Non-Hodgkin lymphoma dominated by multiple organ extranodal disease revealed on FDG PET/CT

Unusual Presence of Synchronous Primary Ovarian and Thyroid Extranodal Non-Hodgkin Lymphoma Without Lymph Node Involvement

ABSTRACT

Extranodal lymphomas without lymph node involvement are rarely observed and create diagnostic challenges. We present the case of a 33-year-old woman who was admitted with abdominal swelling. Ultrasonography findings suggested bilateral ovarian masses. 18 F-FDG PET/CT revealed intense uptake on the bilateral pelvic mass and thyroid gland. Following excisional surgery and thyroid fine-needle aspiration biopsy, the patient was diagnosed with diffuse large B-cell lymphoma. This case is exceptionally rare, as it presents 2 synchronous extranodal involvements in the ovaries and the thyroid gland independently while not presenting any lymph node activity, which has not been reported before.

18F-FDG PET/CT Findings in HIV-Positive Patient With Primary Pancreas Lymphoma and CMV Pancreatitis

ABSTRACT

A 35-year-old HIV-positive man with abdominal pain was referred to 18F-FDG PET/CT for metabolic characterization of mass in pancreas. PET/CT images showed intense FDG uptake in head of the pancreas, as well as diffuse moderate uptake throughout body and tail of the pancreas. Histopathological results revealed Epstein-Barr virus (EBV) associated large B-cell lymphoma and pancreatitis caused by cytomegalovirus.

Primary Pancreatic Lymphoma on FDG PET/CT

A 69-year-old man underwent FDG PET/CT to evaluate a right upper abdominal mass. The images showed peripherally increased activity with central photopenic region in the head of the pancreas, which was consistent with pancreatic malignancy. Histopathologic findings showed characteristic findings of diffuse large B-cell lymphoma. The activity was diminished on follow-up PET/CT after 8 courses of chemotherapy.

Multifocal Interdigitating Dendritic Cell Sarcoma Demonstrated on FDG PET/CT Imaging

Interdigitating dendritic cell sarcoma is a very rare malignancy that more commonly occurs in one anatomic location. Surgical resection of the lesion is the mainstay of the therapy. Multiple lesions at different locations are less common at the presentation. We report FDG PET/CT findings of multifocal interdigitating dendritic cell sarcoma in a 30-year-old woman.

FDG PET/CT Demonstrated Precursor B-cell Lymphoblastic Lymphoma in a Pediatric Patient With Hemophilia B

A 4-year-old boy with history of hemophilia B presented with increasingly enlarged scalp masses. Although they were initially thought as hematomas, unresponsiveness to the therapy lead to suspicion of malignancy, which prompted FDG PET/CT. The FDG PET/CT images demonstrated increased FDG uptake in the scalp masses and cervical lymph nodes. The pathology from the left scalp mass and the left cervical lymph nodes revealed precursor B-cell lymphoblastic lymphoma.

F-18 Fluorodeoxyglucose Positron-Emission Tomography-Computed Tomography in a Case of Extensive Multi-Organal Extranodal Lymphoma with Cardiac Involvement Mimicking Apical Hypertrophic Obstructive Cardiomyopathy: Staging and Response Evaluation

18F fluorodeoxyglucose positron-emission tomography/computed tomography (¹⁸F-FDG PET/CT) is a standard imaging tool in staging as well as response evaluation for lymphoma. Here, we present a young male with extensive extranodal lymphoma with cardiac involvement which presented as diffuse myocardial lesion mimicking hypertrophic obstructive cardiomyopathy. ¹⁸F-FDG PET/CT helped in the staging by revealing multiple systemic involvements. Interim PET after three cycles of chemotherapy showed a complete metabolic response to therapy in all the extranodal sites including the cardiac involvement, thus retrospectively confirming the lymphomatous involvement. Previous literature also conforms to the superior role of ¹⁸F-FDG PET/CT in the clinical management of extensive extranodal lymphoma.

Solitary Benign Schwannoma Mimics Residual Malignancy on FDG PET/CT

Schwannomas can be seen in pediatric patients with neurofibromatosis and occur generally in the limbs. Solitary schwannoma rarely occurs in pediatric patients who do not have neurofibromatosis. A 15-year-old girl with Hodgkin lymphoma in the neck underwent follow-up FDG PET/CT scan to monitor the response to the chemotherapy. Although her lesions in the neck were no longer visualized, one focal activity in her left upper back persisted. Excisional biopsy result demonstrated benign schwannoma.

Lymphoma Causing Gastrosplenic Fistula Revealed by FDG PET/CT

A 73-year-old man presented with fatigue and weight loss. He had CT-proven splenic mass with fistulous connection to the greater curvature of the stomach, which suggested abscess. FDG PET/CT confirmed gastrosplenic fistula in addition to active lymph nodes in the gastrohepatic ligament and epigastric region. Pathological examination after the biopsy of the spleen was consistent with diffuse large B-cell lymphoma. Chemotherapy was administered with close clinical follow-up and resulted in the resolution of fistula without requirement for surgery.

FDG PET/CT Findings of Nodular Sclerosis-Subtype Classic Hodgkin Lymphoma Presented as Mediastinal Nodal Lesions at Onset But as Predominant Osseous Disease at Relapse

Nodular sclerosis-subtype classic Hodgkin lymphoma in general manifests as bulky mediastinal lymphadenopathy but very rarely involves bones. We report FDG PET/CT findings of a 19-year-old man with pathology-proven, nodular sclerosis-type classic Hodgkin lymphoma. His initial FDG PET/CT scan at the diagnosis showed only hypermetabolic lymphadenopathy in the mediastinum. However, the FDG PET/CT acquired when the disease recurred 20 months later showed predominant osseous disease without additional nodal lesions outside the mediastinum.