Fat necrosis may mimic local recurrence of breast cancer in FDG PET/CT / La necrosis grasa puede asemejarse a una recurrencia local del cáncer de mama en la PET/TC con FDG

Fat necrosis of the breast is a benign condition that most commonly occurs as the result of trauma. The radiographic and clinical significance of fat necrosis of the breast is that it may mimic malignancy. We present a case of false positive FDG PET/CT scan caused by fat necrosis and mimics local recurrence of breast carcinoma 3 years after radical mastectomy. Physicians must be aware of fat necrosis as a potential pitfall for PET/CT. Fat necrosis must be considered in the differential diagnosis of hypermetabolic breast masses in patients who previously had mastectomy or mammoplasty (AU)

La necrosis grasa de mama constituye una situación benigna que se produce de forma común como resultado de un trauma. El significado radiográfico y clínico de la necrosis grasa puede asemejarse a una neoplasia. Presentamos el caso de un resultado falso positivo de la PET/TC con FDG debido a una necrosis grasa, y su semejanza con una recurrencia local de carcinoma de mama a los 3 años de una mastectomía radical. Los facultativos deben ser conscientes de que la necrosis grasa puede constituir una limitación para el estudio PET/TC. La necrosis grasa debe considerarse en el diagnóstico diferencial de las masas hipermetabólicas de mama en pacientes sometidas previamente a mastectomía o mamoplastia (AU)

Fat necrosis may mimic local recurrence of breast cancer in FDG PET/CT.

Fat necrosis of the breast is a benign condition that most commonly occurs as the result of trauma. The radiographic and clinical significance of fat necrosis of the breast is that it may mimic malignancy. We present a case of false positive FDG PET/CT scan caused by fat necrosis and mimics local recurrence of breast carcinoma 3 years after radical mastectomy. Physicians must be aware of fat necrosis as a potential pitfall for PET/CT. Fat necrosis must be considered in the differential diagnosis of hypermetabolic breast masses in patients who previously had mastectomy or mammoplasty.

The incidence of secondary central nervous system involvement in patients with non-Hodgkin's lymphoma as detected by 18F-FDG PET/CT.

AIM: Secondary central nervous system (CNS) involvement is a devastating and usually fatal complication of non-Hodgkin's lymphoma (NHL). We aimed to evaluate the incidence of secondary CNS involvement and the value of (18)F-FDG PET/computed tomography (CT) imaging in the detection of secondary CNS involvement in patients with NHL. METHODS: A total of 123 immunocompetent patients (58 men, 65 women; mean age: 56.5±19.2) with biopsy-proven NHL who underwent (18)F-FDG PET/CT for primary staging (n=68) and restaging (n=55) of recurrent disease were reviewed retrospectively. Those with secondary CNS involvement as diagnosed on PET/CT were identified. CNS involvement was confirmed by MRI and cerebrospinal fluid cytology. RESULTS: The clinical Ann Arbor stages of the patient population were as follows: stage I - 10 patients; stage II - 44 patients; stage III - 32 patients, and stage IV - 37 patients. PET/CT detected CNS involvement in six patients. The ages of patients with CNS disease ranged from 23 to 68 (mean: 47.2) years. Three patients presented with CNS involvement associated with systemic disease manifestation at initial diagnosis; one patient had isolated CNS relapse and two had relapsed systemic NHL with progression to CNS involvement. Relapse interval was 8-12 months following initial diagnosis. The types of CNS involvement in patients were as follows: parenchymal (n=2), leptomeningeal (n=2), both parenchymal and leptomeningeal (n=1), and pituitary gland involvement (n=1), which is an uncommon manifestation. Median duration of survival was 2.5 months after the diagnosis of CNS involvement. CONCLUSION: The incidence of secondary CNS involvement was 4.4% at initial diagnosis and 5.4% among patients with relapse of lymphoma in our study. PET/CT is a sensitive, objective, and valuable method for the diagnosis of secondary CNS involvement in patients with NHL. In addition, pituitary gland involvement, as a very rare manifestation of secondary CNS lymphoma, has been shown.

Clinical impact of ¹8F-FDG PET/CT in the pretreatment evaluation of patients with locally advanced cervical carcinoma.

AIM: The aim of this study was to evaluate the impact of F-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) on the pretreatment evaluation of patients with locally advanced cervical carcinoma. METHOD: Forty-seven patients with stage 2b-4a cervical carcinoma underwent F-FDG PET/CT for initial staging and pretreatment evaluation. Concomitant pelvic/abdominal MRI was performed in 38 patients. The contribution of PET/CT to treatment planning was evaluated, and the prognostic performance of PET/CT was compared with that of MRI. Lymph node (LN) status on PET/CT was correlated with patient follow-up data. RESULTS: PET/CT detected hypermetabolic LNs in 39/47 patients. In 24/39 patients (62%), PET/CT was found to be superior to MRI. In 13/24 patients (54%), PET/CT detected para-aortic ± pelvic LNs, which were not found on MRI. PET/CT successfully detected distant metastases in 10 patients and peritonitis carcinomatosa in one patient; these patients were upstaged clinically. Overall, PET/CT has led to modifications in the extent of the radiotherapy field in 34% of patients and to major alterations in treatment plans in 23% of patients with widespread disease. The frequency of PET-positive LNs was significantly lower in patients who were alive without disease at the time of last follow-up (60%) compared with patients with persistent disease and nonsurvivors (100%, P=0.012). CONCLUSION: The presence of PET-positive LNs has prognostic significance in patients with cervical carcinoma. PET/CT has the potential to show both lymphatic and distant metastases, which results in modifications to the chemoradiotherapeutic regimen. The use of PET/CT must be included in the initial workup of patients with locally advanced cervical carcinoma.