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doi:
10.4103/ijnm.ijnm_38_24
Unexpected Extrarenal Accumulation of Tc-99m Ethylene Dicysteine in a Case of Liposarcoma
1Department of Nuclear Medicine, School of Medicine, Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
2Department of Nuclear Medicine, School of Medicine, Hasheminejad Hospital, Iran University of Medical Sciences, Tehran, Iran
3Department of Molecular Imaging, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
Address for correspondence: Dr. Leila Hassanzadeh, Department of Nuclear Medicine, School of Medicine, Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Shahid Hemmat Highway, Tehran 14496-14535, Iran. E-mail: hassanzadeh.l@iums.ac.ir
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Received: ,
Accepted: ,
Copyright: © 2024 Indian Journal of Nuclear Medicine
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This article was originally published by Wolters Kluwer - Medknow and was migrated to Scientific Scholar after the change of Publisher.
This article was originally published by Wolters Kluwer - Medknow and was migrated to Scientific Scholar after the change of Publisher.
Abstract
The technetium-99m ethylene dicysteine (Tc-99m EC) is a radiopharmaceutical used for renal scintigraphy, a noninvasive imaging technique that assesses kidney function as well as urinary tract obstruction. We describe the extrarenal Tc-99m EC uptake in a 70-year-old man with recurrent well-differentiated abdominal liposarcoma. In the present case, both liposarcoma lesions which were diagnosed by abdominal CT scan showed heterogeneous accumulation of the Tc-99m EC.
Keywords
Ethylene dicysteine
liposarcoma
technetium-99m ethylene dicysteine
well-differentiated
![A 70-year-old male patient, with uncontrolled hypertension despite antihypertensive medications, underwent technetium-99m ethylene dicysteine (Tc-99m EC) scintigraphy before and after captopril administration to evaluate potential renovascular hypertension.[1] However, the assessment ruled out the suspected diagnosis. Interestingly, pre- and postcaptopril Tc-99m EC scanning disclosed accumulation of the radiotracer in the left perirenal space (c: black arrow and b: black arrowhead). A photopenic area, corresponding to heterogeneous uptake on posterior views (c: null arrow), was seen on the left side of the bladder on dynamic images. For more accurate evaluation, anterior (a) and lateral (d) planar static images were obtained for a duration of 5 min which showed accumulation in the same area (white arrows). The patient’s medical history revealed recurrent well-differentiated abdominal liposarcomas with a previous resection of a small bowel liposarcoma mass around 3 years ago, which included surgical margins and omental involvement. It is worth noting that several studies have reported unusual accumulation of renal radiotracers such as Tc-99m DTPA[2] and Tc-99m (V) DMSA[34] in extrarenal sites of various soft-tissue sarcoma types during renal scintigraphic examinations.[56] The uptake of these radiotracers has been linked to the histological subtype and tumor differentiation degree. Specifically, dedifferentiated liposarcoma has been found to exhibit a higher uptake of radiotracers compared to well-differentiated liposarcoma.[789] In the present case, nonuniform accumulation of Tc-99m EC in tumor sites, which has been confirmed by subsequent CT scan [Figure 2], may be related to the transformation of tumor tissue from well-differentiated to dedifferentiated type](/content/210/2024/39/3/img/IJNM-39-234-g001.png)
Figure 1
A 70-year-old male patient, with uncontrolled hypertension despite antihypertensive medications, underwent technetium-99m ethylene dicysteine (Tc-99m EC) scintigraphy before and after captopril administration to evaluate potential renovascular hypertension.[1] However, the assessment ruled out the suspected diagnosis. Interestingly, pre- and postcaptopril Tc-99m EC scanning disclosed accumulation of the radiotracer in the left perirenal space (c: black arrow and b: black arrowhead). A photopenic area, corresponding to heterogeneous uptake on posterior views (c: null arrow), was seen on the left side of the bladder on dynamic images. For more accurate evaluation, anterior (a) and lateral (d) planar static images were obtained for a duration of 5 min which showed accumulation in the same area (white arrows). The patient’s medical history revealed recurrent well-differentiated abdominal liposarcomas with a previous resection of a small bowel liposarcoma mass around 3 years ago, which included surgical margins and omental involvement. It is worth noting that several studies have reported unusual accumulation of renal radiotracers such as Tc-99m DTPA[2] and Tc-99m (V) DMSA[34] in extrarenal sites of various soft-tissue sarcoma types during renal scintigraphic examinations.[56] The uptake of these radiotracers has been linked to the histological subtype and tumor differentiation degree. Specifically, dedifferentiated liposarcoma has been found to exhibit a higher uptake of radiotracers compared to well-differentiated liposarcoma.[789] In the present case, nonuniform accumulation of Tc-99m EC in tumor sites, which has been confirmed by subsequent CT scan [Figure 2], may be related to the transformation of tumor tissue from well-differentiated to dedifferentiated type
![Following the unexpected findings of extrarenal radiotracer accumulation and concurrent ipsilateral nonobstructive hydroureteronephrosis [Figure 1], it was suggested that a noncontrast-enhanced CT scan is performed to pinpoint the exact anatomical location of these findings. One month after the Tc-99m EC study, a noncontrast-enhanced abdominal CT scan was performed. This procedure revealed the presence of two distinct masses. The first was a significant fat-containing mass located in the left section of the abdominal cavity, specifically in the pararenal space. This mass extended downward to the left iliac fossa, moving the descending colon leftward and infiltrating the left abdominal wall (a). The second soft-tissue mass was found in the left side of the pelvic cavity. It was exerting a compression effect on the urinary bladder causing it to deviate to the right (b)](/content/210/2024/39/3/img/IJNM-39-234-g002.png)
Figure 2
Following the unexpected findings of extrarenal radiotracer accumulation and concurrent ipsilateral nonobstructive hydroureteronephrosis [Figure 1], it was suggested that a noncontrast-enhanced CT scan is performed to pinpoint the exact anatomical location of these findings. One month after the Tc-99m EC study, a noncontrast-enhanced abdominal CT scan was performed. This procedure revealed the presence of two distinct masses. The first was a significant fat-containing mass located in the left section of the abdominal cavity, specifically in the pararenal space. This mass extended downward to the left iliac fossa, moving the descending colon leftward and infiltrating the left abdominal wall (a). The second soft-tissue mass was found in the left side of the pelvic cavity. It was exerting a compression effect on the urinary bladder causing it to deviate to the right (b)
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