Main Article Content
Abstract
Background: Carcinoma of unknown primary (CUP) is a challenging clinical diagnosis, representing histologically confirmed metastatic cancer where the primary tumor site remains unidentified after a standard diagnostic workup. While 18F-FDG PET/CT is recommended by current guidelines, its accessibility is limited in many regions. This report explores the diagnostic utility of Technetium-99m (99mTc)-Sestamibi Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) as a valuable alternative.
Case presentation: A 67-year-old female presented with musculoskeletal pain. A biopsy of a right ulnar lesion confirmed metastatic carcinoma. Immunohistochemistry (IHC) suggested a possible primary from the lung, breast, or upper gastrointestinal tract. Due to the unavailability of 18F-FDG PET/CT, a 99mTc-Sestamibi whole-body scan with SPECT/CT was performed. The scan identified a metabolically active, malignant-appearing nodule in segment 6 of the left lung and confirmed widespread skeletal metastases. Although a lung biopsy was not feasible due to limited access, the patient was treated with a lung cancer protocol. This resulted in significant clinical improvement.
Conclusion: 99mTc-Sestamibi SPECT/CT served as a critical diagnostic tool in this case of CUP. It successfully identified a suspected pulmonary primary, enabling targeted therapy and leading to a positive clinical outcome. This case highlights the modality's efficacy as a tumor-seeking agent and underscores its essential role in the diagnostic armamentarium for CUP, particularly in resource-limited healthcare settings.
Keywords
Article Details
As our aim is to disseminate original research article, hence the publishing right is a necessary one. The publishing right is needed in order to reach the agreement between the author and publisher. As the journal is fully open access, the authors will sign an exclusive license agreement.
The authors have the right to:
- Share their article in the same ways permitted to third parties under the relevant user license.
- Retain copyright, patent, trademark and other intellectual property rights including research data.
- Proper attribution and credit for the published work.
For the open access article, the publisher is granted to the following right.
- The non-exclusive right to publish the article and grant right to others.
- For the published article, the publisher applied for the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.