenic effects of other viruses such as Epstein-Barr virus and human herpesvirus 8 and decreased immune surveillance as a consequence of the destruction of the immune system by HIV. 10 It is now known that HIV-infected patients are at increased risk of developing malignancies other than the prototypical AIDS-defining Kaposi’s sarcoma and non-Hodgkin’s lymphoma. In adults these non-AIDS-defining malignancies include Hodgkin’s disease, multiple myeloma, seminoma, squamous cell carcinoma of the anus, cervical carcinoma, basal cell carcinoma, non-small cell and small cell lung carcinoma, malignant melanoma and acute and chronic leukemias. 7, 8, 10 In pediatrics AIDS leiomyoma/leiomyosarcoma is the second most common malignancy after non-Hodgkin’s lymphoma. Other associated neoplastic disorders in pediatric AIDS are Kaposi’s sarcoma, leukemia, mucosa-associated lymphoid tissue lymphomas and human papillomavirus-associated genital lesions. 6, 9 As the AIDS pandemic continues and the body of data on AIDS-related cancer grows, association between AIDS and cancers in addition to those listed here will be found. Hemangiopericytoma may be among them.