Hounsfield unit value has null effect on thyroid nodules at 18F-FDG PET/CT scans.

OBJECTIVES: Detection rate of thyroid nodules is increasing with the use of new imaging modalities, especially in screening for malignancies. Positron emission tomography/computed tomography (PET/ CT)-positive thyroid nodules should be differentiated for malignancy to avoid unnecessary operations and further follow-up. Most trials evaluate the role of SUVmax, but there is no definitive information about the utility of Hounsfield unit (HU) values for prediction of malignancy. This study aimed to evaluate the HU values beside SUVmax for detecting malignancy risk of PET/CT-positive thyroid nodules. SUBJECTS AND METHODS: Results of 98 cancer patients who had fine needle aspiration biopsy (FNAB) for thyroid nodules detected on PET/CT between January 2011 and December 2015 were assessed. The FNABs and surgical pathological results were recorded. RESULTS: FNABs revealed benign results in 32 patients (32.7%), malignant in 18 (18.4%), non-diagnostic in 20 (20.4%), and indeterminate in 28 (28.5%). Twenty-four patients underwent thyroidectomy. The mean HU values were not significantly different in benign and malignant nodules (p = 0.73). However, the mean SUVmax was significantly higher (p < 0.001) in malignant ones. Area under curve (AUC) was 0.824 for SUVmax; the cut-off value was over 5.55 (p < 0.001), with 80% sensitivity, 84.5% specificity. CONCLUSIONS: Our current study demonstrated that HU value does not add any additional valuable information for discriminating between malignant and benign thyroid nodules. We also defined a SUV cut-off value of 5.55 for malignant potential of thyroid nodules detected on PET/CT Arch Endocrinol Metab. 2018;62(4):460-5.

Hounsfield unit value has null effect on thyroid nodules at 18F-FDG PET/CT scans

ABSTRACT Objectives: Detection rate of thyroid nodules is increasing with the use of new imaging modalities, especially in screening for malignancies. Positron emission tomography/computed tomography (PET/ CT)-positive thyroid nodules should be differentiated for malignancy to avoid unnecessary operations and further follow-up. Most trials evaluate the role of SUVmax, but there is no definitive information about the utility of Hounsfield unit (HU) values for prediction of malignancy. This study aimed to evaluate the HU values beside SUVmax for detecting malignancy risk of PET/CT-positive thyroid nodules. Subjects and methods: Results of 98 cancer patients who had fine needle aspiration biopsy (FNAB) for thyroid nodules detected on PET/CT between January 2011 and December 2015 were assessed. The FNABs and surgical pathological results were recorded. Results: FNABs revealed benign results in 32 patients (32.7%), malignant in 18 (18.4%), non-diagnostic in 20 (20.4%), and indeterminate in 28 (28.5%). Twenty-four patients underwent thyroidectomy. The mean HU values were not significantly different in benign and malignant nodules (p = 0.73). However, the mean SUVmax was significantly higher (p < 0.001) in malignant ones. Area under curve (AUC) was 0.824 for SUVmax; the cut-off value was over 5.55 (p < 0.001), with 80% sensitivity, 84.5% specificity. Conclusions: Our current study demonstrated that HU value does not add any additional valuable information for discriminating between malignant and benign thyroid nodules. We also defined a SUV cut-off value of 5.55 for malignant potential of thyroid nodules detected on PET/CT Arch Endocrinol Metab. 2018;62(4):460-5

A different cause for respiratory disorder in children: cases with pulmonary Langerhans cell histiocytosis.

BACKGROUND AND AIMS: In children, complaints of a respiratory disorder are very frequent. Etiology of respiratory illness is a broad spectrum that varies from a simple viral infection to a malignant disorder. Pulmonary Langerhans cell histiocytosis (PLCH) is one of these entities and it is truly rare in children. The aim of this study is to evaluate our patients with PLCH. METHODS: Patients who had been diagnosed with PLCH were retrospectively evaluated. Features of medical history, onset of the complaints, date of the diagnosis, chest X-Ray and computed tomography (CT) findings, histopathology and other laboratory investigations were considered. RESULTS: There were four cases with PLCH. All of them were male, ages were between 5 months and 16 years. In three cases, major complaints were chronic respiratory problems whereas in one of them there was acute respiratory distress beginning with cough and leading to pneumothorax. In all of the cases, multisystemic involvement was prominent. The diagnosis was proven by histopathology in all of the cases. In two children with smaller age, skin involvement was detected. Time from complaint to diagnosis was minimum 3 months and maximum 3 years. CONCLUSION: PLCH is a rare disorder in children. Pulmonary involvement is generally a component of systemic involvement but in many cases it might have been detected with early respiratory complaints. So, children with chronic respiratory problems should be carefully evaluated and should be followed up for rare entities like PLCH.

An old enemy not to be forgotten during PET CT scanning of cancer patients: tuberculosis.

AIM OF THE STUDY: Positron emission tomography-computed tomography (PET CT) scan is commonly used in current medical oncology practice as an imaging method. In this study we present data from cancer patients who were followed at our clinic and suspected of having tuberculosis during PET CT scanning. After the biopsy, they were diagnosed with concomitant tuberculosis. MATERIAL AND METHODS: In this study, 14 patients who applied to our clinic and followed up due to cancer, and had PET CT scanning for the preliminary staging or further evaluation, were included. The patients were diagnosed with metastatic or recurrent disease, and their biopsy results revealed tuberculosis. RESULTS: The mean age was 57.8 years with SD (standard deviation) 13.1 years and gender distribution of 78.6% (n = 11) females and 21.4% (n = 3) males. None of the patients had tuberculosis in their personal history (0%). Among the patients, 5 (35.7%) were diagnosed with tuberculosis during the preliminary staging, whereas 9 (64.3%) were diagnosed during the follow-up after the treatment. The median time to tuberculosis diagnosis was 11 months (min-max: 3-24 months) after the treatment. The most commonly involved lymph nodes during PET CT scanning were mediastinal in 8 (64.3%), axillary in 3 (21.4%) and para-aortic in 3 (21.4%) patients. The mean SUVmax (maximum standardised uptake value) of lymph node involved by PET CT scanning was defined as 8.5 (SD 2.6). CONCLUSIONS: Despite all improvements in modern medicine, tuberculosis is still a serious public health problem. It should always be considered in differential diagnosis while evaluating PET CT scanning results of cancer patients, because it may cause false positive results.

Castleman's disease mimicking right adrenal neoplasm: a case report.

Castleman's disease usually manifests as a solitary mediastinal tumor and only rarely as an isolated retroperitoneal mass. This disorder is often undiagnosed or misdiagnosed. Thus, only very few patients have been reported and little information is available in the literature. The definitive diagnosis is based on postoperative pathological findings. We report a case of a 57-year-old female with a Castleman's tumor located superomedial to the upper pole of the right kidney that mimicked an adrenal neoplasm. The mass was surgically resected, and the histopathological diagnosis of the resected tissue was hyaline-vascular type of Castleman's disease. Although retroperitoneal Castleman's disease is rare, it should be considered in the differential diagnosis of retroperitoneal masses.

Primary renal lymphoma: report of four cases.

BACKGROUND: Although secondary renal involvement from systemic lymphoma is very frequent, primary renal lymphoma is a rare entity. It is characterized by aggressive histopathology, very early extra-renal infiltration and poor prognosis. CASE REPORTS: Here, we report 4 cases of primary renal lymphoma presenting with unilateral renal masses, which after radiological and clinical examination were assumed to be renal cell carcinoma. 3 patients were diagnosed with Non-Hodgkin's lymphoma by nephrectomy and one patient was diagnosed by open renal biopsy. Histopathological subtypes were diffuse large B cell lymphoma in 2 cases and non-Hodgkin's lymphoma of small B cell type in the others. While 3 of the patients were treated with systemic chemotherapy, the fourth patient refused chemotherapy. 2 patients (no. 2 and 3) were still in complete remission and were followed regularly in the second and first year after diagnosis, respectively. CONCLUSIONS: Since it is difficult to diagnose primary renal lymphoma, most patients with this kind of tumor undergo radical nephrectomy, and diagnosis of primary renal lymphoma is delayed. The authors believe that both the delayed diagnosis due to anatomical difficulties and the histological aggressive characteristics of this disease are equally responsible for the poor outcome in the case of primary renal lymphoma.

Intranasal porous polyethylene implant extrusion 7 years after insertion in a patient with Hashimoto disease.

We report a case of intranasal porous polyethylene implant extrusion 7 years after insertion in a patient with Hashimoto disease. We also discuss the possible causes of the extrusion and convey the histopathologic examination and microbiological investigation results of the samples taken from the removed implant.

The role of tissue reperfusion in the reexpansion injury of the lungs.

OBJECTIVE: The aim was to discuss the balance between free radical damage and body defense mechanisms that occurred in reexpansed pulmonary tissue and to evaluate the relationship between the changes in the pulmonary circulation and the mentioned balance. METHODS: Twenty male Wistar Albino rats were used for these study results. Pneumothorax was created in the left hemithorax by percutaneous route in all the rats. After 7 days, the first group (n = 10) had a sternotomy under ketamine anesthesia. Following invasive measurement of pulmonary artery pressure, tissue samples were obtained from the lower lobes of the right and left lungs before reexpansion occurred. Tracheotomies were opened in the second group (n = 10) with a 16 gauge cannula. Following sternotomy, invasive mean pulmonary artery pressure measurements were obtained by the support of non-invasive cardiac monitorization. The lungs were aerated with 4 cmH(2)O oxygen and fixed volume support and 1 h of reexpansion was obtained. Invasive mean pulmonary artery pressure measurements were repeated after reexpansion and tissue samples were obtained from the lower lobes of left and right lungs. Nitric oxide (NO), malondialdehyde (MDA) and superoxide dismutase (SOD) levels were measured in tissue samples, surfactant staining and light microscopic evaluations were performed. RESULTS: At the end of the reexpansion, there was a decrease in mean pulmonary artery pressure (P < 0.01), MDA (P < 0.01) and SOD (P < 0.05) levels and an increase in NO (P < 0.05) levels. Under the light microscopic examination, in the samples that were provided with reexpansion, the alveolo-capillary membrane was thickened due to increasing edema, increase in the number of lymphocytes and return of the neutrophil leukocytes to the area. There was no significant difference between the groups in terms of surfactant staining. CONCLUSION: The tissue reperfusion that is achieved with the restoration of blood flow during the reexpansion of collapsed lungs, can be the initial pathology in the chain of events that result in reexpansion injury.