Rev Esp Med Nucl Imagen Mol. 2015;34(1):60–61

Interesting image

Gastrointestinal stromal tumour with unusual sites of metastasis: Accurate staging with 18 F-FDG PET/CT Tumor del estroma gastrointestinal con metástasis en localización poco habitual:: una estadificación correcta con 18 F-FDG PET/TC Anirban Mukherjee, Sellam Karunanithi, Suhas Singla, Chandrasekhar Bal, Rakesh Kumar ∗ Department of Nuclear Medicine, All India Institute of Medical Sciences, New Delhi, India

a r t i c l e

i n f o

Article history: Received 7 January 2014 Accepted 3 February 2014 Available online 26 September 2014

A 57-year-old male presented with pain in the abdomen for which he underwent contrast-enhanced computed tomography (CECT), which revealed a large heterogeneously enhancing abdominal mass with multiple peritoneal, hepatic, adrenal and

A

pulmonary metastases (images not shown). Subsequent biopsy from the liver lesion revealed presence of spindle cells with immunohistochemistry positive for CD 117 and diagnosis of metastatic gastrointestinal stromal tumour (GIST) was made. 18 F

B

E

C

F

D

G

Fig. 1. 18 F-FDG PET/CT images revealing marginated abdomino-pelvic soft tissue density mass displacing the bowel loops and infiltration of the mesentry with heterogeneously increased tracer uptake (A and F; arrow). Additionally, there was evidence of metabolically active metastatic disease involving bilateral lungs (B), multiple skeletal muscles (C), multiple subcutaneous nodules (C), liver (D; arrow head), right adrenal (D), mesenteric nodules (E) and bone marrow sites (G).

∗ Corresponding author. E-mail addresses: [email protected], [email protected] (R. Kumar). 2253-654X/$ – see front matter © 2014 Elsevier España, S.L.U. and SEMNIM. All rights reserved. http://dx.doi.org/10.1016/j.remn.2014.02.002

A. Mukherjee et al. / Rev Esp Med Nucl Imagen Mol. 2015;34(1):60–61

fluorodeoxyglucose (18 F-FDG) PET/CT was performed for staging the disease and as a baseline study prior to treatment. PET/CT images revealed fairly marginated abdomino-pelvic soft tissue density mass displacing the bowel loops and infiltration of the mesentry with heterogeneously increased tracer uptake. Additionally, there was evidence of metabolically active metastatic disease involving right adrenal, multiple skeletal muscles, multiple bone marrow sites, bilateral lungs and liver (Fig. 1). Multiple FDG avid mesenteric and peritoneal nodules were also noted. GISTs are the most common mesenchymal neoplasm of the gastro-intestinal tract and are characterised by uncontrolled proliferation of interstitial cells of Cajal (ICC). Stomach is the most common site (70%) for GISTs followed by the small intestine (20%). Anorectal, colonic, and esophageal GISTs are uncommon, whereas extraintestinal GISTs are extremely rare. 18 F-FDG PET/CT has a higher sensitivity and accuracy for detecting marrow infiltration and/or metastases in comparison to CECT. In the present case, there was no significant cortical destruction or skeletal changes discernible on CT images involving the metabolically active marrow lesions. Distant metastases of GIST are reported in up to 50% of cases at presentation. Hematogenous spread and direct peritoneal seeding are the 2 main routes of metastasis, rendering the liver and peritoneum the most common locations. Distant metastasis to other sites, especially the bones and the lung, is relatively rare.1 18 F-FDG PET/CT appears to be of potential value in initial disease evaluation including

61

prediction of malignant potential in recently diagnosed GIST and in selection of optimal dose of imatinib for therapy.2 Though there are isolated reports citing the example of skeletal muscle metastases and adrenal metastases in the patients of GIST detected by conventional imaging,2 to our best of knowledge no such reports have been documented with 18 F-FDG PET/CT. Metastatic lesions in skeleton and lymph node have been documented on 18 F-FDG PET/CT.3 Furthermore the skeletal muscle and bone metastases in the present case were identified by the 18 F-FDG PET/CT demonstrating its potential advantage over CECT in the determination of initial staging and disease extent in the patients of GIST. This case was a unique case of GIST showing unusual site of metastasis identified on 18 F-FDG PET/CT and further emphasising the role of 18 F-FDG PET/CT in the initial evaluation of the patient with GIST. References 1. DeMatteo RP, Lewis JJ, Leung D, Mudan SS, Woodruff JM, Brennan MF. Two hundred gastrointestinal stromal tumors: recurrence patterns and prognostic factors for survival. Ann Surg. 2000;231:51–8. 2. Bashir U, Qureshi A, Khan HA, Uddin N. Gastrointestinal stromal tumor with skeletal muscle, adrenal and cardiac metastases: an unusual occurrence. Indian J Pathol Microbiol. 2011;54:362–4. 3. Wong CS, Chu YC, Khong PL. Unusual features of gastrointestinal stromal tumor on PET/CT and CT imaging. Clin Nucl Med. 2011;36:e1–7.

CT.

CT. - PDF Download Free
735KB Sizes 0 Downloads 13 Views