Retrospective Diagnosis of Ca Thyroid on Thyroid Pertechnetate Scan -A part of Routine Post Thyroidectomy Work up For Nontoxic Multi Nodular Goiter.

Unsuspected thyroid cancer can be detected in multinodular goiter (MNG) where the risk of malignancy is 7-9%. Fine needle aspiration (FNAc) is performed in case of suspicious findings on ultrasound. With benign FNAC results there is no need for surgery unless the patient has pressure symptoms or cosmetic concerns, but the risk of overlooked malignancy is always present. We present the case of a patient with unexpected detection of papillary thyroid cancer on thyroid scan.

Rapidly growing massive abdominal sarcomatoid carcinoma on F18-FDG PET-CT scan.

Sarcomatoid carcinoma is a rare type of tumour and most commonly arises in the lungs. However, rarely can it also be found in the abdomen. Sarcomatoid tumours are aggressive with large tumoural volume showing cancerous epithelial cells mixed with sarcomatous (nerve, muscle, fat etc.) features on histopathology. Most of the carcinosarcomas arise in the background of pleomorphic adenoma, originating from a myoepithelial precursor. These tumours are resistant to treatment and rapidly metastasize. We present a unique case of hepatocellular sarcomatoid sarcoma, evaluated through F18-FDG PET/CT.

Clinical Significance Of Dermal Backflow On Lymphoscintigraphy In Patients With Lower Limb Edema.

Chronic blockage of the lymphatic system due to functional or anatomical causes results in lymphoedema which results in swelling due to accumulation of lymphatic fluid in the soft tissue. Lymphoedema commonly affects the upper and lower limbs but may be seen in the neck, chest wall, abdomen and genitalia. Lymphoscintigraphy is non-invasive and maps the lymphatic channels thereby indicating location of blockage along the lymphatic pathways. Blockage of lymphatic channels may lead to back pressure resulting in dermal backflow. We present a case of dermal backflow in bilateral lymphoedema.

Hepatic Haemangioma: A Diagnostic Dilemma With An Easy Solution.

Hepatic Haemangioma is the most common benign liver tumour. There are two types of haemangiomas: capillary haemangioma and cavernous haemangiomas. The term"giant haemangioma"isreserved for lesionslarger than 5 cm. Given the abundance of vascular structures around the liver, SPECT/CT hybrid imaging with 99mTc labelled Red Blood Cells (RBCs) constitutes an excellent modality for localization and characterization of hepatic haemangiomas.

Spectrum of technetium-99m methylene diphosphonate (99mTc MDP) uptake in Osteosarcoma.

Osteosarcoma is a frequently occurring primary skeletal malignancy in the adolescent population. It arises from primitive mesenchymal bone forming cells and frequently involves long bones near the metaphyseal growth plate. Multiple imaging modalities are used for complete staging workup at the time of presentation; including magnetic resonance imaging (MRI) for local disease extent, computed tomography (CT) scan to rule out pulmonary metastasis, and bone scan to look for distant osseous metastases. We present the case of a young boy with osteosarcoma of left tibia, showing additional findings on MDP bone scan acquired for initial staging work up.

I-131 Avid Tumor Thrombus in a Case of Poorly Differentiated Thyroid Cancer.

Intravenous tumor extension is a well-recognized phenomenon occurring in various malignancies but is a relatively rare entity in thyroid carcinoma. In patients with poorly differentiated thyroid cancer (pDTC), I-131 avid superior vena cava tumor (SVC) thrombus at initial presentation is infrequent and potential life threatening. Tumor thrombus can form either due to direct vascular extension of the primary mass or by hematogenous spread. Hybrid nuclear imaging can differentiate the two entities, which can impact the treatment plan of the patient. We present images of an interesting case of evolution of SVC thrombus in a 46-year-old woman with diagnosed pDTC over the span of two years.

18F-FDG PET-CT in Cutaneous Metastases in Breast Carcinoma: An unusual presentation.

Cutaneous and subcutaneous metastases are an exceedingly rare presentation in various malignancies. These represent poor prognosis and disease progression. Early detection of such findings helps in changing the management plan. 18F-FDG PET-CT has played a key role in deciding treatment plan for patients with breast cancer, by detecting metastatic sites, with a high sensitivity in detecting cutaneous metastases as seen in the following case.

Routine Use of Lateral Vertebral Assessment With DXA Scan for Detection of Silent But Debilitating Vertebral Fractures.

PURPOSE OF THE REPORT: Reduced bone mineral density is a major public health dilemma with high prevalence. Vertebral fracture (VF) is an independent risk factor for fragility fracture. Lateral vertebral assessment (LVA) in dual-energy x-ray absorptiometry is a reliable, low-radiation, accurate, and cost-effective method for VF assessment. PATIENTS AND METHODS: Five hundred seventy-five scans of oncologic and nononcologic patients were retrospectively reviewed irrespective of age or sex. Patients' symptoms, bone mineral density, and risk factors were also evaluated. Scans in which LVA was not acquired or had previously known VFs were excluded. RESULTS: The mean age of patients was 66 ± 11.5 years. Eleven percent of patients had VFs on LVA, of which 7 were excluded due to known VFs. Ten percent had new VFs, most of whom were women (n = 42). The most common risk factor was secondary osteoporosis in women and rheumatoid arthritis in men. Sixty-eight percent of the patients had solitary fractures, whereas 32% had multiple fractures. Most of these patients had underlying osteopenia (n = 19). FRAX was calculated twice: once with the history of personal fracture marked and the other time unmarked as these would not have been discovered if LVA was not acquired. Statistically significant mean percent difference of 5.4% was found in probability of major osteoporotic fracture and 2.1% in the mean risk of hip fracture. CONCLUSIONS: In our population, 10% patients had unsuspected VFs on LVA in dual-energy x-ray absorptiometry scan. Most of these were nononcologic patients with associated risk factors. Based on the FRAX tool, there is a significant difference in the 10-year risk of fracture when unsuspected fractures discovered on LVA are marked.

Superscan on 18F-FDG PET-CT imaging for lymphoma: How frequent is it?

This retrospective study was conducted to evaluate the frequency of PET superscan in baseline staging scans of lymphoma patients.The study was conducted at the Shaukat Khanum Memorial Cancer Hospital, Lahore, from October 1, 2018 to August 31, 2019. A retrospective review of baseline PET-CT scans of 203 lymphoma patients, performed during the period of October 1, 2017 to August31,2018, was done from the institutional database. Out of these 203 patients, PET superscan pattern was observed in 13 (6.4%) patients, 08 (61.5%) males and 05 (38.5%) females. Eight (61.5%) patients had Non-Hodgkin's lymphoma, while 05 (38.5%)had Hodgkin's lymphoma. Based on TNM staging 10 (76.9%) patients had stage IV disease, 01 (07.6%) had stage III disease, and 2 (15.4%) had stage II disease. PET-CT superscan pattern is uncommon and is not dependent on the stage of the disease. It should be recognised in clinical practice as it suggests a poor prognosis.

18F FDG PET-CT Super scan: Paediatric Rhabdomyosarcoma.

Rhabdomyosarcoma (RMS) is the most common paediatric soft-tissue sarcoma, making 50% of all diagnosed cases. It is a complex disease that has the potential to arise from any tissue of the body except the bones. There are four types of rhabdomyosarcoma; embryonal, botryoidal, alveolar and pleomorphic. [18F]-FDG PET-CT plays a vital role in staging, response evaluation and follow-up of the disease. Due to significant morbidity and mortality with high-risk disease, proper staging is of paramount importance.  Staging of rhabdomyosarcoma depends on tumour localization, infiltration of local structures by the primary tumour, nodal involvement, and presence of visceral metastases. Without timely intervention, rhabdomyosarcoma progresses at an exponential speed.

Diffuse hepatic uptake on bone scan in a terminally ill osteosarcoma patient.

Tc-99m methylene diphosphonate (MDP) bone scan is an effective tool for the evaluation of benign and malignant skeletal disorders. Hepatic uptake on bone scan is an unexpected finding and whenever present, the cause must be determined as the distinction between technical and pathological causes is important to direct further patient management. Identification of these abnormalities will decrease errors and provide cardinal clinical information. We present the image of a patient with Osteosarcoma of the left femur; who underwent bone scan for metastatic workup which showed diffuse hepatic uptake.

Short Latency Radiation Induced Osteosarcoma Detected on 18F-FDG PET/CT Scan in Solitary Plasmacytoma.

18Fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) plays a pivotal role in the staging, restaging, and surveillance of various bone tumors, including plasmacytomas and osteosarcomas. Solitary plasmacytomas most frequently occur in the bones and are primarily treated with either surgery or radiotherapy. Radiation-induced osteosarcomas (RIOS) usually develop after a median interval of 11 years between radiation and sarcoma presentation. However, these can rarely present with a short latent period of 4 years or even lesser. In such cases, whole-body imaging plays a vital role in the early detection and management of RIOS. Herein, we present the case of a 29-year-old female patient with solitary plasmacytoma undergoing a follow-up whole-body 18F-FDG PET/CT, which revealed metastatic RIOS after a short latent period.

Incidental Detection of Second Primary in Bladder on PET scan of a Patient with Colon Adenocarcinoma.

18F-FGD PET-CT scan has a well-established role in staging and restaging gastrointestinal tract carcinomas and less commonly for bladder malignancies. FDG detects tumours by the presence of increased metabolic activity in tumour cells showing as foci of increased uptake on the scan. Bladder malignancy is often masked by physiological excretion of radiotracer into the urinary bladder. Fortunately, fused CT images help in lesion detection. We present the case of a 45-year-old male with adenocarcinoma of the colon, referred for staging PET-CT. The scan showed a hypermetabolic lesion in the bladder which was later diagnosed as urothelial carcinoma.

Differentiated Thyroid Carcinoma: Distant Metastasis as an Unusual Sole Initial Manifestation.

OBJECTIVE: The objective of this study was to identify the characteristic features of patients with distant metastasis as the only manifestation of well-differentiated thyroid cancers and to analyze the treatment outcomes. METHODS: A retrospective review of all patients with well-differentiated thyroid cancers and distant metastasis as the sole initial presentation was carried out. Data regarding age, gender, tumor histology, site, symptoms, and treatment outcomes were collected. RESULTS: There were 10 patients who presented with distant metastasis as the only presentation. The mean age was 56.1 years. Eight (80%) patients had osseous metastasis, one (10%) had pulmonary and one (10%) had both. Follicular thyroid carcinoma was more common and seen in six (60%) patients. Seven (77.8%) out of nine patients had demised within five years of initial presentation. CONCLUSION: Distant metastases without a neck lump as the initial presentation of well-differentiated thyroid cancers are extremely rare. No specific guidelines are available to manage such patients due to lack of relevant data in the literature.

Bleomycin Toxicity - Findings on FDG PET CT.

Bleomycin, an antitumour antibiotic, is an essential part of treatment for multiple curable cancers, most commonly Hodgkin Lymphoma (HL) and germ cell tumours. Major limitation of its use is lung toxicity. Early diagnosis and treatment of bleomycin lung toxicity (BLT) is crucial, as the changes are reversible during early inflammatory phase only. 18F Flourodeoxyglucose (FDG) PET-CT can predict BLT early in the course of illness. It is important to pay attention to lung parenchymal uptake on interim and end of treatment scans, as this may predict lung toxicity even in the absence of morphological lung abnormalities and clinical symptoms.

"Superscan" on F18­fluorodeoxyglucose Positron Emission Tomography - Computed Tomography [18­F] FDG PET-CT.

"Superscan" features have been described in 18F FDG PET-CT (F18 fluorodeoxyglucose Positron Emission Tomography­Computed Tomography) scan; characterized by significantly increased uptake in one or more organ systems resulting in absent or decreased uptake in the organs which normally show physiological uptake. The importance of the awareness has evolved over the years in order to avoid false interpretation of scan findings as well as in determination of a high tumour burden. We present images of three patients who underwent 18F FDG PET-CT scan showing findings consistent with FDG PET-CT superscan.

Lymphoma involving the brain and adrenals: A chicken and egg situation.

Primary cerebellar diffuse large B-cell lymphoma (DLBCL) is a rare entity, which manifests with neurological symptoms. It is aggressive in nature with high rate of recurrence and short survival period. It commonly presents with local invasion and rarely spreads outside the central nervous system. Chemotherapy with radiation is the preferred treatment; however, surgery can be done for solitary lesions. Likewise, adrenal lymphoma as primary site of disease is rare but can present as extra-nodal disease. We present an unusual case of cerebellar DLBCL with bilateral adrenal involvement detected incidentally on 18-Fluorodeoxyglucose positron emission tomography (18F FDG PET-CT) scan.