Insight into paraneoplastic vasculitis associated with adenocarcinoma colon on F18-FDG PET-CT.

Paraneoplastic vasculitis is a rare entity usually seen in haematological malignancies. Its incidence is even more rare in solid tumours like breast, renal, colon and lung. F-18 FDG PET-CT is commonly used to differentiate between active vasculitis and atherosclerosis in patients with large to medium vessel vasculitis. We present a case of moderately differentiated adenocarcinoma colon presenting for the assessment of with paraneoplastic vasculitis.

Hepatic Visualization on DXA Scan: An Ancilliary Finding.

Thalassemia major is a genetic haemoglobinopathy manifesting as severe anaemia, jaundice and hepatosplenomegaly. Due to altered iron metabolism and increased bone resorption it is associated with secondary osteoporosis manifested as decreased bone mineral density (BMD). Dual energy X-ray absorptiometry (DXA) is frequently performed for the diagnosis of secondary osteoporosis. Soft tissues are rarely visualized on DXA unless there is calcification involving those structures like nephro-, cholelithiasis or iatrogenic e.g. surgical clips. Hepatic iron deposition occurs in thalassemia due to repeated blood transfusions which leads to increased density of the liver resulting in visualization of liver on DXA scan. We present an interesting image of hepatic visualization on DXA performed for bone mineral density assessment in a patient with thalassemia major.

Solitary Osseous Metastasis of Hepatocellular Carcinoma on SPECT/CT.

Hepatocellular carcinoma (HCC), sixth most common cancer world-over, commonly metastasizes to lung, lymph nodes and adrenal glands. Incidence of osseous metastases in HCC has been reported to be 3-20 % which occurs predominantly in the axial skeleton. It only rarely occurs in the appendicular skeleton and that too as the solitary focus of metastatic deposit.3,4 We present a case of HCC with solitary osseous metastases to the proximal tibia.

Incidental finding of Psuedomyxoma Peritonei in Malignant Peripheral Nerve Sheath Tumour.

Psuedomyxoma peritonei is an infrequent clinical entity characterised by intraperitoneal mucinous/gelatinous ascites produced by the cancerous cells. It has been associated with gastrointestinal, gynaecological, lung and breast tumours. It is commonly asymptomatic and is most often detected incidentally on abdominopelvic imaging or laparoscopy. Higher histological grade of the tumour shows increased metabolic activity on 18F-Fluorodeoxyglucose (FDG) positron-emission tomography (PET) computed tomography (CT). It has been rarely reported in patients with sarcoma. We hereby present an interesting case of incidentally diagnosed pseudomyxoma peritonei on 18FDG PET-CT scan of a patient with soft tissue sarcoma of peripheral nerve sheath.

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.

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.

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.

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.

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.

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.

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.

"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.

Incidental COVID-19 pneumonia on oncologic 18F-FDG PET-CT scan in asymptomatic patient.

Corona virus disease 2019 (COVID-19), originated from Wuhan province of China, is responsible for causing severe respiratory syndrome (SARS-Cov-2). Initial specific investigation to diagnose the viral infection includes nasopharyngeal nucleic acid testing (RT-PCR). However other modalities can also aid in detection of COVID-19 infection. For instance, COVID pneumonitis related findings on positron emission tomography (PET/CT) scan acquired, during routine evaluation; can help in detection the viral infection in asymptomatic patients thereby preventing further spread of infection to other patients, physicians; and family members. This can alert physicians in taking prophylactic and preventive measures for management of these asymptomatic patient.

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.

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.

Incidental findings on a DXA scan: the unattended innocents.

Dual energy X-ray Absorptiometry (DXA) scan is the gold standard for assessing and monitoring bone mineral density. Clear guidelines are given by ISCD and other societies as to the appropriate use of this modality. However, as with other imaging modalities, a DXA scan can reveal incidental findings that must be mentioned in the report. Often times an adequate history of the patient will define the cause of nonspecific artifact on DXA imaging underscoring the importance of appropriate history taking for scanning.

Pyrexia of unknown origin as clinical presentation of Renal Cell Carcinoma: Role of F18-FDG PET/CT.

The synergy of the anatomic-metabolic details provided by PET-CT plays a substantial role in the diagnostic workup of Pyrexia of Unknown Origin (PUO). Although several imaging modalities have been used in the detection of cause of PUO, PET-CT is the most sensitive and specific modality for detection of cause. RCC is a rare cause of PUO.