Multiple Hypermetabolic Lesions Research Articles

8161 A Rare Case of Malignant Melanoma Metastatic to the Thyroid Gland

Abstract Disclosure: J. Ferri-Guerra: None. O. Abdulhussein: None. E. Kasper-Guerra: None. G. Madrigal Loria: None. L. El Hage: None. 69 yo female presented with neck swelling in 2014. TSH was normal. Thyroid ultrasound showed multiple nodules with a right 2.9 x 2.3 x 2.1 cm that was cold on subsequent thyroid uptake scan. FNA of the right nodule in 08/2014 showed malignant cells with spindle cell pattern thought to be medullary thyroid cancer. She was scheduled for total thyroidectomy but presented with small bowl obstruction prior to her surgery and was diagnosed with metastatic melanoma (BRAF +). Initial PET scan showed a 4.1 x 2.8 x 2.8 cm hypermetabolic right thyroid lobe lesion in addition to other multiple hypermetabolic lesions consistent with known melanoma. The thyroid FNA specimen correlated with the small bowel excision specimen and showed similar features diagnosing metastatic melanoma to the thyroid gland.She was started on ipilimumab with subsequent scan in 04/2015 showing increase in right thyroid mass size to 5.4 x 4.2 x 9 cm with mixed results of other metastatic locations. She was switched to pembrolizumab and later dobrafenib/trametinib in 05/2015. Imaging thereafter showing significant improvement including a decrease in the right thyroid nodule size to 1.6 cm x 2.5 cm x 2.4 cm with no hypermetabolic activity on further PET scans. Repeat thyroid ultrasound in 2021 showed multiple nodules with a 2.2 x 1.5 x 1 cm nodule in the right. Repeat FNA of the right nodule was benign. Last imaging in 2023 showed stable nodules. Conclusion: metastasis to thyroid gland from malignant melanoma is a rare finding and should be considered in rapidly growing thyroid nodules. These lesions can be treated with targeted therapy that can spare affected individuals surgery. Presentation: 6/1/2024

Primary Leiomyosarcoma of Suprahepatic Inferior Vena Cava with Metastases.

A 67-year-old female presented with shortness of breath, weight loss, abdomen, and back pain for 2 months. Ultrasound of the abdomen revealed multiple focal liver lesions. 18F-Fluorodeoxyglucose whole-body positron emission tomography/computed tomography revealed a hypermetabolic lesion in the suprahepatic inferior vena cava extending into the right atrium. Multiple hypermetabolic lesions were seen in liver, bones, and abdominal lymph nodes, suggestive of metastases. Histopathology and immunohistochemistry of the lesions revealed it to be metastatic leiomyosarcoma.

CD8+ aggressive T-cell lymphoma (T-NHL) involving the liver and skin: a case study

Abstract Introduction/Objective Aggressive T-NHL involving cutaneous and visceral organs is rare. We report a case with a complex presentation that was found to have hepatic and skin lesions simultaneously. We emphasize the importance of the clinicopathological correlation and diagnostic work-up for such a rare case Methods/Case Report A 60-year-old male with alcoholic cirrhosis presented with abdominal pain, fever, and night sweats for over two weeks. Detailed physical evaluation revealed a tender, indurated, erythematous papule on the left upper back. Lab results showed leukopenia, anemia, and increased LDH. PET-CT showed multiple hypermetabolic lesions in the liver, skin, and deep soft tissue above and below the diaphragm. A liver biopsy revealed a diffuse sheath of large atypical lymphoid cells with small lymphocytes in the background. Atypical lymphoid cells stained positive for CD45, CD2, CD3, CD8, TIA-1, CD5 (partial), granzyme B (partial), βF1 (partial); and negative for ALK, BCL-2, CD4, CD7, CD10, CD30, CD56, and TCRδ. Ki-67 was 70%. The skin punch biopsy revealed epidermotropic infiltration of lymphocytes with a similar immunophenotype as the liver lesion. Bone marrow biopsy showed no involvement. The differential diagnosis includes primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-NHL with visceral dissemination, peripheral CD8+ T-NHL, lymphomatoid papulosis, CD8-positive mycosis fungoides, and hepatosplenic T-NHL. The visceral involvement excludes lymphomatoid papulosis and CD8-positive mycosis fungoides. The absence of bone marrow involvement excludes hepatosplenic T-NHL. The prominent liver involvement favors the diagnosis of peripheral CD8+ T-NHL. However CD8+ aggressive epidermotropic cytotoxic T-NHL still cannot be entirely excluded due to the epidermotropic CD8 positive T-cell infiltration of the dermis and subcutaneous adipose tissue. Further evaluation for JAK2 mutation and TBX21 amplification can help distinguish it from Peripheral CD8- positive T-NHL. Results (if a Case Study enter NA) NA Conclusion The subclassification of CD8+ T-NHL into distinct entities with overlapping clinical and histological characteristics is challenging without molecular tests. However, clinicopathological correlation with appropriate work-up can help narrow the differential diagnoses.

Transformed Giant Congenital Melanocytic Nevus on 18 F-FDG PET/CT.

A 50-year-old man experienced cough and bloody sputum for 1 month. CT detected a mass in the right lung. Staging 18 F-FDG PET/CT revealed multiple hypermetabolic lesions in the lung, mediastinum, liver, and bones. Further physical examination revealed black patches in the skin covering most parts of the body, which presented at his birth and were growing very slowly, consistent with giant congenital melanocytic nevus. Pathology examination after biopsy of the lung demonstrated metastatic melanoma.

Extranodal involvement of posttransplant lymphoproliferative disorder detected on 18F‐fluorodeoxyglucose‐positron emission tomography/computed tomography

A 69-year-old man with a history of kidney transplantation presented with ring-enhancing lesions in the left frontal lobe, thalamus, and right insula (Figure 1a) on magnetic resonance imaging. He was hospitalized with a diagnosis of cytomegalovirus encephalitis and had taken anti-inflammatory therapy. Follow up imaging showed a decrease in lesion size in the left frontal lobe and thalamus; however, the right insular lesion increased in size and new ones were identified in the corpus callosum and periventricular white matter (Figure 1a). The tumor markers CA125, CYFRA21-1, CEA, PSA, and fPSA were all positive on blood testing. Because anti-inflammatory therapy was ineffective and malignant tumor could not be excluded on imaging alone, whole-body 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) was performed (Figure 1b). Body imaging showed multiple hypermetabolic nodular lesions in the thoracic and abdominal superficial soft tissue (maximum standardized uptake value, 13.06), which suggested malignancy. Head imaging showed decreased activity in the brain lesions. A diagnosis of lymphoma was suspected. Punch biopsy of a superficial soft tissue nodule was consistent with B cell-derived posttransplant lymphoproliferative disorder (PTLD) (Figure 1c,d). Brain MRI, 18F-FDG PET, and histopathological findings in a 69-year-old male patient with posttransplant lymphoproliferative disorder. (a) Abnormal signals in T2-flair MRI images within 3 months (solid arrow). (b) 18F-FDG PET/CT images show multiple lesions in superficial soft tissue nodules with hypermetabolism and decreased FDG activity of intracranial lesions (solid arrow). (c) Immunohistochemical staining shows positive CD3. (d) Immunohistochemical staining shows enlarged B cells (solid arrow). 18F-FDG, 18F-fluorodeoxyglucose; CT, computed tomography; PET, positron emission tomography. PTLD is a rare group of heterogeneous lymphoproliferative conditions that occur after solid organ or hematopoietic transplantation [1, 2]. With allograft transplantation, the anatomic site of PTLD involvement usually depends on the type of transplant [3]. Reported incidence rates of involvement of the central nervous system range between 10% and 15% [4, 5]. However, simultaneous involvement of the central nervous system [6] and superficial soft tissue [7] are rare. To date, only two cases of PTLD soft tissue nodules have been reported [4]. Characteristics of PTLD on magnetic resonance imaging are not specific; however, PTLD can be detected on 18F-FDG-PET with an overall sensitivity and specificity of approximately 90% [8, 9]. PTLD should be considered when multiple hypermetabolic superficial soft tissue nodules and central nervous system lesions are encountered in transplantation patients. Whole-body18F-FDG-PET/CT is more effective than single-site imaging for diagnosing or staging PTLD. Bojun Wang: Data curation (lead); Writing – original draft (lead). Tianbin Song: Conceptualization (equal); Writing – review & editing (equal). Chun Zhang: Conceptualization (equal); Supervision (equal). Jie Lu: Supervision (equal). Zhigang Liang: Supervision (equal); Writing – review & editing (equal). We thank Dr. Lianghong Teng (Department of Pathology, Xuanwu Hospital, Capital Medical University, Beijing, China) who provided support of pathological picture of this case. All the authors declare that they have no conflict or potential conflict of interest. This article does not contain any studies with animals performed by any of the authors. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the principles of the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards. Informed consent was obtained from the patient and his parents for the anonymous use of his clinical, imaging, and histologic data for publication. The data that support the findings of this study are available from the corresponding author, upon reasonable request.

Multimodality imaging evaluation of nasal sinus alveolar rhabdomyosarcoma: Two case reports

Rhabdomyosarcoma (RMS) is a common pleomorphic malignant soft tissue sarcoma in children and adolescents that originates from rhabdomyoblasts or mesenchymal precursor cells. Alveolar rhabdomyosarcoma (ARMS) mostly occurs in adolescents aged 10-15 years and is characterized by more aggressive behaviors and worse prognosis than other sarcomas, prone to lymphatic and hematogenous metastasis in the early stage as well as metastasizing to breast, testis, pancreas, and other parts. ARMS often occurs in the limbs and genitourinary system, however, head and neck ARMS are relatively rare when involving the nasal cavity or sinuses. The role of MRI and 18F-FDG positron emission tomography combined with computed tomography (PET/CT) remains to be established in ARMS. Case 1: An 18-year-old male was found with a left submandibular mass of approximately 1 cm in diameter 2 months ago, which gradually increased in size. CT showed multiple soft tissue masses in maxillofacial and neck regions and the lesions invaded the frontal lobe and the inner wall of the left orbital lobe. MRI showed the masses with hypointensity on T1WI, hyperintensity on T2WI, and diffusion-weighted imaging (DWI) with significant enhancement. 18F-FDG PET/CT showed multiple hypermetabolic lesions located in the maxillofacial, neck region, 3rd lumbar vertebra, and the right sacrum. A nasal endoscopic tumor biopsy and molecular testing finally helped to diagnose the ARMS. Case 2: A 14-year-old male presented with left maxillary pain with nasal congestion and left ocular swelling 15 days ago. CT demonstrated a soft tissue mass in the nasal cavity and sinuses with local protrusion into the left orbit. MRI showed the masses with a slightly low signal on T1WI, a high signal on T2WI, and DWI with significant heterogenous enhancement. 18F-FDG PET/CT showed hypermetabolic lesions in the left maxillofacial and neck regions. ARMS was finally diagnosed by a nasal endoscopic tumor biopsy and molecular testing. The patient had a recurrence of the lesion after chemotherapy and surgical resection and is currently undergoing radiation therapy. Nasal sinus ARMS is highly malignant with a poor prognosis. Accurate diagnosis relies not only on histopathology and immunohistochemistry examination but also on genetic detection of characteristic chromosomal translocations and fusion genes. Imaging methods, such as MRI and PET/CT can accurately assess the extent of the lesions and metastases, assist in the diagnosis of the disease and the selection of treatment regimens, provide precise localization for surgery, and help with treatment monitoring and follow-up.

Unusual Recurrence of Malignant Melanoma After 14 Years, diagnosed by 18F-FDG PET-CT Imaging: A Case Report

According to the World Health Organization, the number of malignant melanoma cases increases faster worldwide. Early diagnosed and adequately managed malignant melanoma shows a good prognosis. Rare cases of late metastasis of melanoma after long disease free survival, and their growing incidences are reported. This reported case is about a metastatic malignant melanoma who was apparently disease free for 14 years but showed late recurrence and earned clinical interest. A 60-year-old male patient was referred to PET-CT division of National Institute of Nuclear Medicine & Allied Sciences (NINMAS) for the evaluation of a biopsy proven malignant melanoma in right inguinal region. The patient presented with a newly developed asymptomatic nodule on his right thigh. Relevant past medical history included a completely excised lesion in his left axilla for malignant melanoma. Fine-needle aspiration and cytological analysis report of new lesion showed subcutaneous localization of malignant melanoma. 18F-FDG PET-CT imaging showed hypermetabolic soft tissue density mass in right inguinal region; Histopathology report (HPR) proved malignant lesion. Multiple hypermetabolic lesions were seen intra abdominally involving spleen and pancreas with corresponding hypodense lesions on CT scan. Multiple hypermetabolic enlarged intraabdominal, right axillary and right inguinal lymph nodes are also evident. After 14 years of disease free survival the reported case developed malignant melanoma with distal metastases. Although late metastasis is uncommon however physicians should be aware of any newly developed suspicious lesions and PET-CT can play an important role in workup for detection of metastases from melanoma. Bangladesh J. Nuclear Med. 25(1): 45-47, 2022

Idiopathic Lobular Panniculitis with Extensive Hypermetabolic Lesions in FDG PET-CT Scan: Case Report

Panniculitis indicates ‘inflammation of fat tissue’. Idiopathic Lobular Panniculitis is a rare condition in which inflammation occurs in the subcutaneous tissue, just beneath the skin. It is predominantly observed in women in the age group of 30-60 years. Occasionally, children may also be affected. We report a case of a 57 years old woman, who presented with multiple palpable skin lesions in both thigh, upper arms, breast and facial site specially left cheek and submandibular area. All of her laboratory findings including hematological and biochemical parameters were normal except slightly low white blood cell count. 18FDG PET-CT revealed multiple hypermetabolic lesions in the subcutaneous layer of skin and fat layers of the retroperitoneum. Diagnosis was confirmed by surgical biopsy which was reported as lobular panniculitis. Distinguishing true malignant cutaneous and subcutaneous benign might be difficult, but when lesions show high uptake of FDG, it can be related to an active inflammation. Extensive FDG uptake in a benign case like this is rare. Therefore, 18FDG PET-CT is not only helpful in detecting panniculitis but also feasible for identifying active state of the disease. Bangladesh J. Nuclear Med. 24(1&2): 57-59, 2021

ADENOCARCINOMA OF THE LUNG PRESENTING AS AN ACUTE STROKE: THE CLINICAL CHALLENGE OF NONBACTERIAL THROMBOTIC ENDOCARDITIS

SESSION TITLE: Medical Student/Resident Lung Cancer Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Nonbacterial Thrombotic Endocarditis (NBTE) is an under recognized etiology of new heart murmurs and systemic emboli. Caused by aseptic fibrin and platelet aggregates on heart valves due to an underlying hypercoagulable state such as malignancy, NBTE carries high morbidity and mortality and is often a post-mortem diagnosis. Treatment involves systemic anticoagulation, valve repair and tailored management of the primary condition. CASE PRESENTATION: A 66-year-old man was referred to the Pulmonology clinic for evaluation of an 8cm x 6 cm right lower lobe cavitary mass with associated hilar and mediastinal lymphadenopathy, which was incidentally found during a recent hospitalization for a cerebrovascular accident. His medical history was significant for hypertension and a recent right middle cerebral artery stroke with residual left hemiparesis and scattered infarcts throughout bilateral parietal lobe and cerebellum. He reported a 35 pack-year tobacco smoking history and a 30-pound unintentional weight loss but denied respiratory symptoms. Physical exam showed left arm weakness, but was otherwise unremarkable. As part of the stroke work up, a transthoracic echocardiogram showed thickening and calcification of the aortic leaflets. NBTE was suspected in the setting of a possible lung neoplasm. A transesophageal echocardiogram was performed and showed a 0.8 cm x 0.8 cm solid vegetation at the tip of the right coronary cusp of the aortic valve. Infective endocarditis was ruled out via negative blood cultures and the absence of fever or septic features. A PET-CT scan revealed multiple hypermetabolic lesions in the lower and middle lobes of the right lung, N1, N2 lymph nodes, left adrenal gland and in the soft tissue of the right scapula. Histopathology of the scapular lesion was consistent with adenocarcinoma of the lung that was EGFR/BRAF/ALK/ROS1 negative, KRAS positive with PD-L1 50% expression. He was started on Pembrolizumab and palliative chemotherapy. Since the patient ultimately opted for hospice care, anticoagulation therapy was not initiated. DISCUSSION: Serious neurocognitive impairment and other cerebrovascular complications as the result of recurrent embolization worsen the overall prognosis of patients with NBTE. Therefore, a high index of suspicion for prompt diagnosis and treatment of the underlying cause is critical. CONCLUSIONS: Underlying malignancy must be considered in the differential diagnosis of a patient with systemic emboli, aseptic endocarditis and constitutional symptoms. Reference #1: Bussani R, De-Giorgio F, Pesel G, et al. Overview and Comparison of Infectious Endocarditis and Non-infectious Endocarditis: A Review of 814 Autoptic Cases. In Vivo. 2019;33(5):1565-1572. Reference #2: Petrescu I, Aung H, Ionescu F, et al. Nonbacterial Thrombotic Endocarditis Despite Anticoagulation with New Oral Anticoagulants. Journal of the American College of Cardiology. 2018;71(11):A2308 DISCLOSURES: No relevant relationships by Nabeel Azzawi, source=Web Response No relevant relationships by Roberto Pineda-Reyes, source=Web Response No relevant relationships by Natarajan Rajagopalan, source=Web Response No relevant relationships by Irene Riestra Guiance, source=Web Response

False positive finding from malignancy-like lesions on FDG PET/CT: case report of tuberculosis patients

BackgroundThe F-18 fluorodeoxyglucose positron emission/computed tomography (FDG PET/CT) has become an established diagnostic imaging for malignancy. However, there are other diseases that can also be identified with FDG, some of them are infections such as tuberculosis.Case presentationIn this case report, two patients showed multiple hypermetabolic tuberculosis lesions on FDG PET/CT, with one of the patients having history of malignancy. The objective of the present case report is to emphasize the need to use other differential diagnosis techniques for tuberculosis especially in tuberculosis-endemic countries when interpreting FDG PET/CT.ConclusionBy analyzing diagnostic imaging alone, there is a high chance of misinterpreting asymptomatic tuberculosis patient as having malignancy. Therefore, there is need for correlation with clinical data as well as other imaging modalities and PET/CT with more specific tracer in order to differentiate malignancy from benign disease such as tuberculosis.

RARE-48. GROWING KNOWLEDGE AND EMERGING QUESTIONS RELATED TO POT-1 GERMLINE MUTATIONS AND ASSOCIATED MALIGNANCIES: A CASE REPORT

Abstract Protection of telomeres 1 (POT1) is a member of a family of genes responsible for maintenance of telomere integrity. Germline mutations of the POT1 gene have been associated with tumorigenesis of multiple tissue types, conferring an increased risk of development of malignancies such as melanoma, chronic lymphocytic leukemia, gliomas, and cardiac sarcomas. We present the case of a 28 year old male who first presented at the age of 15 with personality changes. Several years later, he was found to have a left frontal, IDH mutated, WHO grade III anaplastic astrocytoma. Following successful treatment with gross total resection, radiation therapy, and adjuvant chemotherapy, the patient represented with an MRI showing enhancement concerning for osteomyelitis and possible tumor recurrence. Pathology of the dura was consistent with myxofibrosarcoma. Staging PET scan at that time revealed multiple hypermetabolic lung lesions found to be Lanagerhans cell histiocytosis. Given the patient’s complex oncological history, genetic testing was performed. He was found to carry a heterozygous mutation of the POT1 gene. This case raises the suspicion for a broader POT1-associated cancer predisposition than previously described in the literature. Moreover, this prompts further questioning of an association between POT1 mutations and IDH status in related gliomas. Patients with POT1 mutations might also be at increased risk of secondary malignancies after radiation exposure, which may require closer observation after treatment.

SUN-606 Thyroid Cancer Presenting As Acute Limb Ischemia

INTRODUCTION: Cardiac metastases are present in up to 20% of patients with extra-cardiac malignancies and are 40 times more common than primary cardiac tumors. However, thyroid cancer metastatic to the heart is rare. We report a case of mixed follicular and papillary thyroid carcinoma with the presence of anaplastic features presenting with cardiac metastasis. CASE: A 52-year old female non-smoker was admitted with right arm ischemia. Two years earlier, she had been diagnosed with thyroid cancer and underwent total thyroidectomy. Surgical pathology at the time revealed multifocal follicular and papillary thyroid cancer with focal anaplastic changes and positive central lymph nodes. She was treated with 150mCi RAI for remnant ablation, with the post treatment whole-body scan revealing radiotracer activity in the neck but no scintigraphic evidence of distant metastases. She was subsequently lost to follow-up. At the time of admission, she was found to have acute limb ischemia due to axillary artery thrombosis and underwent fasciotomy and embolectomy. Chest CT revealed multiple cavitary lung lesions and a left ventricular mass with adherent thrombus. Biopsy of the lung lesions confirmed metastatic poorly differentiated thyroid cancer (immunohistochemical staining positive for Pax8, TTF-1 and P40, but negative for thyroglobulin). PET scan showed multiple hypermetabolic lesions, including bilateral pulmonary nodules, right hilar adenopathy, a left ventricular mass, and right hepatic lobe lesion. Mutational analysis showed BRAF V600E mutation. The patient is receiving salvage chemotherapy with dabrafenib/ trametinib. DISCUSSION: While rare, follicular carcinoma is the most common thyroid cancer with cardiac metastasis, mostly involving the central veins and right atrium. Papillary thyroid cancer tends to metastasize through the lymphatic system and involve the right side of the heart. The aggressive behavior of our patient’s tumor, with involvement of the left heart suggestive of vascular metastasis, is likely due to the concurrent presence of anaplastic de-differentiation. Anaplastic carcinomas are highly aggressive neoplasms and 71% are said to occur simultaneously with a well-differentiated thyroid cancer. About 50% of patients diagnosed with anaplastic thyroid cancer have metastatic disease at the time of diagnosis and another 25% develop metastasis during the course of disease. The prognosis is very poor with median survival ranging from 4-12 months.

Multiple bone hypermetabolic lesions caused by non-tuberculosis mycobacteria infection in 18F-FDG PET/CT: a case report

Multiple bone hypermetabolic lesions caused by non-tuberculosis mycobacteria infection in 18F-FDG PET/CT: a case report

Diffuse Large B-Cell Lymphoma Presenting as a Pancreatic Mass

Primary lymphomas of the gastrointestinal tract are rare; however is the most common site of extranodal involvement. When presenting as a primary lesion, a distinction from an epithelial malignancy is critical given the difference in therapy and prognosis. Primary pancreatic lymphomas represent cancer. On physical exam, he looked chronically ill, had pale conjunctiva, tenderness to palpation in epigastric area,and palpable inguinal lymphadenopathy. Initial CBC, chemistries and liver function tests were unremarkable. LDH was elevated and CA19-9 level was normal. An abdominal CT revealed a pancreatic tail mass measuring 3.1 x 2.3 cm associated with duodenal wall thickening, peripancreatic, supraclavicular, mediastinal and inguinal lymphadenopathy. Also, a cardiac intraventricular mass that measured 6.3 x 4cm was seen occluding almost all the right ventricle.Important to note is that the liver was unremarkable. A PET CT scan showed multiple FDG-avid lesions including the pancreatic tail and cardiac masses, with a foci of highest tracer uptake near the duodenum. An ultrasound guided biopsy of a neck nodule for immunohistochemistry showed large cells with vesicular nuclei and prominent nucleoli; the cells stained positive for CD20, CD45, suggesting diffuse large B-cell lymphoma (DLBCL). He received rituximab,cyclophosphamide, doxorubicin, vincristine, prednisone, and entecavir.Figure: Pancreatic tail mass approximately 3.1 x 2.3cm.Figure: There is a foci of severe high tracer uptake of the pancreas.Figure: Multiple hypermetabolic lesions are evident.After completion of first course, he was discharged home. While at home he developed gastrointestinal bleeding that required hospitalization. At that time and while his performance status declined, he refused further treatment. This case shows that a distinction between DLBCL and pancreatic adenocarcinoma is challenging but extremely important since treatment and prognosis are very different. This patient presented with abdominal symptoms and radiologic evidence of a pancreatic mass with regional and distant lymphadenopathy initially suggesting a primary pancreatic neoplasm. However, the absence of liver metastases, B symptoms, cardiac involvement and the extensive lymphadenopathy suggested a lymphoproliferative disease. The early suspicion of this rare presentation of Non-Hodgkin's lymphoma involving the pancreas, duodenum and right ventricle helped establish timely and appropriate therapy given the high mortality associated with this disease.

Occult Renal Granulomatous Inflammatory Lesions in Granulomatosis with Polyangiitis Detected by 18F-FDG PET/CT

A 33-year-old woman with a 7-month history of granulomatosis with polyangiitis F-FDG PET/CT scan due to low-grade intermittent fever and elevation of serum inflammatory markers, which revealed multiple hypermetabolic lesions in bilateral kidneys. Biopsy of a lesion showed granulomatosis with polyangiitis, consistent with renal involvement of granulomatosis with polyangiitis.

Cerebral Toxoplasmosis Masquerading Cns Lymphoma on FDG PET-CT in Post Renal Transplant Patient.

20 year old post renal transplant patient developed recurrent episodes of seizure. MRI revealed focal lesion in right parieto-occipital lobe with perilesional edema. FDG PET-CT revealed multiple hypermetabolic lesions in bilateral cerebral hemisphere. Subsequent biopsy from the lesion demonstrated bradyzoites of Toxoplasma gondii with inflammatory cells and thereby, a confirmatory diagnosis of cerebral toxoplasmosis was made. This case demonstrates the fact that increased FDG uptake in cerebral lesions in post transplant patient should be interpreted with caution and confirmed with histopathological correlation.

Mucoepidermoid Carcinoma with Distant Metastases to the Kidney, Adrenal Gland, Skull and Gluteus Maximus Muscle: a Case Report

Introduction: Distant metastases of mucoepidermoid carcinoma (MEC) are reported with the most common sites being the soft tissue of skin, lung, liver, and bone. We report here a very rare case of MEC with multiple metastases to the kidney, adrenal gland, skull and gluteus maximus muscle. Case report: A 63-year-old male patient presented with left-sided headache. Radiologic evaluations including CT and MRI showed ill-defined soft tissue lesion involving the left infratemporal fossa and left sphenoid sinus, and multiple enlarged lymph nodes in neck and mediastinum. PET-CT demonstrated multiple hypermetabolic lesions in and around the left kidney, left adrenal gland, right ischium, right gluteus maximus and skull base. These lesions were confirmed as MEC with multiple metastases through biopsy. Discussion: Only one case of metastasis to the skull has been previously reported, and moreover, there has not been a case of metastatic MEC to the kidney, adrenal gland and gluteus maximus muscle so far in the medical literature. It is important to acknowledge the possibility of every unusual MEC metastases, since the presence of metastasis has statistically significant influence on the survival of MEC.

Secondary neurolymphomatosis of spinal nerve roots detected by ¹⁸F-FDG PET/CT: a case report and differential diagnosis of the case.

Neurolymphomatosis (NL) is a rare neurological manifestation of lymphoma. Clinical symptoms of NL differ greatly according to the sites involved and diagnosis with conventional imaging techniques may sometimes be difficult. We herein describe the case of a 58 years old man presenting as radiculopathy with a history of non-Hodgkin's lymphoma (NHL). Computed tomography (CT) was unrevealing and magnetic resonance imaging (MRI) was contraindicated. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) was performed and revealed multiple hypermetabolic lesions along the nerve roots, which corresponded to the patient's neurological symptoms. A differential diagnosis of patients with lymphomatous involvement of spinal nerve roots has been presented. Our case suggests that ¹⁸F-FDG PET/CT successfully detected the infiltration of spinal nerve roots of NL due to lymphoma.

Pituitary carcinoma with different hormone expressions

Objective To introduce the experience of diagnosing and treating one case of pituitary carcinoma with distinct hormone expressions in primary and metastatic lesions and to improve understanding of this disease. Methods Retrospective study was performed to analyze the clinical manifestations, imaging characteristics, histopathologic findings, and treatment information of the patient. Immunohistochemical staining was done to both primary and metastatic lesions. Results The patient presented with eye pain and discomfort 4 months posterior to pituitary adenoma surgery. Head MRI showed multiple abnormal intracranial signals, irregular pituitary contour, and abnormal enhancements of the sellar region. PET-CT scan showed multiple hypermetabolic lesions. After the first surgery, histological study of the pituitary tumor showed disseminated tumor cells. The cells were round-shaped or polygonal, with mild atypia, moderate amount of eosinophilic plasma and round-shaped nuclei with fine chromatin and unconspicuous nucleoli; mitosis was abundant, while necrosis was absent. The tumor cells expressed P53, chromogranin A (CgA), with scattered expression for growth hormone (GH) and a Ki-67 index of 80% by immunohistochemistry. The first pathologic diagnosis was atypical pituitary adenoma. The parietal tumor cells infiltrated parenchymal after the tumor recurrence. Immunohistochemistry findings were different from the first one. The tumor cells expressed GH diffusely, with a decreased Ki-67 index of 75%. The second pathologic diagnosis was metastatic pituitary carcinoma. Conclusions Pituitary carcinoma is a rare malignant pituitary tumor. Diagnosis relies on radiology and pathology. Surgical resection and radiochemotherapy are the current treatment of choice but yield poor response. General prognosis of the disease is poor. DOI: 10.3969/j.issn.1672-6731.2015.01.013

Preoperative and Postoperative 18FDG PET/CT and Bone Scintigraphy Images in a Patient With Parathyroid Adenoma

A 35-year-old male patient with generalized body pain had multiple hyperactive lesions on bone scan, suggestive of metastatic disease. FDG PET/CT scan performed 2 weeks later showed multiple hypermetabolic lesions on skeletal system; also a hypermetabolic and hypodense lesion was present adjacent to the left thyroid lobe, suggestive of primary parathyroid adenoma and multiple brown tumors. Serum parathyroid hormone level was elevated, and parathyroid scintigraphy confirmed parathyroid adenoma. The patient underwent parathyroidectomy operation, and histopathology result revealed parathyroid adenoma. Five months after the operation, complete metabolic regression was observed on PET/CT, whereas bone scan did not show any significant difference.