Occult breast primary malignancy presenting as isolated axillary lymph node metastasis — early detection of primary site by 18F-FDG PET/CT

Breast cancer patients rarely present with isolated axillary lymph node metastasis without any clinical or radiological evidence of primary tumor. Identification of the primary site of tumor helps in planning appropriate patient management which has definite impact on patient’s survival. We present here a case of 30-year-old female who presented with isolated right axillary lymph node metastasis with no evidence of primary tumor clinically. Conventional imaging modalities were negative for primary site. She underwent whole body 18F-Flurodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and it contributed significantly in early detection of occult primary tumor in right breast

Hybrid SPECT-CT with 99mTc-labeled red blood cell in a case of blue rubber bleb nevus syndrome: added value over planar scintigraphy

Blue rubber bleb nevus syndrome (BRBNS) is a rare vascular anomaly syndrome consisting of multifocal venous malformations most commonly involving the skin, soft tissues, and gastrointestinal tract. The gastrointestinal lesions of BRBNS are the most clinically relevant malformations and carry a significant potential for serious bleeding. William Bennet Bean first coined the term “BRBNS” in 1958, and only 200 cases have been described since then (1). A few reports have described the use of 99mechnetium (99mTc)-labeled red blood cell (RBC) planar scintigraphy in BRBNS patients to localize the site of bleeding (2–5). To the best of our knowledge, however, the role of single-photon emission computed tomography-computed tomography (SPECT-CT) in examining such patients has not been evaluated. Here, we report the value of 99mTc-labeled RBC hybrid SPECT-CT over planar scintigraphy alone in a patient with BRBNS

Primary penile lymphoma: the use of PET-CT for accurate staging and response monitoring

Primary penile lymphoma is an extremely rare neoplasm. We present a case of 63-year-old man with painless diffuse pe- nile swelling and retention of urine. Biopsy from the penile swelling demonstrated CD20+ diffuse large B-cell lymphoma. Staging was performed using fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) and revealed a FDG avid penile mass with enlarged and FDG avid multiple inguinal and aortocaval lymph nodes. A follow-up FDG PET-CT scan after eight cycles of combina- tion chemotherapy showed complete remission of the dis- ease. Thus, FDG PET-CT should be integrated in management protocols of rare primary penile lymphoma

Preoperative characterization of indeterminate large adrenal masses with dual tracer PET-CT using fluorine-18 fluorodeoxyglucose and gallium-68-DOTANOC: initial results

PURPOSEWe aimed to evaluate the usefulness of dual tracer positron emission tomography-computed tomography (PET-CT) with flourine-18 fluorodeoxyglucose (18F-FDG) and gallium-68 [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-NaI3-octreotide (68Ga-DOTANOC) in preoperative characterization of large indeterminate adrenal masses.MATERIALS AND METHODSTen patients (four males, six females; median age, 35 years) with indeterminate, large (≥4 cm) adrenal masses were included in this prospective study. All patients underwent both 18F-FDG PET-CT and 68Ga-DOTANOC PET-CT within one week. Images were evaluated both visually and semi-quantitatively, with standardized uptake value (SUVmax) and SUVratio (SUVmax) of tumor/SUVmax) of mediastinum). Based on differential uptake pattern on 18F-FDG and 68Ga-DOTANOC, lesions were classified as cortical (18F-FDG>68Ga-DOTANOC), medullary (68Ga-DOTANOC>18F-FDG), or indeterminate (18F-FDG=68Ga-DOTANOC). Histopathology was taken as reference standard. Receiver operating characteristic (ROC) analysis was performed to find a cut-off of SUVmax) and SUVratio to differentiate cortical and medullary lesions.RESULTSOn histopathology, eight lesions were adrenocortical carcinomas, one was benign pheochromocytoma, and one was malignant pheochromocytoma. Visually, 18F-FDG PET-CT was positive in all ten lesions, while 68Ga-DOTANOC PET-CT was positive in two, both of which were pheochromocytomas. On SUVmax) based analysis, nine lesions were cortical and one was medullary. On ROC analysis, a SUVmax) cut-off of > 2.3 was obtained for 18F-FDG PET-CT and 3.6 for 68Ga-DOTANOC PET-CT for differentiating adrenal cortical and medullary lesions. The cut-off for SUVratio was 4.5 on 18F-FDG PET-CT and 11.1 on 68Ga-DOTANOC PET-CT.CONCLUSIONThese preliminary results demonstrate that dual tracer PET-CT using 18F-FDG and 68Ga-DOTANOC could be informative in the preoperative characterization of large indeterminate adrenal masses

SPECT-CT for characterization of extraosseous uptake of 99mTc-methylene diphosphonate on bone scintigraphy

Bone scintigraphy is a sensitive and popular method for imaging a wide array of benign or malignant skeletal abnormalities. However, the uptake of tracers used for bone scintigraphy may be observed in various extraosseous sites, thereby limiting its specificity. It is difficult to correctly localize such sites of uptake on planar bone scintigraphy alone. The addition of hybrid single-photon emission computed tomography-computed tomography (SPECT-CT) under such circumstances is very useful. The present essay illustrates the commonly encountered extraosseous uptake of 99mTc-methylene diphosphonate (MDP) and the usefulness of hybrid SPECT-CT in clarifying 99mTc-MDP uptake

Re-establishment of normal radioactive iodine uptake reference range in the era of universal salt iodization in the Indian population

Background & objectives: The reference radioactive iodine uptake (RAIU) values established in the 1970s in the era of widespread iodine deficiency were relatively high. Now, after four decades of successful Universal Salt Iodization (USI) programme in India, there is a need to re-establish these reference ranges. The present study was aimed to quantify the two-hour and 24-h RAIU values in iodine sufficient euthyroid individuals and validate the results in Graves' and Hashimoto's thyroiditis patients. Methods: In this prospective study conducted from April 2012 to September 2013, euthyroid volunteers who consented for the investigations were enrolled in the study. Treatment-naive Graves' disease and Hashimoto's thyroiditis patients were recruited from the outpatient clinic. The investigations included neck ultrasonography, thyroid function tests, thyroglobulin (Tg), anti-Tg and anti-thyroid peroxidase antibody and urinary iodine concentration. Results: Three different groups comprising 110 euthyroid volunteers, 38 Graves' and 17 Hashimoto's thyroiditis patients were enrolled in the study. The mean 2-h RAIU values for the euthyroid group, Hashimoto's thyroiditis and Graves' patients were 3.83±2.77, 4.22±3.41 and 32.67±15.93 per cent, and mean 24-h RAIU values were 12.75±5.51, 11.66±9.55 and 61.85±12.9 per cent, respectively. The mean thyroid volumes were 7.63±2.72, 7.81±1.67 and 20.76±12.56 ml for the euthyroid, Hashimoto's thyroiditis and Graves' disease groups and the mean spot urinary iodine concentrations were 9.0, 7.8 and 13.9 μg/dl in the three groups, respectively. The new reference range (95% confidence interval) for two-hour was 1-7 per cent and 24-h was 7-18 per cent. Interpretation & conclusions: Compared to the previous values, there was a considerable decrease in the RAIU values in euthyroid individuals. This was further corroborated with increase in the urinary iodine concentration and decrease in thyroid volume, attributed to successful USI programme. Further studies with a large sample from different parts of India need to be done to confirm these findings

A curious case of refractory hypothyroidism due to selective malabsorption of oral thyroxine

There are very few cases in the literature in which refractory persistent hypothyroidism responded only to parenteral doses of levothyroxine and no evidence of any malabsorptive disorder could be identified. Here, we present a rare case of a 35-year-old woman with refractory hypothyroidism who responded only to intravenous doses of levothyroxine. We also discuss possible causes for the same

Incidental detection of hyperfunctioning thyroid cancer metastases in patients presenting with thyrotoxicosis

Thyrotoxicosis due to functioning metastases from thyroid cancer is rare. It also presents a therapeutic challenge, as both the metastatic cancer and thyrotoxicosis need to be treated. We present here two cases of thyrotoxicosis which on a routine 99m Tc-pertechnetate thyroid scan showed extrathyroidal foci of uptake. Two patients who initially presented with thyrotoxicosis underwent a routine thyroid scan. Abnormal uptake in the shoulder was incidentally noted, which prompted us to do a whole body pertechnetate scan in the same sitting, which revealed extensive hyperfunctioning metastases in the lungs and bones. We also discuss the ′Flip Flop′ phenomenon in thyroid cancer, which was seen in our case. This report emphasizes the importance of evaluating the abnormal foci of uptake seen on a routine thyroid scan

CMV genotyping using different samples in post renal transplant recipients with CMV disease

CMV is the most common viral infection which occurs in post renal transplant recipients (PTR). There are four different gB genotypes (gB1 to gB4) which exist in CMV. Studies have reported that mixed infection with different genotypes will cause severe clinical manifestations as well as co-infection with other herpesvirus including Epstein-Barr virus (EBV) [1]. CMV can cause compartmentalized disease involving different organs with different genotypes. There are reports in immuno compromised individuals with different genotypes [2, 3]. Institutional ethics committee approval was obtained prior to conduct of the study (IEC-NI/08/DEC/07/46). Whole blood, saliva and urine were collected from PTR. DNA were extracted (Qiagen DNA mini kit) and CMV quantitative PCR targeting ppUL83 gene was performed with CMV R-gene™ using an ABI 7900 Fast real time PCR (SDS Version: 2.4). PTR who had high viral load (>1000 copies/ml) in any three or two samples were included for CMV genotyping PCR targeting gB region (410-bp) [2]. DNA sequencing was performed in ABI 3730 GA platform by Sanger method and sequences were analyzed by reference strains. A total of 24 samples were collected from 9 PTR. Among these four PTR had high viral load in all three samples (whole blood, urine & saliva) and those with high viral load (n=5) in 2 samples (Whole blood & urine/saliva) were screened for CMV genotyping. Majority of the strains belonged to genotype B1 and only one PTR was infected with genotype B2 in three samples. In PTR with genotype B1, gastro intestinal infection (GI) was predominantly found in 78% (n=7) followed by graft dysfunction (GDF) in 56% (n=5) of the PTR. PTR who detected with genotype B2 was associated with fever, leukopenia (CMV syndrome), GDF and also found with EBV infection. Co-infection with EBV was observed in 44% (n=4); VZV and HSV type 1 was also observed. Genotypes are associated with the severity of the disease and co-infection with other herpes virus infections. In our study subjects, genotype B1 predominantly noted as reported in western countries. Study on distribution of genotypes among PTR may help to determine the specific strains for vaccine development