versión impresa ISSN 0036-4665
Rev. Inst. Med. trop. S. Paulo v.42 n.3 São Paulo mayo/jun. 2000
GALLIUM-67 IMAGING IN A PATIENT WITH PARACOCCIDIOIDOMYCOSIS: A CASE REPORT
Ana Beatriz Marinho de Jesus TEIXEIRA, Elba Cristina Sá de Camargo ETCHEBEHERE, Mariana Cunha Lopes de LIMA, Allan de Oliveira SANTOS, Bruno Cunha PIRES, José Telmo VALENÇA JR., Celso Darío RAMOS & Edwaldo E. CAMARGO
A 26 year-old female was admitted with abdominal pain, fever and weight loss. The clinical and laboratory investigations led to the diagnosis of paracoccidioidomycosis. Gallium-67 whole body images correlated well with the clinical course of the disease and with the patient's prognosis.
KEY WORDS: Gallium-67; Paracoccidioidomycosis; Infection; Whole body scintigraphy.
Paracoccidioidomycosis (South-American blastomycosis) is a disease caused by the dimorphic fungus Paracoccidioides brasiliensis, which was first described in 1908 by Lutz. Based on its pathogenesis the disease may be classified in the following forms: regressive (asymptomatic infection and primary pulmonary), progressive juvenile type (acute and subacute; pulmonary or disseminated) and progressive adult type (chronic; pulmonary or disseminated)4. Microscopic observation of P. brasiliensis in clinical samples and its isolation in culture are the most important diagnostic findings10. The double immunodiffusion and complement fixation serologic tests applied to paracoccidioidomycosis, which are the most commonly used, have allowed its early diagnosis and made it possible to manage the disease appropriately8. Radiological imaging of the skeleton, gastrointestinal tract and lungs have been used in the diagnosis and follow-up of these patients1,2. Whole body gallium-67 scintigraphy has not been used routinely in the diagnosis and follow-up of patients with this disease.
The purpose of this report is to describe the whole body gallium-67 scintigraphic findings in a patient with paracoccidioidomycosis (juvenile disseminated form), with an atypical clinical course.
A 26 year-old farm worker female was admitted to the Campinas State University Hospital with a three-month history of abdominal pain, fever and weight loss. She presented with left cervical, bilateral axillary and inguinal lymphadenopathy and a 10x10 cm mass in the right upper quadrant of the abdomen.
Chest radiograph was normal. Abdominal computed tomography and ultrasound showed massive ascites, retroperitoneal adenomegaly and thickening of the intestinal walls of the mid abdomen. Endoscopy revealed a fistula with a purulent secretion between the first and second portions of the duodenum.
Paracoccidioides brasiliensis was demonstrated in the direct microscopic examination of the duodenal secretion and the duodenal biopsy demonstrated Paracoccidioides brasiliensis (Fig. 1) as well as active chronic duodenal infection. Direct Ziehl-Neelsen microscopic examination was negative for acid-fast bacilli, and the Lowenstein-Jensen culture was negative for M. tuberculosis. Gomori-Grocott smears stains showed multiple budding yeast cells, characteristic of P. brasiliensis in the fine needle aspiration biopsy of the cervical lymph node. The ELISA anti-HIV serologic test was negative. The double immunodiffusion serologic tests for paracoccidioidomycosis were always negative.
Whole body gallium-67 scintigraphy (Fig. 2) revealed increased uptake in the abdomen, involving the peritoneum and intestinal wall, and in the left posterior cervical lymph nodes. These findings were interpreted as active disease.
Therapy was initiated with oral administration of sulfametoxazol-trimetoprim. Initially there was a good response that was followed by a significant clinical worsening. The patient presented several episodes of ascites. She was hospitalized and submitted to multiple large-volume paracenteses; cultures of the ascitic fluid were always negative for fungi (including P. brasiliensis) and mycobacteria. Amphotericin B therapy was started on (total dose: 4 g). Creatinine serum levels became high and the patient began with a milky secretion attributed to the long term use of metoclopramide. A new whole body gallium-67 scintigraphy (Fig. 3) demonstrated active disease in the lungs and abdomen. There was also increased uptake of the radiotracer in the kidneys and breasts which were interpreted as nefrotoxicity caused by amphotericin B and stimulation of the breasts by metoclopramide, respectively.
Thirty eight months after diagnosis and beginning of treatment, the patient was submitted to an exploratory laparotomy which showed a retroperitoneal mass. Biopsy demonstrated P. brasiliensis by Periodic acid-Schiff stain and Gomori-Grocott techniques.
In spite of appropriate therapy, which also included the association of itraconazole, the patient did not improve. The patient died 46 months after the diagnosis with septicemia due to Candida albicans (three positive blood cultures) and disseminated intravascular coagulation. Necropsy demonstrated disseminated paracoccidioidomycosis, with multiple spherical microorganisms and a large number of buds in the lungs and mesenteric lymph nodes.
Gallium-67 citrate is a radiopharmaceutical that shows increased uptake in foci of inflammatory and infectious diseases and several malignant tumors. Gallium-67 scintigraphy has proven useful in the investigation of patients with fever of unknown origin, patients with suspected osteomyelitis and patients with impaired immunocompetence3,11,12. It accumulates in infections caused by pyogenic bacteria, mycobacteria and fungi.
The use of gallium-67 scans in patients with paracoccidioidomycosis and other mycosis has already been described5-7,9. GIORGI et al.9, studying 13 patients with confirmed diagnosis of paracoccidioidomycosis, have shown that whole body gallium-67 imaging is a useful tool for detection of suspected and unsuspected lesions of paracoccidioidomycosis and helps to evaluate the response of the disease to specific therapy. These authors have shown good correlation between whole body gallium-67 scintigraphy and the clinical and laboratory findings. In some cases whole body gallium-67 scintigraphy was even more sensitive than the other methods for the diagnosis of lesion sites (e.g. gallium-67 imaging detected a brain lesion in one of the patients despite of normal CSF and neurologic examination; after appropriate therapy the follow-up study was normal).
In this case report there was also a good correlation between gallium-67 imaging and the clinical history and prognosis. The areas of persistently increased tracer uptake correlated well with the patient's poor response to the treatment, which lead to her death.
Pesquisa de corpo inteiro com gálio-67 em uma paciente com paracoccidioidomicose: relato de caso
Paciente do sexo feminino de 26 anos foi internada com dor abdominal, febre e emagrecimento. A investigação clínico-laboratorial estabeleceu o diagnóstico de paracoccidioidomicose. Os achados cintilográficos com citrato de gálio-67 correlacionaram-se com o curso clínico da paciente.
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Received: 24 August 1999
Accepted: 18 April 2000
Division of Nuclear Medicine, Department of Radiology and Department of Pathology, Campinas State University, Campinas, Brazil.
Correspondence to: Elba Cristina Sá de Camargo Etchebehere, Serviço de Medicina Nuclear do Hospital das Clínicas da UNICAMP, Caixa postal 6142, 13081-970 Campinas, SP, Brazil. Phone : +55-19-2895973. Fax : +55-19-2511041. e-mail: email@example.com