Primary squamous cell carcinoma (SCC) of the trachea is rare. Here, we presented a rare case of primary SCC of the trachea arising 4 years after radioiodine (RAI) treatment of papillary carcinoma of the thyroid. In this case, concomitant uptake of I-RAI and F-FDG was demonstrated in the thyroidal mass with tracheal invasion, which mimicked mixed well-differentiated and dedifferentiated thyroid carcinoma. The diagnosis of SCC of the trachea was made only after tracheal biopsy. This case illustrates that FDG-avid thyroid bed lesion, in the presence of thyroid carcinoma, may not necessarily be related to the thyroid pathology.
A 17-year-old adolescent boy with biochemically raised 2-hour urinary metanephrine and normetanephrine as well as CT findings of retroperitoneal soft tissue mass and bony metastases was referred for further assessment. Apart from Ga DOTATATE PET/CT evaluation, pretargeted systemic radionuclide therapy assessment with I-MIBG scintigraphy showed unusual phenomenon of MIBG superscan. Postsurgically, restaging Tc-MDP bone scintigraphy showed typical bone superscan features. The MIBG superscan was better delineated on post-I-MIBG therapy images.
Extramammary Paget's disease (EMPD) is a rare disease with an estimated prevalence of 0.1 to 2.4 per 1,000,000 person-years. Metastatic EMPD has a poor prognosis with a 5-year survival of approximately 7%. Local therapy is the only curative option with surgery being recommended for resectable disease. It is therefore crucial to be able to stage such patients appropriately. The utility of F-FDG PET/CT for this disease is not well established. We share a case on how F-FDG PET/CT was used to stage metastatic EMPD.
Recent case reports and series have demonstrated the usefulness of Ga/F-PSMA PET/CT in restaging recurrent renal cancer after nephrectomy. We presented a case of a patient with renal mass who had undergone both F-FDG and Ga-PSMA PET/CT for diagnosis and staging. Concordant tracer uptake in the primary tumor and metastatic lesions was demonstrated by both radiotracers. Final histopathological reports revealed clear cell renal cell carcinoma. Furthermore, unusual left metacarpal bone metastasis was also detected.
Endometrial cancer, a common cancer affecting women, has the tendency to metastasize to the lung and liver. Bone metastases in endometrial cancers are rare and accounts for less than 1% of the overall incidence of metastases. We report a case of a 30-year-old single nulliparous woman with metastatic recurrence of endometrioid adenocarcinoma of the endometrium involving the pelvic bone, and the role of bone scintigraphy in detection and staging of the disease.
A 47-year-old man with newly diagnosed nasopharyngeal carcinoma underwent staging F-FDG PET/CT. Apart from showing increased FDG uptake in the primary site and locoregional nodal and liver metastases, an unusual site of intense FDG focus was demonstrated in the left adrenal gland. He underwent CT-guided biopsy, and the histopathologic diagnosis was benign fibrous histiocytoma.
Nonosseous uptake in Tc-hydroxymethylene bone scintigraphy should always be evaluated for any possibility of pathological changes. We share interesting images of a 60-year-old woman initially investigated for suspected osteomyelitis of the left femur but found to have an extraosseous uptake in the right hemithorax on bone scintigraphy. Plain chest radiograph followed by contrast-enhanced CT of the thorax revealed the presence of a lung mass in the right lower lobe with no lymphadenopathy. CT-guided biopsy yielded fibrocollagenous tissue, partly lined by benign pneumocytes. The F-FDG-avid lung mass was confirmed to be sclerosing pneumocytoma postlobectomy.
Urothelial carcinoma is the fourth most common genitourinary tumor with the majority of the tumor involving the urinary bladder. Only 5% involves the renal pelvis and ureter. Metastatic urothelial carcinoma of the renal pelvis frequently involves the lymph nodes, lung, liver, bone, and peritoneum. We share rare interesting F-FDG PET/CT images of a 60-year-old man with metastatic urothelial carcinoma of the renal pelvis to the bowel.
We report a case of a 33-year-old woman who underwent stress and rest myocardial perfusion scintigraphy (MPS) to exclude coronary artery disease. MPS images showed an apparent dextrocardia with a right-sided septal wall uptake. The electrocardiograph showed a right axis deviation with dominant R waves at leads aVR and V1. Upon retrieval of the patient's medical records, she had an underlying transposition of great arteries and underwent a Senning atrial switch surgery. Hence, the MPS images demonstrated a prominent right ventricular wall due to its function as the "systemic" ventricle with minimal uptake in the "pulmonary" left ventricle.
A 57-year-old woman was referred for radioactive iodine therapy 12 weeks after completion thyroidectomy and left modified radical neck dissection for pT2N1Mx follicular variant papillary thyroid carcinoma. After 4 weeks of l-thyroxine withdrawal, stimulated serum thyroglobulin level was less than 0.1 ng/mL with positive thyroglobulin antibody. Posttherapy 131I scintigraphy with SPECT/CT of the head and abdominopelvic region showed thyroid residual in the neck, occipital bone metastasis, and heterogenous tracer uptake in a large peritoneal mass, likely arising from the left ovary. Left salpingo-oophorectomy was performed, and histopathologic examination revealed endometrioid carcinoma of left ovary.
18F-FDG PET/CT has been found useful for the detection of the source of infection/inflammation in the body. Platelet-rich plasma is a new treatment modality in which plasma is injected subdermally or intradermally for potential hair regrowth into the scalp. We report a case of 43-year-old woman with right breast cancer who underwent surgery, chemotherapy, and radiotherapy 2 years ago and is currently on hormonal therapy. 18F-FDG PET/CT demonstrate incidental findings of increased FDG avidity in the scalp after platelet-rich plasma therapy.
A 46-year-old man with end-stage renal disease and renal cell carcinoma underwent F-FDG PET/CT for initial staging followed by F-PSMA-1007 PET/CT. Unlike F-FDG, which undergoes renal clearance, F-PSMA-1007 undergoes hepatobiliary clearance and thus generates superior quality images. F-PSMA-1007 PET/CT showed intense tracer-avid left renal mass lesion (FDG nonavid); lytic bone lesions (FDG avid) and single liver lesion (FDG nonavid). This case highlights the superiority of F-PSMA-1007 over F-FDG PET/CT in identifying primary lesion as well as metastatic sites in case of renal cell carcinoma even in the presence of end-stage renal disease.
Severe COVID-19 infection is associated with significant coagulopathy. We would like share a case of an asymptomatic 26-year-old man who tested positive for COVID-19 and had elevated d-dimer levels. Because of inconclusive CTPA findings, V/Q (ventilation/perfusion) SPECT/CT was performed, which confirmed the presence of pulmonary embolism. This case highlights the fact that pulmonary embolism should not be overlooked in a COVID-19 patient who has raised d-dimer levels, even in the absence of symptoms. It also highlights the importance of performing a V/Q study when CTPA results are inconclusive or when there are contraindications for iodinated contrast media.
We report a case of a 56-year-old woman who underwent Tc-DTPA renal scintigraphy for the evaluation of a right pelviureteric junction calculi, which incidentally showed radiotracer uptake in a giant liver hemangioma. The initial scintigraphic images showed a large lobulated lesion with peripheral uptake of radiotracer at the right abdominal region, resembling a large hydronephrotic kidney. However, the pattern of progression of the radiotracer, coupled with the clinical history and available corresponding radiologic images, confirmed the uptake to be that of a giant liver hemangioma.
A 57-year-old woman received radioiodine therapy post total thyroidectomy for pT3aNxMx follicular thyroid carcinoma. Posttherapy 131I whole-body scan showed 131I concentration in the chest, mediastinum, and left upper thigh with stimulated thyroglobulin (Tg) of 89 μg/L. Subsequent radioiodine therapies showed persistent 131I accumulation in the anterior mediastinal soft tissue lesions and a hypodense segment VII liver lesion visualized on SPECT/CT, suggestive of iodine-avid metastatic disease despite the undetectable serum Tg (<1.0 μg/L) with no Tg antibody interference. Biopsy of the liver lesion revealed liver cyst, and consequent removal of the mediastinal lesions showed benign thymic cysts.
Superscan on PET/CT has been reported in the literature and mainly involved metastatic diseases. We report an uncommon case of a metabolic superscan on 18 F-FDG PET/CT in a 56-year-old man with end-stage renal disease on hemodialysis who presented with secondary hyperparathyroidism. Parathyroid scintigraphy showed 2 lesions posteroinferior to both thyroid lobes, suggestive of parathyroid adenoma/hyperplasia. FDG PET/CT performed to assess for pulmonary nodules revealed diffuse FDG hypermetabolism involving the visualized skull, mandible, spine, sternum, ribs, and appendicular skeleton without corresponding CT lesion with no urinary radiotracer excretion, consistent with metabolic superscan secondary to renal osteodystrophy.