CASE REPORT Annals of Nuclear Medicine Vol. 2, No. 2, 81-83, 1988 A case of unexpected gallium-67 uptake by sternum in non-hodgkin's lymphoma with pleuritis Hitoya OHTA,* Masaki ISHII,* Tetsuji SAKASHITA,* Hironobu IWASAKI,** Takeshi SHIRAISHI,** Katsuji IKEKUBO,** Keigo ENDO*** and Junji KONISHI*** *Department of Internal Medicine, Kobe Tamatsu Hospital **Kobe General Hospital ***Department of Nuclear Medicine, Kyoto University Hospital A case of non-Hodgkin's lymphoma with pleural effusion was presented. Pleural effusion is not a common manifestation of this disease and 67Ga-citrate scintigraphy gave the clue for the diagnosis. The possibility of malignant lymphoma should be considered in cases with pleural effusion, and we showed that 67Ga-citrate scintigraphy can be useful in a case with pleural effusion of undetermined cause. Key words : Malignant lymphoma, Pleural effusion, 67Ga-citrate, Adenosine deaminase INTRODUCTION PLEURAL EFFUSION is a rather rare manifestation of malignant lymphoma.1 The causes of pleural effusion are varied, but in Japan, we must include tuberculosis in differential diagnosis.2 This report concerns a case of pleuritis in which the misdiagnosis of tuberculosis was made but unexpected 67Ga-citrate (67Ga) uptake by the sternum brought the clue for the correct diagnosis of malignant lymphoma. CASE REPORT A 40-year-old male was admitted to our hospital due to left pleural effusion. The relevant laboratory findings on admission were summarized as follows; complete blood count, blood picture, serum electrolytes, liver and renal function tests were normal. The sedimentation rate was 2 mm in 1 hour, CRP was 7.4 mg/dl. Although cultures of sputa and pleural effusion were negative for tubercle bacillus, the PPD (purified Received March 18, 1987 ; revision accepted August 12, 1987. For reprints contact : Masaki Ishii, M.D., Kobe Tamatsu Hospital, 397-4, Mitani, Tamatsu-cho, Nishi-ku, Kobe 673, JAPAN. protein derivatives) skin test was positive (24 x 20 mm). The pleural effusion was yellowish, turbid and mature lymphocyte dominant, with a high level of adenosine deaminase (ADA) (109 IU/L). Pleuritis tuberculosa was suspected and antituberculous therapy was started. However, in spite of medication for 6 months, the effusion did not decrease and contralateral pleural and pericardial effusion were also recognized (Figs. l, 2). At this time, no malignant cells could be recognized in the peripheral blood or pleural effusion, and pleural biopsy did not give us any useful information. Because of no response to antituberculous therapy and no evidence of the presence of malignant cells by thoracentesis and pleural biopsy, mesothelioma was also considered a possibility. Then 67Ga scintigraphy was performed3,4 and we interpreted the resulting images to mean that there existed unexpected abnormal 67Ga uptake by the whole sternum and hilus pulmonis (Fig. 3 A, B). Consequently bone marrow aspiration of the sternum was performed, and histopathological examination revealed malignant lymphoma (lymphoblastic) (Fig. 4). After chemotherapy with five courses VEPA (Vincristine, Endoxan, prednisolone, adriamycin) in six months, this patient achieved complete remission and subsequent 67Ga scintigraphy showed no abnormal uptake (Fig. 5). DISCUSSION Pleural effusion is not a common manifestation of malignant lymphoma. In this case, because of the character of the pleural effusion, especially high level of ADA5,6 and absence of malignant cells, misdiagnosis of pleuritis tuberculosa was made and ineffective treatment was continued for a rather long time. Retrospectively, enlarged hilar lymph nodes were visible on the chest films and CT scans and malignant lymphoma should have been suspected. It was the unexpected 67Ga uptake by the sternum which led us to bone marrow aspiration. Malignant cells in the pleural and pericardial effusion were proved later. Because of the enlarged hilar lymph nodes shown by chest films and CT scans, abnormal 67Ga uptake by the sternum and hilus, and malignant cells in the pleural and pericardial effusion, clinical diagnosis was corrected to the malignant lymphoma originating from the mediastinal lymph nodes with invasion to the sternum, pleura and pericardium (Stage IV). The usefulness of 67Ga scintigraphy in malignant lymphoma is well known,7 and in this case 67Ga scintigraphy was the best diagnostic procedure, although the enlarged lymph nodes should have been detected sooner. In conclusion, we suggest that the possibility of malignant lymphoma should be kept in mind in cases with pleural effusion. We have demonstrated that 67Ga scintigraphy is useful in the investigation of pleural effusion of undetermined cause. ACKNOWLEDGMENT We wish to thank the editorial board for its valuable advice and Mr. Toru Ohnishi, Mr. Yasuhide Obata and Mr. Bungo Onoue for their assistance in preparing the manuscript. REFERENCES l . Lee YTN, Spratt JS Jr : Malignant lymphoma nodal and extranodal disease. In Modern Surgical Monographs. Egdahl RH (ed), New York, Grune Stratton. 1974, pp 291-31l 2. Kira S, Natori H, Nakamura T, et al: Round table talk : Pleural water. Respiration Research 4 : 1035-1048, 1985 3. Seo IS, Too KG, Carter JE : Demonstration of pleural mesothelioma by gallium scan. Clin Nucl Med 5 : 407-409, 1980 4. Wolk RB : Gallium-67 scanning in the evaluation of mesothelioma. J Nucl Med 19 : 808-809, 1978 5. Piras MA, Gakis C, Budroni M, et al: Adenosine deaminase activity in pleural effusions: An aid to differential diagnosis. Br Med J 2: 1751-1762, 1978 6. Ocana I, Martinez-Vazques JM, Segura RM, et al : Adenosine deaminase in pleural fluids. Test for diagnosis of tuberculous pleural effusion. Chest 84 : 51-53, 1983 7. Hayes RL : The medical use of gallium radionuclides : A brief history with some comments. Semin Nucl Med 8 : 183-191, 1978