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Abstract: A 47-year-old woman, a diagnosed case of syndrome of inappropriate secretion of antidiuretic hormone, underwent 18F-FDG PET/CT to detect occult malignancy for suspected paraneoplastic etiology. Abnormal FDG uptake was noted in the right lower chest region, which was correlated on corresponding CT images to be colonic activity interposed between the liver and elevated diaphragm, also known as Chilaiditi sign. Even though rare, Chilaiditi sign should be considered as a differential diagnosis of hypermetabolic activity in the right lower chest region on 18F-FDG PET/CT scan that is done to look for occult tumor as shown in this case., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2025 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 42-year-old man, a known case of FGF23-dependent hypophosphatemia, underwent 68 Ga- DOTATATE PET-CT, which showed a somatostatin receptor-expressing lesion in the left arch of foramen magnum that was correlated on MRI as a soft tissue lesion measuring 2.2 × 1.3 cm. It was excised and histopathologically confirmed as phosphaturic mesenchymal tumor. Postoperatively, patient improved clinically and recovered from hypophosphatemia completely. A distinct focal uptake in a 68 Ga- DOTATATE PET-CT in a patient with tumor-induced osteomalacia needs extensive workup and high degree of suspicion to rule out mesenchymal tumor at nonconventional location as seen in the present case., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 34-year-old woman who presented with severe psychosis and clinical features of Cushing syndrome underwent 18 F-FDG PET/CT that revealed hypermetabolic lung lesion along with predominantly increased metabolism of bilateral basal ganglia, a scintigraphic correlate of acute psychosis. The lesion was surgically excised and histopathologically proven to be adrenocorticotropic hormone-producing lung carcinoid. Posttreatment 18 F-FDG PET scan showed restoration of normal brain metabolism with complete reversal of psychosis. Even though rare, one should be aware of psychosis as an initial presentation of Cushing syndrome and use of 18 F-FDG PET/CT for mapping brain metabolism as shown in this case., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 53-year-old woman of primary hyperparathyroidism with both ultrasound neck examination and planar 99m Tc-MIBI scan being negative revealed a tracer-avid focus in the left submandibular region in early (15 minutes postinjection) 99m Tc-MIBI SPECT/CT views, raising a suspicion of rare ectopic parathyroid adenoma. This finding was correlated on 4D-CT and confirmed on histopathology following surgical excision. Submandibular region is an unusual location for ectopic parathyroid adenoma. Nevertheless, high degree of suspicion with utilization of multimodality imaging including 99m Tc MIBI-SPECT/CT and 4D-CT improves preoperative detection of parathyroid adenoma at rare ectopic sites as seen in this case of persistent hyperparathyroidism., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Differentiated thyroid carcinoma (DTC) usually manifests as an indolent cancer with good prognosis. However, rarely uncommon sites of metastatic involvement can worsen the prognosis and require aggressive therapeutic approach. Here in, we describe 5 patients (3 women and 2 men) harboring rare sites of metastatic involvement from DTC including the adrenals, colon, kidneys, urinary bladder, brachial plexus, and superior vena cava with contiguous right atrial involvement. The awareness of such rare sites of involvement from DTC is imperative for treating clinicians to plan individualistic approach in management including multiprong therapies for better patient care., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 34-year-old woman, who was 11 months postpartum, underwent 99mTc-MIBI myocardial perfusion SPECT imaging for atypical symptomatology with normal baseline electrocardiogram and 2-dimensional echocardiography. She was lactating on and off, preferentially from the right breast. Analysis of the raw images revealed unilateral intense tracer uptake in the right breast region that persisted in the delayed spot views (24-hour postinjection). Although bilateral breast uptake of 99mTc-MIBI may be seen in postpartum scenario, unilateral breast uptake can also occur in patients with preferential lactation from 1 breast as seen in this case and should not be mistaken for pathology., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 48-year-old man, a case of metastatic insulinoma, who failed transarterial chemoembolization of liver metastases underwent multiple cycles of peptide receptor radionuclide therapy with 177Lu-DOTATATE, following which a complete morphologic and metabolic response was demonstrated on 68Ga-DOTATATE PET/CT. Patient had a remarkable improvement in his quality of life as intractable hypoglycemic episodes resolved after treatment. Peptide receptor radionuclide therapy is a promising targeted radionuclide therapy in patients of metastatic insulinomas that can result in reduced tumor burden and improved quality of life, particularly those who fail the conventional treatment modalities as seen in the present case., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose of the Report: Prostate-specific membrane antigen (PSMA) is a member of superfamily of zinc-dependent exopeptidases that is robustly expressed in prostate cancer cells and nonprostatic solid tumor neovasculature including microvessels of thyroid tumors. Its expression in differentiated thyroid cancer (DTC) has been confirmed in many recent studies, but systematic studies exploring PSMA expression in patients with DTC with thyroglobulin elevation and negative iodine scintigraphy (TENIS) are lacking. The aim of the present study was to evaluate the role of PSMA scan in TENIS patients with DTC., Methods: Nine consecutive patients with DTC with proven TENIS syndrome (6 men and 3 women with age range 29-68 years and mean age of 48 years) underwent 18F-FDG PET/CT as per the institution protocol. Thereafter, they were subjected to 68Ga-PSMA-HBED-CC PET/CT as per the institution protocol within a week of FDG PET imaging. Prostate-specific membrane antigen expression (SUVmax) in the lesions was compared with 18F-FDG PET and CT scan findings., Results: In 5 of 9 patients with TENIS, the metastatic lesions showed PSMA expression. A total of 14 lesions were seen on the CT scan. Prostate-specific membrane antigen PET detected 9 of 14 lesions (64.28%) (SUVmax ranging from 10.1 to 45.67; median SUVmax of 16.31), whereas FDG PET was positive in 11 of 14 lesions (78.57%). The lesions that showed PSMA uptake was localized to bones (5 of 9) and lungs (4 of 9). Two lesions that were localized to iliac crest and acetabulum were missed on FDG PET but were seen on CT and PSMA PET scan., Conclusions: The results of this pilot study indicate that 68Ga-HBED-CC-PSMA PET/CT demonstrates PSMA expression in TENIS patients with lesions being localized to the bones and lungs. 68Ga-PSMA PET/CT could be useful for the identification of TENIS patients who might benefit from PSMA-targeted radionuclide therapy., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 43-year-old man diagnosed with fibrous dysplasia with McCune-Albright syndrome was subjected to 18F-fluoride bone scan and 68Ga-PSMA-HBED-CC PET/CT as per the institution protocol. 18F-bone scan revealed extensive involvement of axial and appendicular skeleton confirming polyostotic fibrous dysplasia. 68Ga-PSMA PET/CT showed increased tracer uptake in corresponding lesions of fibrous dysplasia. PSMA uptake in fibrous dysplasia lesions has been rarely described with literature evidence being limited to anecdotal case reports. Nevertheless, due to increasing use of PSMA PET/CT, one should be aware of this false-positive finding to avoid misinterpretation of the scans., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Poland syndrome is a rare congenital anomaly characterized by unilateral aplasia of the sternoclavicular head of pectoralis major muscle with varying degree of same side upper limb anomalies. A 44-year-old man, with a case of adenocarcinoma of stomach, whose CECT chest revealed complete absence of pectoralis major and minor muscles on the left side, was diagnosed with Poland syndrome without presence of typical ipsilateral limb anomalies. Follow-up PET/CT revealed metabolically active recurrent disease with typical findings of Poland syndrome. It is important to be aware of oncologic association in a patient of Poland syndrome as highlighted in the present case., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

A 4-day-old female neonate with raised cord blood thyroid-stimulating hormone (127 μIU/mL) underwent Tc thyroid scan to rule out thyroid dysgenesis. The images revealed midline focus of lingual thyroid as the only functioning thyroid tissue. In addition, bilateral focal and symmetrical breast uptake was seen without clinically palpable breast nodule on either side. Transplacental transfer of maternal hormones leading to stimulation of neonatal breasts explains this unusual scan finding. One should be aware of this rare pattern of focal breast uptake in Tc-pertechnetate scan in neonates with congenital hypothyroidism to avoid scan misinterpretation.

Purpose of the Report: Prostate-specific membrane antigen (PSMA) is a type II membrane glycoprotein, which is not only overexpressed in prostate cancers but also in variety of solid tumors including glioblastoma multiforme. The aim of the present study was to demonstrate PSMA expression in gliomas using Ga-PSMA-HBED-CC(PSMA 11) PET/CT., Patients and Methods: Ten patients with initially MRI suspected and eventually histopathologically proven gliomas [8 males (age range 30-73 yr; mean age 51.8 yr); 2 females aged 39 and 55 years] were subjected preoperatively to regional brain PET scan with Ga-PSMA-11 and F-FDG PET/CT. Final histopathology of brain lesions, their MIB-1 proliferation index (MIB-1 PI) were compared with PSMA and FDG PET findings., Results: FDG PET/CT showed distinct FDG uptake in high-grade gliomas, whereas low-grade gliomas were non-FDG-avid amidst physiological tracer uptake. In vivo PSMA expression was seen in all patients with glioma. Of these, the 7 patients of glioblastoma harboring 8 lesions showed significantly higher PSMA expression than those with low-grade gliomas, average SUVmax being 16.93 and 2.93, respectively. Similarly, average tumor-to-background ratios (13.95 and 3.42, respectively) and MIB-1 PI (17.31 and 3.3, respectively) were substantially more in high-grade versus low-grade gliomas., Conclusions: The results of this pilot study show that Ga-HBED-CC-PSMA PET/CT can be used to characterize the PSMA expression in gliomas, high-grade ones demonstrating higher SUVmax, MIB-1 PI tumor-to-background ratio than the low-grade ones. With these results as basis, certain patients may benefit from potential PSMA-targeted radionuclide therapy.

Purpose of the Report: Prostate-specific membrane antigen (PSMA) overexpression is not restricted to prostate cancer, but it has also been demonstrated in gliomas, lung cancer, and in tumor neovasculature. Systematic studies exploring PSMA uptake in thyroid tumors are lacking. The aim of this pilot study was to assess PSMA expression in patients with metastatic differentiated thyroid cancer (mDTC)., Materials and Methods: Ten patients of mDTC harboring 32 lesions (5 men; age range, 38-65 years; mean age, 50 years) underwent prospective evaluation with radioiodine (I), F-FDG PET, and Ga-PSMA-HBED-CC PET scans as per the institution protocol. PSMA expression (SUVmax) was compared with F-FDG and I scan findings in all patients., Results: Lesions were radioiodine avid in 8 patients, whereas 2 were classified as thyroglobulin elevation with negative iodide scintigraphy (TENIS) patients. All patients with iodine-avid metastatic disease showed substantial PSMA uptake. PSMA PET detected 30/32 total lesions (93.75%; SUVmax ranging from 4.86 to 101.81 with median SUVmax of 31.35), whereas FDG PET/CT was positive in 23/32 lesions (81.85%). Twenty-one (70%) of 30 lesions that showed PSMA expression were localized to the bones. PSMA localized a lesion in each of the 2 TENIS patients similar to FDG PET scan., Conclusions: Ga-PSMA-HBED-CC PET/CT is a potentially useful imaging modality in patients of mDTC with most (70%) of PSMA expressing metastasis being localized to the bones. PSMA PET/CT could be useful for identifying patients with limited therapeutic options (eg, TENIS) who might benefit from PSMA-targeted radionuclide therapy.

Posttherapy scan in a 21-year-old woman with papillary carcinoma of thyroid with lymph node metastasis, who received 5.55 GBq of radioiodine (I), revealed halo-like diffuse tracer uptake in the pericardial region. Echocardiography showed no abnormality except pericardial effusion, which subsided after reinstitution of levothyroxine therapy. Although rare, false-positive radioiodine uptake can occur in pericardial effusion secondary to thyroxine withdrawal-related hypothyroidism and needs close monitoring of the patient.

Paragangliomas (PGLs) due to succinate dehydrogenase subunit B (SDH-B) mutation can be aggressive. A 40-year-old woman with normetanephrine-secreting, extra-adrenal, abdominal PGL due to SDH-B genetic mutation underwent surgical excision of primary, followed by whole-body I-MIBG scan after 6 months, which showed no abnormality. However, Ga-DOTANOC and F-FDG PET/CT scans showed primary site recurrence, hepatic and skeletal metastasis, with latter scan revealing more lesions. We suggest that F-FDG PET should be done in all patients with PGL due to SDH-B mutations, as it may show additional unsuspected lesions that may be missed by other tracers.

A 37-year-old woman with clinical and biochemical features of ectopic adrenocorticotropic hormone (ACTH) syndrome underwent 68Ga DOTANOC PET/CT to localize the source of ectopic ACTH secretion. The images showed 35 × 45-mm retroperitoneal mass with significantly increased tracer uptake. Plasma-free metanephrines and serum chromogranin levels were normal. Whole-body 131I-MIBG scan including the retroperitoneal mass did not show any abnormal uptake. On excision, histopathology of this paravertebral abdominal mass revealed carcinoid tumor. We suggest the use of 68Ga DOTANOC PET/CT as a first-line imaging modality for localization of source of ACTH secretion in ectopic ACTH syndrome.

A 60-year-old woman with clinical and biochemical features suggestive of adrenal insufficiency was found to have bilateral adrenal masses on CT scan and was subjected to F-FDG PET scan. The scan showed hypermetabolic mediastinal nodes in addition to intense tracer uptake in bilateral adrenal masses. CT-guided adrenal biopsy grew Histoplasma capsulatum on Sabouraud dextrose agar culture. A second F-FDG PET scan after 6 months of appropriate antifungal therapy showed a significant decrease in intensity of uptake consistent with the clinical outcome.

A 43-year-old man with known superior mediastinal syndrome due to (99m)Tc HYNIC DOTA SPECT/CT and (18)F-FDG PET tracer avid inoperable metastatic carcinoid received peptide receptor based radionuclide therapy (PRRT) with (177)Lu-DOTATATE. Repeat evaluation at 3 months post-therapy demonstrated stable disease with alleviation of patient's symptoms and remarkable improvement in the quality of life. PRRT with (177)Lu-DOTATATE may be an option for inoperable mediastinal carcinoids with superior mediastinal syndrome.

A 48-year-old male patient of papillary carcinoma of thyroid, who had received 3.145 GBq of radioiodine ((131)I) 6 months earlier, presented with recurrent headaches and progressively worsening double vision for 2 weeks. Iodine avid and low metabolic parasellar mass was seen on (131)I SPECT/CT and (18)F-FDG PET/CT, respectively. In view of no bony erosion, meningioma or schwannoma rather than metastasis was considered as first differential diagnosis. However, final histopathology after its partial excision revealed metastasis from thyroid cancer. This case highlights the importance of radioiodine scan to detect a rare occurrence of parasellar metastasis from thyroid cancer.

We report a rare case of adrenal and renal metastases from papillary thyroid carcinoma (PTC). A 30-year-old man underwent total thyroidectomy with left neck dissection for cytology proven nodal metastases from PTC. This was followed by high-dose radioiodine therapy with a dose of 265 mCi (9.805 GBq). Thereafter, patient was lost to follow-up. He presented 2 decades later with low backache radiating to both the lower limbs. Magnetic resonance imaging examination of spine detected left SI joint, dorsal and lumbar vertebral metastases. A whole-body radioiodine scan showed extensive iodine avid foci in thyroid bed, mediastinum, bilateral lungs, liver, bones, and in bilateral lumbar regions. An abdominal single photon emission computed tomography-computed tomography (CT) revealed the lumbar lesions to be within bilateral adrenal glands. Contrast-enhanced CT of abdomen revealed lesions in bilateral adrenals and renal regions suggestive of metastases. A CT-guided biopsy of left adrenal focus confirmed metastasis from the carcinoma of thyroid. A high degree of suspicion with further radiologic and cytologic correlation clinched the diagnosis of both adrenal and renal metastases from PTC, which has been rarely reported. Fortunately, radioiodine concentration in adrenal metastases made them amenable to high-dose radioiodine therapy. Therefore, 225 mCi (8.325 GBq) of radioiodine was administered to this patient. This case is a strong reminder of the fact that regular and long-term follow-up is imperative in the management of thyroid cancer patients.

Background: During myocardial perfusion imaging with Tc-99m sestamibi, intestinal and hepatic radiotracer activity commonly interfere with visualization of the inferior wall of the myocardium leading to difficulties in interpretation. This study was undertaken to assess if carbonated lime drink ingestion prior to imaging prevents the said interference and improves the quality of images., Materials and Methods: The study group comprised 33 consecutive patients including 26 males (age range: 30-80 years) and 7 females (42-62 years) who were referred for myocardial perfusion imaging. Of 33 patients, 21 (18 males, 3 females) were imaged at rest, 5 patients (3 males, 2 females) underwent physical stress, and 7 patients (5 males, 2 females) had pharmacological stress with adenosine. Five to 10 minutes after intravenous injection of 296 to 444 MBq (8-12 mCi) Tc-99m MIBI, anterior, and left anterior oblique (LAO) 45 degree planar views were acquired with a gamma camera using LEHR collimator. Each view was acquired for 100 seconds in a 256 x 256 matrix in all patients. Thereafter each patient was administered about 250 mL of a carbonated lime drink and repeat views were acquired within 5 minutes with the same parameters. Quantitative assessment of counts in the inferior wall of myocardium (M) to those in adjacent abdomen (A) was performed on both pre- and postintervention studies by drawing an ROI of about 50 +/- 5 pixels. M/A ratios were recorded for each patient in both the groups. The student t test was performed to evaluate the significance of difference between pre- and postintervention images. P < 0.05 was considered significant. All patients underwent myocardial perfusion single photon emission computed tomography., Results: It was found that the inferior wall of the myocardium was better visualized, and there was no interference from gut or hepatic tracer activity in postintervention planar and single photon emission computed tomography reconstructed views as compared with preintervention images in all patients. The M/A ratio expressed as mean +/- SD was significantly higher in the postintervention group, viz. 2.19 +/- 0.71 in the anterior and 2.07 +/- 0.70 in the LAO45 views as compared with those of preintervention values of 1.50 +/- 0.59 in the anterior and 1.41 +/- 0.49 in the LAO 45 views, respectively (P < 0.001)., Conclusion: We conclude that intake of carbonated lime drink is a simple and an effective technique to improve the image quality of the inferior wall of the myocardium on myocardial perfusion imaging with Tc-99m MIBI. This technique may also help in reducing the time interval between injection of radiotracer and imaging, which is otherwise delayed in routine practice.

A 7-month-old male infant who presented with bleeding per rectum was evaluated and diagnosed to have ileocolic intussusception on ultrasonography. Despite ultrasonography-guided saline reduction, there was persistence of bleeding per rectum. He was given blood transfusion and referred for Tc-99m pertechnetate scan to rule out ectopic gastric mucosa. The scan was done as per the standard institution protocol and the images revealed a focus of progressively increasing tracer uptake in the right lower abdominal quadrant suggesting the presence of ectopic gastric mucosa. An exploratory laparotomy revealed ileocolic intussusception secondary to Meckel diverticulum acting as a pathologic lead point (PLP). A wedge resection of the intestinal wall containing the diverticulum with suture closure was performed. The presence of Meckel diverticulum and ectopic gastric mucosa was confirmed on subsequent histopathological examination of the specimen. The patient rapidly improved postoperatively and was discharged 9 days after surgery. Bleeding per rectum can be seen in both intussusception and in Meckel diverticulum with ectopic gastric mucosa. Intussusception originating from a Meckel diverticulum as PLP remains a diagnostic challenge because of the overlapping symptoms.The Meckel scan findings, in this case, avoided the further CT scan, angiography, and endoscopy for the diagnosis of the cause of symptoms, sparing not only the time but cost of investigations and unnecessary radiation exposure to the patient.

A 52-year-old man with follicular thyroid carcinoma was administered 182 mCi of radioiodine (I-131) a month after total thyroidectomy. Post-therapy scan revealed diffuse uptake of radioiodine in the apical left lung. CT-guided biopsy of this mass revealed mucinous bronchoalveolar carcinoma. Immunohistochemistry for thyroglobulin was negative. An FDG PET scan showed avid uptake in the lung mass. Surgery was ruled out, so he was given chemotherapy, without benefit. The lesion continued to show I-131 uptake even while on daily T3 substitution, suggesting that the mass was thyroid stimulating hormone-independent. Because the mass showed I-131 uptake and chemotherapy was not beneficial, it was decided to treat with I-131. He was continued on T3 substitution therapy and was given 209 mCi of I-131. Follow-up CT scan a few weeks later reported a 1-cm all round reduction of the mass. I-131 scan showed avid tracer uptake in the mass. This case suggests the possibility of this therapeutic option in nonthyroidal tumors that may concentrate radioiodine.

Malignant tumors of the breast have an inherent potential to metastasize more often to the regional lymph nodes. It is rare to find a metastasis to the oral region from a primary in the breast, but when this does occur, it usually involves the jawbones rather than the soft tissues. A 33-year-old premenopausal woman, a diagnosed case of locally advanced right breast carcinoma, underwent right modified radical mastectomy followed by chemotherapy as per the institutional protocol. She presented after 2 years with an exophytic growth in the upper alveolar region of the oral cavity. Biopsy indicated gingival metastasis from a poorly differentiated adenocarcinoma of the breast. She was referred for F-18 FDG PET scan to evaluate the disease status before planning radiotherapy to the gingival metastasis. F-18 FDG PET scan was done after intravenous injection of 370 MBq (10 mCi) of tracer. Whole-body PET images were reconstructed in iterative algorithm (OSEM). Whole-body F-18 FDG PET scan showed hypermetabolic foci in the midmaxillary region (SUV max: 6.5), upper end of the right humerus, a large hypermetabolic area in the upper zone of the right lung with contiguous hilar node involvement on the right side of the lung, and an area of intense hypermetabolic activity in the left acetabular and ischial region. The present case demonstrates a rare site of metastasis in the oral region from carcinoma of the breast.