Hodgkin disease (HD) and non-Hodgkin lymphoma (NHL) represent a spectrum of malignant neoplasms arising from the lymphoid system with an incidence of around 8% of all malignancies. Although they are generally known as tumors of lymph nodes, 25% to 40% of HD/NHL tumors, especially NHL, arise at extranodal sites along the gastrointestinal tract, head and neck, orbit, central and peripheral nervous system, thorax, bone, skin, breast, testis, thyroid, and genitourinary tract. Extranodal involvement is an important pretreatment prognostic factor for patients with lymphoma and its incidence has increased in the past 2 decades. Imaging plays an important role in the noninvasive pretreatment assessment of patients with extranodal lymphoma. This involvement can be subtle and may be overlooked during computed tomography (CT). Positron emission tomography/CT (PET/CT) has evolved into an important imaging tool for evaluation of lymphomas, facilitating the detection of affected extranodal sites even when CT shows subtle or no obvious lesions. Familiarity with extranodal manifestations and suggestive PET/CT features in different sites is important for accurate evaluation of lymphoma. This article reviews the extranodal PET/CT imaging findings regarding HD and NHL.

The purpose of this study was to determine the clinical significance of 18F-FDG PET/CT on initial staging and therapy planning in patients with invasive breast cancer. One hundred and forty-one consecutive, biopsy proven preoperative and 195 postoperative high-risk breast cancer patients who were referred for PET/CT for initial staging were included in this retrospective study. The clinical stage had been determined by conventional imaging modalities prior to the PET/CT scan. Of the 141 examined preoperative patients, 19 had clinical stage I (T1N0), 51 had stage IIA (12 T2N0 and 39 T1N1), 49 had stage IIB (2 T3N0 and 47 T2N1), 12 had stage IIIA (11 T3N1, 1 T2N2), 2 had stage IIIB (2 T4N1) and 8 had stage IV. PET/CT modified the staging for 26% of stage I patients, 29% of stage IIA patients, 46% of stage IIB patients, 58% of stage IIIA patients and 100% of stage IIIB patients. PET/CT scans detected extra-axillary regional lymph nodes in 14 (9.9%) patients and distant metastasis in 41 (29%) patients. PET/CT scans detected multifocal lesions in 30 (21%) patients, multicentric lesions in 21 (14%) patients and malign foci in the contralateral breast (bilateral breast cancer) confirmed by biopsy in 5 (3.5%) patients. Of the examined 195 postoperative patients PET/CT detected axillary lymph nodes in 22 (11%) patients, extra-axillary regional lymph nodes in 21 (10%) patients and distant metastasis in 24 (12%) patients. PET/CT findings altered plans for radiotherapy in 22 (11%) patients and chemotherapy was adapted to the meta-static diseases in 24 (12%) patients. PET/CT was revealed to be superior to conventional imaging modalities for the detection of extra-axillary regional metastatic lymph nodes and distant metastases. These features make PET/CT an essential imaging modality for the primary staging of invasive breast cancer, particularly in patients with clinical stages II and III.

TCV has a higher incidence of local or distant metastasis and mortality rate. Thus, it must be treated with the highest possible I ablation doses and followed up carefully.