Role of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography in evaluating breast mucosa-associated lymphoid tissue lymphoma: A case series.

Mucosa-associated lymphatic tissue (MALT) lymphoma of the breast is an extremely rare disease; its pathogenesis is not clear because of the rarity of disease, and the best diagnostic method has yet to be established. The metabolic behavior of this lymphoma is not still clear because only a few case reports are present in literature describing the possible role of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in this field. This report presents 4 cases of women with histologically proven breast MALT lymphoma who underwent 7 18F-FDG PET/CT throughout the course of disease. All patients underwent staging PET/CT showing in all cases an FDG avid lesion corresponding to breast lymphoma; 3 patients underwent 18F-FDG PET/CT also after chemotherapy. Our results suggest that breast MALT lymphomas are 18F-FDG-avid lymphomas. Positron emission tomography/computed tomography showed heterogeneous but high FDG uptake (mean maximum standardized uptake value 7.9), suggesting that it could be part of diagnostic workup and restaging process.

Incidental 18F-FDG PET/CT bilateral breast uptake due to carcinoma.

We report a case of 71-year-old female patient, previously treated with chemotherapy and surgical resection of sigmoid tract of the large bowel for adenocarcinoma (pT3N1M0), who underwent a 18F-FDG PET/CT for a suspicious hepatic lesion detected at CT scan during follow-up. 18F-FDG PET/CT showed no abnormal uptake in the liver both at 60 minutes and 120 minutes after injection but revealed a pathological uptake in two breast nodules, (one localized in upper-internal-quadrant of the right breast and the other in the upper-external-quadrant of the left breast). The patient underwent breast MRI, which confirmed the suspicious nature of both lesions; subsequently she underwent a trucut biopsy of both lesions witch demonstrated a bilateral localization of papillary carcinoma (both lesion were classified as pT1c). The patient underwent bilateral mastectomy and the final biopsy confirmed the presence of breast cancer, while bilateral sentinel nodes biopsy showed no lymph-nodes metastases.

Multicentric study on 18F-FDG-PET/CT breast incidental uptake in patients studied for non-breast malignant purposes / Estudio multicéntrico sobre la captación incidental en la mama con 18F-FDG-PET/TAC en pacientes evaluados con fines oncológicos no relacionados con la patología mamaria

Aim. Our study has aimed to establish the prevalence and pathological nature of fluorine-18-fluorodeoxyglucose (18F-FDG) breast incidental uptake (BIU) in patients studied for non-malignant breast tumours and then to compare our data obtained in three Italian nuclear medicine centres with those available in literature. Material and methods. We retrospectively evaluated 42,927 18F-FDG-PET/CT scans performed on patients studied in three Italian Nuclear Medicine Centres. All patients underwent 18F-FDG-PET/CT for oncologic purposes not related to breast disease. Results. Among 42,927 scans, a BIU was identified in 79 (0.18%) patients, 75 (95%) female and 4 (5%) male with an average age of 62 ± 17 years. Twenty-five out of 35 (71.5%) BIUs were malignant and 10/35 (28.5%) benign. Among the 25/35 incidentalomas that were malignant, 12/25 (48%) were infiltrating ductal carcinoma, 5/25 (20%) ductal carcinoma (infiltrating and in situ), 4/25 (16%) lobular carcinoma, 2/25 (8%) ductal carcinoma in situ and 2/25 (8%) were metastases from the primary tumour under investigation. Of the 10 BIUs that were benign in the histological examination, after further investigations it was found that 9/10 (90%) were fibroadenomas and 1/10 (10%) was a benign lesion not better specified. The lesion to liver or to blood-pool SUVmax ratio in malignant lesions is significantly higher than in benign ones. Conclusions. Our multicenter study demonstrates that, although they are uncommon, BIUs show a high percentage of malignancy and therefore requires further research (AU)

Objetivo. Objetivo de nuestro estudio fue establecer la prevalencia y el carácter patológico de la captación incidental en la mama (CIM) de 18F-FDG en pacientes evaluados para tumores malignos de origen no-mamario y luego comparar nuestros datos obtenido en tres centros Italianos de Medicina Nuclear con los que están disponibles en literatura. Material y métodos. Hemos evaluado retrospectivamente 42.927 estudios 18F-FDG-PET/TAC de pacientes en tres centros Italianos de Medicina Nuclear; todos los pacientes se han sometidos a una exploración 18F-FDG-PET/TAC por fines oncológicos no relacionados con la patología mamaria. Resultados. Entre 42.927 exploraciones, una CIM fue identificada en 79 (0.18%) pacientes, 75 (95%) mujeres y 4 (5%) hombres, con una edad media de 62 ± 17 años. Veinticinco de 35 (71.5%) CIM fueron malignas y 10/35 (28.5%) benignas. Entre los incidentalomas malignos, 12/25 (48%) eran carcinomas ductales infiltrantes, 5/25 (20%) carcinomas ductales (infiltrantes e in situ), 4/25 (16%) carcinomas lobulares, 2/25 (8%) carcinomas ductales in situ y 2/25 (8%) eran metástasis de tumour primario objeto de investigación. Entre 10 CIM que fueron identificados como benignos en el examen histológico después de investigación adicional, 9/10 (90%) fueron fibroadenomas y 1/10 (10%) fue una lesión benigna no mejor especificada. El ratio del SUVmáx de la lesión en comparación con el hígado o con el pool vascular es significativamente mayor en las lesiones malignas que en las benignas. Conclusiones. Nuestro estudio multicéntrico demuestra que, aunque son poco frecuentes, las CIM muestran un alto porcentaje de malignidad, por lo tanto las CIM necesitan investigación adicional (AU)

Multicentric study on ¹8F-FDG-PET/CT breast incidental uptake in patients studied for non-breast malignant purposes.

AIM: Our study has aimed to establish the prevalence and pathological nature of fluorine-18-fluorodeoxyglucose ((18)F-FDG) breast incidental uptake (BIU) in patients studied for non-malignant breast tumours and then to compare our data obtained in three Italian nuclear medicine centres with those available in literature. MATERIAL AND METHODS: We retrospectively evaluated 42,927 (18)F-FDG-PET/CT scans performed on patients studied in three Italian Nuclear Medicine Centres. All patients underwent (18)F-FDG-PET/CT for oncologic purposes not related to breast disease. RESULTS: Among 42,927 scans, a BIU was identified in 79 (0.18%) patients, 75 (95%) female and 4 (5%) male with an average age of 62 ± 17 years. Twenty-five out of 35 (71.5%) BIUs were malignant and 10/35 (28.5%) benign. Among the 25/35 incidentalomas that were malignant, 12/25 (48%) were infiltrating ductal carcinoma, 5/25 (20%) ductal carcinoma (infiltrating and in situ), 4/25 (16%) lobular carcinoma, 2/25 (8%) ductal carcinoma in situ and 2/25 (8%) were metastases from the primary tumour under investigation. Of the 10 BIUs that were benign in the histological examination, after further investigations it was found that 9/10 (90%) were fibroadenomas and 1/10 (10%) was a benign lesion not better specified. The lesion to liver or to blood-pool SUVmax ratio in malignant lesions is significantly higher than in benign ones. CONCLUSIONS: Our multicenter study demonstrates that, although they are uncommon, BIUs show a high percentage of malignancy and therefore requires further research.

Prevalence and clinical significance of incidental F18-FDG breast uptake: a systematic review and meta-analysis.

This review aims to analyse the published data on the prevalence and clinical significance of breast incidental F18-FDG uptake detected by PET or PET/CT (BIU). A comprehensive computer literature search of the PubMed/MEDLINE, Scopus and Embase databases for studies on BIU published through July 2013 was performed. Pooled prevalence and malignancy risk of BIU were calculated. The literature search revealed 42 articles, and 17 were selected. One study was excluded because of data overlap but four additional studies were found screening the references. Finally, 20 articles were included in the systematic review and 13 were eligible for a meta-analysis. The pooled prevalence of BIU on all scans was 0.4 % (95 % CI 0.23-0.61 %), the pooled prevalence on scans on female patients only was 0.82 % (95 % CI 0.51-1.2 %), the pooled risk of malignancy of BIU when further analysed was 48 % (95 % CI 38-58 %) and the pooled risk of malignancy of BIU with histological examination was 60 % (95 % CI 53-66 %). The most frequent malignant lesion detected was infiltrating ductal carcinoma. Despite being rare, the identification of BIU frequently signals the presence of an unsuspected subclinical lesion, which differs from the indicated reason for which the patient was initially scanned, and the risk of malignancy is very high.

Primary breast non-Hodgkin lymphoma. A report of an unusual case.

Although lymphomas are generally considered as tumors of lymph nodes about 25-40% arise at extranodal sites. We report a case of a 60 years old female who developed a right breast B-diffuse large cell non-Hodgkin lymphoma in 2005 treated by chemo/radio-therapy which relapsed at the same breast in 2007 and at the other breast in 2010. The patient underwent both radiologic and nuclear medicine studies.

Which is the best MRI marker of malignancy for atypical cirrhotic nodules: hypointensity in hepatobiliary phase alone or combined with other features? Classification after Gd-EOB-DTPA administration.

PURPOSE: To investigate whether the malignancy of atypical nodules in cirrhosis can be identified at gadoxetic-acid-disodium(Gd-EOB-DTPA)-MRI by their hypointensity in the hepatobiliary(HB)-phase alone or combined with any other MR imaging features. MATERIALS AND METHODS: One hundred eleven atypical nodules detected in 77 consecutive Gd-EOB-DTPA-MRIs were divided, based on arterial-phase behavior, into: Class I, isovascular (n = 82), and Class II, hypervascular without portal/delayed washout (n = 29). The two classes were further grouped based on HB-phase intensity (A/B/C hypo/iso/hyperintensity). Portal/venous/equilibrium-phase behavior and T2w features were also collected. Histology was the gold standard. Per-nodule sensitivity, specificity, negative and positive predictive values (NPV/PPV), and diagnostic accuracy were calculated for HB-phase hypointensity alone, and combined with vascular patterns and T2w hyperintensity. RESULTS: Histology detected 60 benign and 51 malignant/premalignant nodules [10 overt hepatocellular carcinomas (HCCs) and 41 high-grade dysplastic nodules (HGDN)/early HCC]. Class IA contained 31 (94%) malignancies, IB one (3%), and IC only benign lesions. Class IIA had 100% malignancies, IIB three (37.5%) and IIC only two (28.5%). HB-phase hypointensity alone (Classes I-IIA) had 88% sensitivity, 91% NPV, and 93% diagnostic accuracy, superior (P < 0.05, P < 0.006, and P < 0.05, respectively) to any other MR imaging feature alone or combined. CONCLUSION: In atypical cirrhotic nodules, HB-phase hypointensity by itself is the strongest marker of malignancy.

Role of ¹¹C-choline positron emission tomography/computed tomography in evaluating patients affected by prostate cancer with suspected relapse due to prostate-specific antigen elevation.

PURPOSE: The aim of this study was to evaluate the accuracy of (11)C-choline positron emission tomography/computed tomography (PET/CT) in restaging patients affected by prostate cancer and suspected relapse due to prostate-specific antigen (PSA) increase. We also aimed to determine a PSA cutoff that is most suited to the study in terms of best compromise between sensitivity and specificity. Secondary endpoints were a comparison between (11)C-choline PET/CT and histological results, clinical findings, and radiological imaging (CT and magnetic resonance imaging). MATERIALS AND METHODS: We retrospectively evaluated 210 patients (median ± SD age 70 ± 7 years) affected by prostate cancer who underwent (11)C-choline PET/CT. RESULTS: (11)C-choline PET/CT imaging was positive in 116 (55.2%) patients and negative in 94 (44.8%). Receiver operating characteristic (ROC) analysis showed that the highest accuracy (sensitivity 76.8%, specificity 92.5%) for the whole population was achieved when the PSA level of 1.26 ng/ml level was used as the cutoff value for interpreting the results (P = 0.0001 and the area under the ROC curve AUC 0.897). For patients treated with surgery or surgery plus radiotherapy the cutoff was 0.81 ng/ml (sensitivity 73.2%, specificity 86.1%). For patients treated with radiotherapy alone, the cutoff was 2.0 ng/ml (sensitivity 81.8%, specificity 92.9%). CONCLUSION: Our results indicate that (11)C-choline PET/CT is a useful diagnostic tool in patients affected by prostate cancer and a relapsed PSA level. The highest accuracy for all patients is obtained with a PSA cutoff level of 1.26 ng/ml, above which the imaging study is performed (0.81 ng/ml for patients treated with surgery or surgery plus radiotherapy and 2.0 ng/ml for patients treated with radiotherapy alone).

Role of ¹8F-fluorodeoxyglucose positron emission tomography/computed tomography in patients affected by differentiated thyroid carcinoma, high thyroglobulin level, and negative ¹³¹I scan: review of the literature.

Differentiated thyroid carcinoma (DTC) is a slow-growing tumor that represents 1% of all malignant tumors and is the most frequent endocrine cancer. ¹8F-Fluorodeoxyglucose positron emission tomography/computed tomography (¹8F-FDG-PET/CT) imaging is an increasingly important imaging tool in oncology and is still under investigation in numerous studies looking into its efficacy and cost-effectiveness. Despite the fact that ¹8F-FDG-PET/CT has been shown to be a powerful and accurate diagnostic tool in patients affected by DTC with high serum thyroglobulin (Tg) levels and negative radioiodine (¹³¹I) total body scan, its definitive role is not completely clear, in particular regarding the role of thyroid stimulating hormone (TSH) and Tg value "cutoff" over which is better to perform the study. In this review, these issues are analyzed to clarify controversial aspects and identify established cornerstones. In particular, the literature analysis suggests that levothyroxine withdrawal is preferable in cases of relatively low Tg levels (<10 ng/ml) and good clinical compliance to hypothyroidism. Moreover, recombinant thyrotropin stimulating hormone (rTSH) could be a preferable alternative in patients clinically unable to tolerate therapy withdrawal. A Tg cutoff level over which to perform the study seems to be 10 ng/ml, a reasonable value maintaining high accuracy in terms of a good compromise between sensitivity and specificity.

Role of F-18-FDG-PET/CT in restaging of patients affected by gastrointestinal stromal tumours (GIST).

BACKGROUND: Gastrointestinal stromal tumours (GISTs) are a subset of mesenchymal tumours that represent the most common mesenchymal neoplasms of the gastrointestinal (GI) tract and account for less than 1% of all gastrointestinal tumours. MATERIAL AND METHODS: We retrospectively evaluated 19 patients (6 females and 13 males; median age: 61 years ± 15 standard deviation) affected by GIST histologically documented after surgical intervention or biopsy. RESULTS: F18-FDG-PET/CT had identified pathologic uptakes and was considered positive for neoplastic tissue in 10 patients (53%) and negative in 9 (47%), in concordance with radiological findings. CONCLUSIONS: F18-FDG-PET/CT is a feasible, reliable, and accurate method to restage patients affected by previously histologically confirmed GIST, also in the absence of a staging study.