Hyperostosis Frontalis Simulating Metastatic Deposits: Unmasked on SPECT-CT.

Skeletal scintigraphy has a pivotal role in detecting a number of bone pathologies, but it has its own limitations because of 2D image acquisition. Hybrid imaging acts as a savior in these cases where it is difficult to distinguish between benign and malignant lesions just on the basis of planar images. We present one such case of known breast carcinoma with abnormal increased radiotracer uptake in the skull which was difficult to characterize as benign lesion such as hyperostosis frontalis or metastatic osseous lesion. The importance of describing this case is to have a thorough understanding of hyperostosis patterns and to not confuse it with metastatic deposits in patients with known malignancies.

Metastatic PSMA avid prostate tumour with penile uptake; a rare metastatic site on PET-CT.

Prostate carcinoma is the most common malignancy in males and the second most common cause of mortality. Initially, metastatic prostate cancers tend to involve bones, but these tumours can involve any system. Gallium-68 prostate specific membrane antigen (PSMA) positron emission computed tomography (PET-CT) scan is indicated in prostate cancer patients if PSA levels are raised, and CT and bone scans are inconclusive. Metastatic penile involvement is a rare phenomenon. We present a case of prostate cancer with foci of PSMA uptake in the penile region. .

Lytic Bony Lesions On 18 F-FDG PET-CT Versus 99m Tc MDP Bone Scan.

With rising incidence of breast carcinoma in Asian population, staging workup remains a crucial entity in disease management and outcome. Bone scintigraphy for detection of osteoblastic metastasis has remained a convenient choice. However, in the presence of underlying lytic bony lesions sensitivity of 99mTc-MDP bone scan is questionable when compared to 18 F-FDG PET-CT scan. We present a case that showed better sensitivity of 18F-FDG PET-CT for picking up early lytic lesions for staging breast cancer.

Colloid gastric emptying with SPECT-CT after oesophagectomy.

Scintigraphic analysis of gastric motility uses the rate of gastric emptying by measuring radioactivity remaining in the stomach at pre-defined points in time. It helps to assess unresolved symptoms of functional gastrointestinal disorders such as gastroparesis. Delayed gastric emptying can occur in post-oesophagectomy patients. Squamous cell carcinoma of the esophagus is a common indication for oesophagectomy. In such patients presenting with post-prandial symptoms of bloating, nausea or vomiting, colloid scintigraphy can play a vital role in evaluation of their symptoms. We present an interesting image of a post-oesophagectomy patient with persistent gastric dilatation suspected of delayed gastric emptying.

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.

An unusual presentation of metastatic chondrosarcoma on Tc99m MDP Bone scan.

Radionuclide bone scintigraphy with technetium-99m-methylene diphosphonate is the commonest procedure in nuclear medicine. It is an effective diagnostic tool in staging of primary bone tumours since long. It is not only helpful to confirm the radiologic features of malignant bone tumours but also demonstrates skeletal metastasis and soft tissue involvement. Computed tomography (CT) combined with single-photon emission computed tomography (SPECT/CT) give better insight to localize and categorize the lesions. We describe an interesting image of chondrosarcoma showing anatomical extent of primary tumour and multifocal uptake in the chest conforming to underlying widespread partially calcified pulmonary metastases.

Hodgkin lymphoma with co-existing extramedullary haematopoiesis in a Thalasaemia Major patient: Killing two birds with one stone using PET-CT.

Hodgkin lymphoma is a high grade lymphoma which is usually confined to the lymphnodes. Extranodal involvement of the Hodgkin lymphoma is uncommon but any organ can be involved.. Extramedullary haematopoiesis is the production of red cells outside the medullary cavity in response to failure of erythrogenesis in bone marrow which can occur due to many diseases with thalassaemia and myelofibrosis being most common. We present a case of a 21 year old patient who underwent PET-CT scan for the staging of Hodgkin lymphoma and revealed co-existing extramedullary haematopoiesis secondary to known thalassaemia.

The crying child; physiological variant on F18-FDG PET-CT in a patient of langerhans cell histiocytosis.

F18-FDG PET-CT (Fluorodeoxyglucose Positron Emission Computed Tomography) scanning has a proven role in the staging of various cancers;the physiological distribution of F18-FDG must be understood thoroughly in order to improve the accuracy of image interpretation. We describe the case of a 2 year old child with Langerhans cell histiocytosis, who cried at the time of cannulation before undergoing F18-FDG PET-CT scanning.

False positive finding of F18-FDG in non-Hodgkins lymphoma; an inflamed appendix.

Although PET-CT scanning is a tremendous advancement in oncology; for accurate interpretation, it is important to understand its limitations. Not all PET-positive lesions are cancerous. Both activated macrophages and metabolically active carcinomas will accumulate F18-FDG. Due to limited specificity of FDG-PET/CT, histologic assessment may be required to establish correct diagnosis. We describe a case of 37-year-old man with non-Hodgkin's lymphoma, who underwent F18-FDG PET/CT at the completion of chemotherapy. Imaging showed metabolically active right pelvic soft tissue. Surgical resection confirmed appendicitis.

SINISTER CAUSE OF HIGH BONE MINERAL DENSITY ON DUAL ENERGY X-RAY ABSORPTIOMETRY.

Dual energy X-ray absorptiometry (DXA) has an established, well standardized role in the measurement of bone mineral density (BMD). In routine clinical practice, the main focus of bone densitometry is to identify low bone mass for the diagnosis and monitoring of osteoporosis particularly in postmenopausal females and in high risk individuals. Less commonly, elevated BMD can also be seen on routine DXA scanning usually due to degenerative disease. However, a range of other skeletal disorders can also lead to high BMD. Careful recognition of various artefacts and pathologic processes that can falsely elevate the BMD is essential for accurate DXA scan analysis and reporting. We present a case of high BMD in a patient of prostate carcinoma with widespread sclerotic metastases.

A Diagnostic Challenge: Erdheim Chester Disorder

Erdheim-Chester disease (ECD) is a rare, multisystemic, idiopathic disease often associated with BRAF V600E mutation. Its diagnosis is typically delayed and challenging due to its variable manifestations. Although it has an indolent course, advanced stages can manifest fulminant behavior with multiple vital organ involvement. It is a class 2a, non-Langerhans cell histiocytosis with characteristic radiological appearance. Whole body imaging might be helpful, particularly, to assess skeletal lesions. Although widespread disease with typical skeletal involvement on imaging can prompt diagnosis, histopathology with immunohistochemistry is required for confirmation. The disease can also manifest itself with a large variety of central nervous system related or orbital symptoms. Cardiac involvement is quite common. We present an interesting image of a patient with ECD who underwent PET/CT. Informed consent of the subject described in this image is waived by the Institutional Review Board.

Classical Hodgkin's Lymphoma with Skeletal Muscle Involvement: A Testing Case.

Skeletal muscle involvement in Hodgkin lymphoma is very rare. An 11-year male child presented with stage IV Hodgkin lymphoma and skeletal muscle involvement in right gluteal, piriformis and psoas muscles. He had resistant disease. He achieved remission with 3rd line chemotherapy, EPIC; and successfully underwent high dose chemotherapy with autologous stem cell rescue. The patient is well after 15 months of follow-up. Successful treatment signifies positron emission computed tomography (PET/CT) evaluation and multidisciplinary team discussions in diagnosis and management of a rare Hodgkin lymphoma presentation.

Survival Analysis of Papillary Thyroid Carcinoma in Relation to Stage and Recurrence Risk: A 20-Year Experience in Pakistan.

OBJECTIVE: The aim of this study was to evaluate the overall and progression-free survival of papillary thyroid carcinoma (PTC), comparing the American Thyroid Association (ATA) guideline for risk of recurrence with the TNM staging system with dynamic assessment at 2 years. PATIENTS AND METHODS: This study is a retrospective analysis of 689 PTC patients over a 20-year period at a single center. Disease-free survival based on the TNM staging and ATA recurrence risk was calculated using Kaplan-Meier curves. Dynamic response assessment during the first 2 years was compared for both systems. Survival was calculated based on age, baseline resectability, and postthyroidectomy serum tumor marker levels. RESULTS: Six hundred eighty-nine (72.2%) of the total thyroid cancer patients had PTC. Four hundred sixty-nine patients were females, and 220 patients were males. The age range was 6 to 87 years. Five hundred thirty-five patients were resectable, and 56 patients were unresectable. One hundred fifty-one patients were excluded due to insufficient information on recurrence risk. By ATA categorization, 39% had low risk, no disease-related mortality; 44% had intermediate risk, 3 died; and 17% had high risk, 32 died. The 5-year disease-free survival was 54%, 26%, and 5% in low-, intermediate-, and high-risk groups, respectively. The log-rank test showed a significant difference in the percent survival (P < 0.01). TNM stage wise, in terms of survival, 1.3% in stage I, 2.2% in stage II, 0% in stage III, and 37.5% in stage IV died. The 20-year disease-free survival showed the following: stage I, 43%; stage II, 28%; stage III, 18%; and stage IV, 2%. There is significant difference in survival rate (P < 0.01). Both ATA risk classification and TNM staging were significant predictors of disease-free survival. On bivariate analysis, ATA classification (hazards ratio, 2.1; 95% confidence interval, 1.64-2.67; P = 0.001) was better predictive of overall survival versus TNM classification (hazards ratio, 1.3; 95% confidence interval, 1.11-1.43; P = 0.063). CONCLUSIONS: The ATA risk stratification and continuous reassessment during the first 2 years predicts disease-free survival better than the TNM staging. Age older than 45 years, unresectable disease, and elevated postthyroidectomy thyroglobulin levels dictate a poorer prognosis.