Localized subacute thyroiditis presenting as a painful hot nodule.

BACKGROUND: A diagnosis of subacute thyroiditis is readily considered when patients present with a particular set of typical clinical characteristics. Subacute thyroiditis sometimes presents as a solitary cold nodule; however, the presence of a hot nodule in patients with subacute thyroiditis is exceedingly rare. CASE PRESENTATION: Here, the case of a 57-year-old woman complaining of pain in the left neck and fatigue for two weeks is presented. Physical examination revealed a painful and tender nodule with a diameter of approximately 1.5 cm in the left neck, although all laboratory tests, including white blood cell count, neutrophil percentage, erythrocyte sedimentation rate (ESR), thyroid function, and thyroglobin levels, were normal. A neck ultrasound revealed a hypoechoic mass (1.5 × 0.8 cm) in the left thyroid, and thyroid scintigraphy of the left thyroid with Technetium-99 m (99 m-Tc) demonstrated a focal accumulation of radiotracer. Furthermore, fine-needle aspiration biopsy from the nodule revealed the presence of multinuclear giant cells. The patient was well; there was no cervical mass detected upon palpation following two months of prednisone treatment, and follow-up ultrasound screening and scintigraphy demonstrated the disappearance of the nodule. CONCLUSION: This case, presenting with a localized painful hot nodule, normal thyroid function, normal ESR, and normal serum thyroglobulin levels, is a rare case of subacute thyroiditis, which should be considered during differential diagnosis.

111In-labeled cystine-knot peptides based on the Agouti-related protein for targeting tumor angiogenesis.

Agouti-related protein (AgRP) is a 4-kDa cystine-knot peptide of human origin with four disulfide bonds and four solvent-exposed loops. The cell adhesion receptor integrin α(v)ß(3) is an important tumor angiogenesis factor that determines the invasiveness and metastatic ability of many malignant tumors. AgRP mutants have been engineered to bind to integrin α(v)ß(3) with high affinity and specificity using directed evolution. Here, AgRP mutants 7C and 6E were radiolabeled with (111)In and evaluated for in vivo targeting of tumor integrin α(v)ß(3) receptors. AgRP peptides were conjugated to the metal chelator 1, 4, 7, 10-tetra-azacyclododecane- N, N', N″, N'''-tetraacetic acid (DOTA) and radiolabeled with (111)In. The stability of the radiopeptides (111)In-DOTA-AgRP-7C and (111)In-DOTA-AgRP-6E was tested in phosphate-buffered saline (PBS) and mouse serum, respectively. Cell uptake assays of the radiolabeled peptides were performed in U87MG cell lines. Biodistribution studies were performed to evaluate the in vivo performance of the two resulting probes using mice bearing integrin-expressing U87MG xenograft tumors. Both AgRP peptides were easily labeled with (111)In in high yield and radiochemical purity (>99%). The two probes exhibited high stability in phosphate-buffered saline and mouse serum. Compared with (111)In-DOTA-AgRP-6E, (111)In-DOTA-AgRP-7C showed increased U87MG tumor uptake and longer tumor retention (5.74 ± 1.60 and 1.29 ± 0.02%ID/g at 0.5 and 24 h, resp.), which was consistent with measurements of cell uptake. Moreover, the tumor uptake of (111)In-DOTA-AgRP-7C was specifically inhibited by coinjection with an excess of the integrin-binding peptidomimetic c(RGDyK). Thus, (111)In-DOTA-AgRP-7C is a promising probe for targeting integrin α(v)ß(3) positive tumors in living subjects.

Imaging proliferation in human leukemia-tumor bearing mice with (18)F-FLT: Comparison with (18)F-FDG PET.

Leukemia threatens human life due to its uncontrolled proliferative malignancy. 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) has been suggested as a new positron emission tomography (PET) tracer for imaging tumor proliferation. The aim of the study was to investigate the usefulness of (18)F-FLT PET for imaging human leukemia-tumor bearing mice, compared with fluorine-18-fluorodesoxyglucose ((18)F-FDG PET). In vitro the experiments of (18)F-FLT and (18)F-FDG uptake were performed in K562 cell lines at various time points and radioactive tracer uptake was measured in a gamma counter. (18)F-FLT and (18)F-FDG PET imaging were performed both in the same mouse when eight tumor-bearing mice models of human chronic myeloid leukemia were established successfully by injecting K562 cells. Regions of interest were drawn over the tumor, the crossed normal tissue was regarded as background and the ratio of tumor to non-tumor counts (T/NT) in tissues was calculated. A higher uptake of (18)F-FLT (15min, 5.73±0.05%; 30min, 5.90±0.06%; 60min, 6.16±0.19%; 120min, 6.32±0.08%) than that of (18)F-FDG (15min, 1.05±0.10%; 30min, 1.11±0.14%; 60min, 1.14±0.37%; 120 min, 1.36±0.25%) was observed in K562 cells in the tracer uptake experiment. Ratios of T/NT of (18)F-FLT PET (0.5h, 5.39±0.42; 1h, 4.88±0.43; 2h, 3.81±0.38) were higher than those of (18)F-FDG PET/CT (0.5h, 0.34±0.12; 1h, 0.21±0.06; 2h, 0.13±0.05) after injection. Both uptake and T/NT differences of (18)F-FLT versus (18)F-FDG were significant (P>0.05). In conclusion, (18)F-FLT and (18)F-FDG quantitative and semi-quantitative uptake measurements resulting from cell lines and PET imaging respectively suggested a promising potential of (18)F-FLT for metabolic imaging of human chronic myeloid leukemia.

A first described chest wall metastasis from colon cancer demonstrated with (18)F-FDG PET/CT.

It is well known that, haematogenous colon cancer metastases are most commonly found in the liver, less likely in the lungs through the paravertebral venous system and rarely in other organs. Sporadic clinical cases of colon cancer metastases to the abdominal wall, the thyroid or the adrenal glands have been reported. Here, we present an uncommon case of chest wall metastasis from colon cancer demonstrated with 2-fluoro [fluorine-18]-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography/computed tomography (PET/CT). A 52 years old female patient was examined after she felt a swelling mass above her left breast. Tumor makers, such as serum cancer embryonic antigen (CEA) 146.22kU/L (normal range:0.00~37.0kU/L) and CA19-9 (258.16µg/L (normal range:0.00~10.0µg/L) and neuron-specific enolase (NSE) 78.2 (normal range: 0.00~17.00) were abnormally high. Chest CT revealed the soft tissue density mass on the left anterior chest wall with invasion of left 4th rib, and CT-guided biopsy showed a poorly differentiated adenocarcinoma of unkown origin. The patient was then referred for the (18)F-FDG-PET scan which was performed one hour after the intravenous injection of 370MBq of (18)F-FDG (Discovery Camera, VCT, GE, USA) and showed in addition to the chest mass, abnormal (18)F-FDG accumulation in both lungs, left supraclavicular and peritoneal lymph nodes. Furthermore, high (18)F-FDG uptake was detected in the sigmoid. Pathology findings from colonoscopy confirmed that this was a sigmoid colon adenocarcinoma. So far, chest wall metastasis from colon cancer as an initial finding has not been reported. Usually, an initial chest wall mass is hardly suspected to be a colon cancer metastasis. Abnormal serum tumor markers such as CEA and CA19-9 supported the diagnosis of a gastrointestinal adenocarcinoma. In our case, we found high serum NSE and normal findings of bowel wall on the CT scan, thus without the positive (18)F-FDG findings, one would probably consider as first diagnosis: chest wall metastasis from lung cancer, or a neuroendocrine tumor. The unusual finding in this case was that on the CT images there was no obvious local density of the intestine, no bowel wall thickening, or suspicious nodular lesions. Segmental (18)F-FDG accumulation seen in the sigmoid colon had early maximum standardized uptake value (SUV(max)) 7.3 and in 1h delayed estimation, 8.1. Colonoscopy showed that the (18)F-FDG-avid area at the colon was circular and thickened. "Hot" lesions found in both lungs, the supraclavicular and retroperitoneal lymph nodes by (18)F-FDG PET/CT scan were considered to be most probably metastases from colon adenocarcinoma. In conclusion, PET as a rather simple procedure and less dependent on bowel preparation diagnosed the primary colon cancer, its metastases and specifically a first described chest wall metastasis, while CT alone did not show the primary tumor.

Clinical usefulness of single photon emission tomography/computed tomography with stress analysis in early diagnoses of stem instability of noncemented hip arthroplasty.

OBJECTIVE: Hip pain arising from implant instability is generally caused by repetitive stress injury, which subsequently leads to induction or exacerbation of abnormal metabolism of bone around the implant. single photon emission tomography/computed tomography (SPECT-CT) has advantages in localizing areas of increased tracer uptake that reflects such abnormal bone metabolism. Therefore, we investigated whether the application of SPECT/CT with stress analysis can be an effective practice in evaluating the instability of stem in noncemented hip arthroplasty or not. METHOD: In total 16 patients were collected for unexplained painful hip arthroplasties. When physical examination and blood tests were unremarkable, radiographs were inconclusive and bone scan indicated increased scintigraphic uptake at the proximal part and at the tip of the stem; SPECT/CT was performed. Stem stability was assessed by measuring whether there was consistency between the increased scintigraphic uptake and the direction of the stress around the implant along with the location of the prosthesis. RESULT: Among the 16 symptomatic hips, 9 hips showed the stability of the stem, 3 hips showed the stem instability and 4 hips showed the acetabular loosening with the stem stability. With the application of SPECT/CT with stress analysis, 15 out of 16 (93.7%) cases were found to have the change in the diagnoses, and managements were implemented in 11 out of 16 (68.7%) cases. When comparing before and after SPECT/CT, there was no significant association in clinical diagnosis and management (Pearson chi- square test = 4.61 and 1.33, P = 0.33 and 0.25). CONCLUSION: SPECT/CT combined with stress analysis can be a useful tool in early diagnosis of stem instability and can assist surgeons in subsequent management and decision implementation when other radiographic imagings are inconclusive.

Bone turnover markers in patients with differentiated thyroid carcinoma after levothyroxine withdrawal.

BACKGROUND: Patients receiving postoperative radioiodine therapy for advanced differentiated thyroid carcinoma (DTC) are repeatedly in short-term thyroid hormone deficiency, whose bone turnover state is not fully understood. METHODS: Serum bone turnover markers (BTMs), bone specific alkaline phosphatase (BALP), type 1 procollagen N-terminal propeptide (P1NP), osteocalcin (OC), and the beta-isomerized C-terminal telopeptide of type 1 collagen (beta-CTx) were measured in 50 adult male DTC patients after 4-week suspension of levothyroxine replacement therapy and 40 matched euthyroid controls. Relationships between parameters of thyroid function (free triiodothyronine, FT3; free thyroxine, FT4; thyroid stimulating hormone, TSH) and the BTMs were studied. RESULTS: The patients had significantly decreased OC (-37.6%, P<0.001) and beta-CTx (-35.5%, P<0.001) compared with the controls, showing FT3 as the independent risk factor for OC (R2=0.425, P<0.001) and beta-CTx (R2=0.124, P<0.001). Partial correlation analysis showed that only FT3 was significantly correlated with OC after controlling FT4 and TSH (r=0.362, P=0.001). CONCLUSIONS: DTC patients have moderately decreased bone turnover after short-term suspension of thyroxine suppressive therapy, with serum FT3 concentration as the predominant and independent risk factor.

Outcome after high-dose radioiodine therapy for advanced differentiated thyroid carcinoma in childhood.

OBJECTIVE: To evaluate the clinical outcome in childhood patients receiving postoperative high-dose radioiodine therapy for advanced differentiated thyroid carcinoma. METHOD: Patients under 18 years old with neck diseases (n = 4) or distant metastases (n = 10) received postoperative radioiodine ablation and repeated treatments for a median of 2 (0.8 10) years with an averaged activity of 25.0 (7.0 72.2) GBq. RESULTS: Partial remission was achieved in 6, stable disease in 6 and progressive disease in 2 patients, without severe side effects except for two Grade 1 and one Grade 2 WHO haematological toxicity. The median survival time from diagnosis to the last treatment sessions was 5.3 (range, 0.7 14.5) years. CONCLUSION: High-dose radioiodine treatment was well tolerated with satisfactory outcome in childhood patients with advanced differentiated thyroid carcinoma.

Preparation and bioevaluation of (99m)Tc-HYNIC-annexin B1 as a novel radioligand for apoptosis imaging.

Annexin B1, a novel Ca2+-dependent PS-binding protein, has been shown to have a high affinity for PS exposed on the surface of apoptotic cells. To develop and bioevaluate an annexin B1 based PS-targeting radiotracer, annexin B1 was radiolabeled with (99m)Tc using HYNIC as a bifunctional chelator. Binding assays with activated platelets and apoptotic SP2/0 cells were carried out to evaluate the in vitro biological activity of (99m)Tc-HYNIC-annexin B1. Biodistribution of this radioligand was studied in normal mice. Dexamethasone-induced murine thymus apoptosis and fas-mediated murine liver apoptosis models were used to investigate the ability of radiolabeled annexin B1 to detect apoptosis in vivo. The labeling procedure yielded a compound with up to 98% radiochemical purity and good in vitro stability. The in vitro binding assays indicated that (99m)Tc-HYNIC-annexin B1 retain its PS-binding activity. Biodistribution of the compound in mice showed that (99m)Tc-HYNIC-annexin B1 is rapidly cleared from the blood and predominantly accumulates in the kidney. The marked increase in dexamethasone-treated murine thymus uptake and fas-mediated murine liver uptake correlated with histologic evidence of apoptosis. These data suggested that (99m)Tc-HYNIC-annexin B1 retain its in vitro and in vivo biological activities. This radiotracer may therefore be useful as a novel radioligand for the noninvasive detecting of PS externalization associated with apoptosis.

Incremental value of 131I SPECT/CT in the management of patients with differentiated thyroid carcinoma.

UNLABELLED: (131)I whole-body scintigraphy (WBS) is a highly sensitive method for the detection of differentiated thyroid tumors and metastases. However, a lack of anatomic landmarks and the physiologic accumulation of the tracer complicate interpretation of the images. This prospective study was designed to evaluate the incremental value of (131)I SPECT/CT over planar WBS in the management of patients with differentiated thyroid carcinoma (DTC). METHODS: Planar imaging was performed on 66 consecutive DTC patients who were considered to have locally advanced or metastatic disease after total or nearly total thyroidectomy. SPECT/CT was added for patients whose planar findings were inconclusive. The planar images were interpreted by 2 experienced nuclear medicine physicians. Interpretation of the SPECT/CT images was a consensus opinion of one of the nuclear medicine physicians and an experienced radiologist. Fusion images were considered to improve image interpretation when they better localized sites of increased (131)I uptake. The final diagnosis was verified by pathologic findings, other imaging modalities, and clinical follow-up. Both site-based and patient-based analyses were performed, and the impact of SPECT/CT results on therapeutic strategy was assessed. RESULTS: A total of 232 foci were observed by (131)I WBS, including 33.2% of foci localized in the thyroid bed, 62.1% due to malignant lesions, and 4.7% caused by nonthyroidal physiologic or benign uptake or a contaminant. Overall, 37 SPECT/CT studies were performed on 23 patients, whose planar images showed 81 inconclusive lesions. Precise localization and characterization of (131)I-avid foci were achieved through (131)I SPECT/CT in 69 (85.2%) and 67 (82.7%) of the 81 foci, respectively. Fusion images were considered to be of benefit in 17 (73.9%) of 23 patients. The therapeutic strategy was changed in 8 (47.1%) of 17 patients. Uncommon metastatic lesions were found in 9 (13.6%) of 66 patients with regard to SPECT/CT fusion images. CONCLUSION: Fusion of SPECT and CT images was of incremental value over WBS in increasing diagnostic accuracy, reducing pitfalls, and modifying therapeutic strategies in 73.9% of DTC patients. As SPECT/CT techniques emerge, (131)I SPECT/CT may demonstrate higher value than WBS in the management of DTC.

Comparison of free plasma metanephrines enzyme immunoassay with (131)I-MIBG scan in diagnosis of pheochromocytoma.

Measurement of free plasma metanephrines (metanephrine and normetanephrine), usually performed by high-performance liquid chromatography with electrochemical detection (HPLC-ECD), has been recommended as the single biochemical test of choice for the diagnosis of pheochromocytoma. Alternatively, a widely available, simple means to measure these biomarkers with enzyme immunoassay (EIA) needs to be studied. The aim of this study was to investigate the diagnostic efficacy of such a method in comparison with (131)I-metaiodobenzylguanidine (MIBG) whole body scan (WBS) in patients with pheochromocytoma. We enrolled patients undergoing (131)I-MIBG WBS due to clinical findings suggestive of pheochromocytoma (n = 45), and patients with primary hypertension (n = 36). All subjects had blood tests for free plasma metanephrine (MN) and normetanephrine (NM) with a commercially available EIA kit. WBS was positive in 30 pheochromocytoma patients and negative in 15 refuted ones, with 100% accuracy. The sensitivity, specificity and accuracy of MN and NM in combination (either or both positive) were 96.7%, 86.3% and 90.1%, showing comparable diagnostic performance both to (131)I-MIBG WBS (all p > 0.1), and also to the same markers measured with HPLC-ECD reported in the literature. These results showed that the EIA method may be eligible as an alternative to HPLC-ECD for plasma metanephrine determination in the identification of pheochromocytoma.

Mutual interference between serum thyroglobulin and antithyroglobulin antibody in an automated chemiluminescent immunoassay.

OBJECTIVES: To investigate the analytical interference between serum Tg and TgAb. DESIGN AND METHODS: Tg and TgAb were measured on an automated chemiluminescent immunoassay system in mixed sera from DTC patients and individual samples spiked with exogenous Tg. RESULTS: Tg and TgAb recoveries in mixed patient samples were inversely correlated with expected TgAb or Tg concentrations, respectively. Impaired TgAb recoveries were also found in 50% (10/20) samples with high Tg in the exogenous recovery tests. CONCLUSIONS: Mutual but not equal analytical interference between Tg and TgAb is present and concentration-dependent with interpatient variability.

99mTc-pertechnetate uptake in hepatoma cells due to tissue-specific human sodium iodide symporter gene expression.

UNLABELLED: The sodium iodide symporter (NIS) gene could be used as an ideal reporter gene as well as a promising therapeutic gene. 99mTc-pertechnetate has proven to be more advantageous than 131I-iodide with respect to image quality, procedure and radiation dose in examination of thyroid uptake and scintigraphy. Herein, we investigated the feasibility of monitoring human sodium iodide symporter (hNIS) gene expression with 99mTc-pertechnetate in hepatoma cells (MH3924A) following tissue-specific expression. METHODS: MH3924A cells were stably transfected with the recombinant retroviral vector, in which hNIS cDNA was driven by murine albumin enhancer/promoter (mAlb) and coupled to hygromycin resistance gene using an internal ribosomal entry site. Functional NIS expression in hepatoma cells was confirmed by an 125I(-) uptake assay. The dynamic uptake and efflux of 99mTc-pertechnetate was determined both in vitro and in vivo. RESULTS: The 99mTc-pertechnetate was up to 254-fold higher in stably transfected MH3924A cells than in wild-type cells. However, the in vitro efflux of 99mTc-pertechnetate out of recombinant cells was rapid with a half-life of less than 2 min. Further, the in vivo studies yielded clear images and quantitative data of mAlbhNIS-infected tumor xenografts using 99mTc-pertechnetate and gamma camera. CONCLUSION: The current study demonstrates enhanced 99mTc-pertechnetate uptake in hepatoma cells in vitro and in vivo following tissue-specific gene transfer using a recombinant retrovirus with the albumin enhancer/promoter and the hNIS gene. It is feasible to monitor hNIS gene expression noninvasively and quantitatively using conventional gamma camera and 99mTc-pertechnetate.

The role of radionuclide lymphoscintigraphy in extremity lymphedema.

The characteristics of lymphedema on radionuclide lymphoscintigraphy were studied, and the diagnostic value of radionuclide lymphoscintigraphy in lymphedema was evaluated. In this report radionuclide lymphoscintigraphy was performed in 110 cases of clinically suspected lymphedema. A retrospective study method was used to analyze the imaging results. The typical pattern of lymphedema on radionuclide lymphoscintigraphy was summarized. It was found that the characteristics of lymphedema on radionuclide lymphoscintigraphy were diverse. The most common pattern was increased radiotracer accumulation in the soft tissue and lymphatic webs. Surgery and infection dominated as the causes of lymphedema in this study. It was concluded that radionuclide lymphoscintigraphy is a useful noninvasive method for diagnosing lymphedema. It is easy to operate and provides reliable results.

Short-Term Side Effects after Radioiodine Treatment in Patients with Differentiated Thyroid Cancer.

OBJECTIVES: I-131 therapy for differentiated thyroid cancer (DTC) could induce adverse effects. The purpose of this study was to report and analyze symptoms after I-131 treatment within the hospitalization and present relevant medical intervention. METHODS: I-131 doses ranging from 3.7 to 9.25 GBq (100-250 mCi) were administrated for thyroid remnant ablation or treating DTC metastases. 117 patients with DTC for I-131 therapy were monitored through the video and intercommunicating with standardized questionnaire at different time points after I-131 oral administration. Adverse effects were recorded and relevant clinical factors were analyzed. RESULTS: Among all the 117 patients, 55 cases complained of neck's pain or swelling and 79 cases presented with gastrointestinal symptoms. Pain or swelling of salivary gland occurred in 15 patients, headache and vertigo in 10, insomnia in 9, vocal cord paralysis in 6, fatigue or general malaise in 6, and foreign body sensation in 5. Body numbness and urinary symptoms were observed in only 1 case, respectively. Those side effects were related with sex, pre-I-131 treatment TSH levels, frequency of I-131 therapy, and lymph node metastases. CONCLUSIONS: Short-term side effects after I-131 therapy for DTC patients varied individually; severe symptoms were not uncommon but generally did not need emergent medical intervention.

Clinical Evaluation of the Immune Colloidal Gold Method for Rapid Qualitative and Quantitative Measurement of Thyroid-Stimulating Hormone as an Assay for Hypothyroidism.

INTRODUCTION: The immune colloidal gold (ICG) method of measuring thyroid-stimulating hormone (TSH) is a rapid and easy-to-perform test, allowing off-site measurements. This study compared the clinical utility of the first ICG-based qualitative and quantitative TSH test methods in China with the third-generation serum TSH assay used worldwide. METHODS: Fingertip and venous blood was collected within 30 min from 283 patients initially suspected of hypothyroidism. TSH was measured in fingertip blood using ICG-based qualitative quantitative tests. Serum TSH in venous blood was tested using the third-generation serum TSH assay. Correlations between systems were tested by kappa or Spearman correlation coefficients. RESULTS: Compared with the third-generation serum TSH assay, the ICG-qualitative TSH test kit had a kappa coefficient of 0.86, a sensitivity of 85.00%, and a specificity of 99.38% in screening for hypothyroidism. The percentages of false negatives and false positives among all subjects were 6.38% and 0.35% respectively; the total consistency rate of the two methods was 93.26%. When compared with the third-generation serum TSH assay, the ICG-quantitative TSH analysis system had a Spearman correlation coefficient of 0.91, a sensitivity of 88.43%, and a specificity of 98.77%. The percentages of false negatives and false positives among all subjects were 4.95% and 0.71%, respectively; the total consistency rate of the two methods was 94.35%. CONCLUSION: Both ICG-based assays are easier and faster to perform than the third-generation, laboratory-based serum TSH assay method. The ICG-based methods showed acceptable performance in the simplified screening for hypothyroidism. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT01921452. FUNDING: Merck Serono Co., Ltd.

FAM172A protein promotes the proliferation of human papillary thyroid carcinoma cells via the p38 mitogen-activated protein kinase pathway.

Family with sequence similarity 172, member A (FAM172A), was cloned from human aortic tissues and confirmed in our previous study in 2009, however, its functions remain to be fully elucidated. In our previous studies, the protein expression of FAM172A in human aortic smooth muscle cells was found to be upregulated by high glucose in a concentration­ and time­dependent manner. Several reports have shown that insulin resistance is associated with papillary thyroid carcinoma (PTC). Thus, in the present study, the protein expression levels of FAM172A in human papillary thyroid carcinoma were investigated, and the effect of the FAM172A protein on the proliferation of IHH­4 human papillary thyroid carcinoma cells, and its potential molecular underlying mechanisms were examined. Immunohistochemistry and western blotting demonstrated that the protein expression of FAM172A in papillary thyroid carcinoma tissues was not only significantly higher than that in noncancerous tissues adjacent to the carcinoma tissues, but it was also markedly higher than that in normal thyroid and thyroid adenoma tissues. Overexpression of the FAM172A protein activated the p38 MAPK pathway, but not the PI3K and AMPK pathways, in the IHH­4 cells. In addition, overexpression of the FAM172A protein accelerated IHH­4 cell proliferation, compared with the control group, and the pro­proliferative effect of FAM172A protein on IHH4 cells was markedly attenuated by SB202190, an inhibitor of p38 MAPK. Taken together, these results suggest that the FAM172A protein is expressed at high levels in human PTC, which may promote cell proliferation via activation of the p38 MAPK signaling pathway, and be involved in the pathogenesis of PTC.

FDG PET/CT showing erythema nodosum associated with tuberculous lymphadenitis.

Erythema nodosum (EN) is histopathologically an acute septal panniculitis of subcutaneous adipose lobule. It can be either idiopathic or secondary to various underlying conditions. A female patient with EN underwent FDG PET/CT to search underlying cause. The images showed enlarged lymph nodes in the mediastinum with moderately elevated FDG uptake and multifocal increased FDG uptake over her lower extremities. The patient's condition was subsequently diagnosed with EN associated with mediastinal tuberculous lymphadenitis based on skin biopsy, tuberculin skin test, and treatment response.

FDG-anorectic parathyroid carcinoma with FDG-avid bone metastasis on PET/CT images.

A 53-year-old man complained of aggravated left hip pain of more than 2 months. Whole-body (18)F-FDG PET/CT revealed only 1 hypermetabolic lesion in the left ilium. Histopathologic examination of the lesion suggested metastatic disease. Blood tests documented mildly elevated blood calcium and parathyroid hormone. Subsequent neck ultrasonography, contrast-enhanced CT, and dual-phase scintigraphy with (99m)Tc-MIBI showed a right parathyroid tumor, which was confirmed to be a parathyroid carcinoma postoperatively. We report a case of parathyroid carcinoma rarely encountered with a FDG-negative primary but a FDG-positive metastasis on PET/CT images.