The Importance of Radiologic Imaging Modalities in Autosomal Dominant Polycystic Kidney Disease.

Autosomal dominant polycystic kidney disease (ADPKD) is a common disorder that occurs in approximately one in 1000 live births. Patients may be asymptomatic or present with symptoms such as hypertension, hematuria, proteinuria, or renal function impairment. It can present with extra renal complications like cerebral aneurysms, hepatic and pancreatic cysts, infected cysts, cardiac valve disease, colonic diverticula, abdominal wall and inguinal hernia, and seminal vesicle cyst. Imaging studies such as ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) provide vital information regarding the diagnosis of the disease, monitoring of the progression of the disease, and detection of complications from the disease. We present the case of a 40-year-old male who developed extra-renal complications, and how different imaging modalities facilitated and enabled us to optimize the care of this patient in a timely manner.

Laboratory and imaging findings of necrotizing otitis externa are associated with pathogen type and disease outcome: A retrospective analysis.

OBJECTIVE: To examine associations of laboratory and imaging data with diagnostic parameters of necrotizing otitis externa (NOE) and its severity, and to compare between bacterial and fungal infections. METHODS: Records of patients diagnosed with NOE during 2010-2018 at the Department of Otolaryngology, Head and Neck Surgery were reviewed retrospectively for demographics; disease characteristics; and laboratory, scintigraphy, and imaging results. RESULTS: Of 48 patients with NOE, the mean age is 73±11.6 years; 32 (67%) were males; 83% had diabetes mellitus. Common pathogens were pseudomonas (49%) and fungi (33%). Sensitivities of the technetium-scan (SPECT ratio ≥1.5), temporal bone computed tomography (CT), and gallium-scan (SPECT ratio ≥1.3) were: 78.7%, 48.8%, and 31.4%, respectively. Gallium-scan results correlated positively with CT bone involvement (p=0.002) and hospital length of stay (p=0.0014). C-reactive protein (CRP) level correlated with hospital length of stay (p=0.028) and positive technetium-scan results (p=0.012). Fungal infection had a higher technetium SPECT ratio (2.16 vs. 1.77, p=0.04), gallium SPECT ratio (1.4 vs. 1.2, p=0.02), longer duration of systemic treatment (87.4 vs. 37.9 days, p=0.014), and longer hospital length of stay (31.6 vs. 15.2 days, p=0.004) compared to non-fungal infection. Eight (17%) patients had responded poorly to treatment. Fungal pathogens, facial nerve paresis, extra-auricular, and bilateral disease were more prevalent among the non-responders. CONCLUSION: The technetium scan has higher sensitivity than temporal bone CT for diagnosing NOE. The gallium scan and CRP correlated well with hospital length of stay. A high rate of fungal infection was found, with significantly higher technetium and gallium SPECT ratios and worse outcome compared to bacterial infection. Fungal NOE remains therapeutically challenging.

COVID-19 mRNA Vaccine-Associated Uveitis Leading to Diagnosis of Sarcoidosis: Case Report and Review of Literature.

A 34-year-old Japanese person with male gender identity who had been taking intramuscular injection of methyltestosterone depot for 11 years after bilateral mastectomy noticed blurred vision 5 days after the second vaccination for COVID-19 (Tozinameran; Pfizer-BioNTech) in the interval of 3 weeks following the first vaccination. The patient was diagnosed as granulomatous iritis with mutton-fat keratic precipitates and small iris nodules at the pupillary margin in the right eye and began to have 0.1% betamethasone eye drops with good response. The patient, however, continued to have fever and malaise and showed a high level of serum soluble interleukin-2 receptor (sIL-2R) even 4 weeks after the second vaccination. Computed tomographic scan disclosed mediastinal and bilateral hilar small lymphadenopathy together with limited granular lesion in the right lung. Gallium-67 scintigraphy demonstrated high uptake not only in mediastinal and hilar lymph nodes but also in bilateral parotid glands. Right parotid gland biopsy revealed noncaseating granulomas and proved pathological diagnosis of sarcoidosis. The systemic symptoms were relieved by oral prednisolone 20 mg daily. Even though the causal relationship remains undetermined, this case is unique at the point that vaccine-associated uveitis led to the detection of pulmonary lesions and lymphadenopathy, resulting in clinical and pathological diagnosis of sarcoidosis. In literature review, 3 patients showed sarcoidosis-like diseases after COVID-19 vaccination: 2 patients were diagnosed clinically as Lofgren syndrome with acute onset of erythema nodosum and ankle swelling, with or without mediastinal and hilar lymphadenopathy, whereas 1 patient with mediastinal lymphadenopathy but no uveitis was diagnosed pathologically by biopsy as sarcoidosis.

Change of Renal Gallium Uptake Correlated with Change of Inflammation Activity in Renal Pathology in Lupus Nephritis Patients.

BACKGROUND: Lupus nephritis (LN) often lead to end-stage renal disease in systemic lupus erythematosus patients. This study aimed to investigate the clinical application of renal gallium-67 scans for determining renal histological parameters in LN patients. METHODS: Between 2006 and 2018, 237 biopsy-proven and 35 repeat biopsies LN patients who underwent renal gallium scans before or after biopsy were included for analysis. The classification and scoring of LN were assessed according to the International Society of Nephrology/Renal Pathology Society. A delayed 48-h gallium scan was performed and interpreted by semiquantitative methods using left kidney/spine (K/S) ratio. The renal histological results were compared with gallium uptake. RESULTS: Out of 237 participants, 180 (76%) had proliferative LN. Baseline gallium left K/S ratio was significantly higher in class IV LN as compared to class III (median (interquartile range, IQR): 1.16 (1.0-1.3), 0.95 (0.9-1.1), respectively, p < 0.001). Furthermore, changes in gallium uptake between two biopsies were positively correlated with changes activity index (r = 0.357, p = 0.035), endocapillary hypercellularity (r = 0.385, p = 0.032), and neutrophils infiltration (r = 0.390, p = 0.030) in renal pathology. CONCLUSIONS: Renal gallium uptake is associated with active inflammation in LN. Changes in renal gallium uptake positively correlated with changes in activity index in renal pathology.

Adrenocortical carcinoma masquerading as pheochromocytoma: a histopathologic dilemma.

SUMMARY: Adrenocortical carcinoma (ACC) is an aggressive cancer that originates in the cortex of the adrenal gland and generally has a poor prognosis. ACC is rare but can be more commonly seen in those with cancer predisposition syndromes (e.g. Li-Fraumeni and Lynch Syndrome). The diagnosis of ACC is sometimes uncertain and it requires the use of precise molecular pathology; the differential diagnosis includes pheochromocytoma, adrenal adenoma, renal carcinoma, or hepatocellular carcinoma. We describe a case of a 57-year-old woman with Lynch Syndrome and metastatic ACC who was initially diagnosed as having pheochromocytoma. The tumor was first identified at 51 years of age by ultrasound followed by a CT scan. She underwent a left adrenalectomy, and the histopathology identified pheochromocytoma. Two years later, she had tumor recurrence with imaging studies showing multiple lung nodules. Following a wedge resection by video-assisted thoracoscopic surgery (VATS), histopathology was read as metastatic pheochromocytoma at one institution and metastatic ACC at another institution. She later presented to the National Institutes of Health (NIH) where the diagnosis of ACC was confirmed. Following her ACC diagnosis, she was treated with mitotane and pembrolizumab which were stopped due to side effects and progression of disease. She is currently receiving etoposide, doxorubicin, and cisplatin (EDP). This case highlights the importance of using a multi-disciplinary approach in patient care. Thorough evaluation of the tumor's pathology and analysis of the patient's genetic profile are necessary to obtain the correct diagnosis for the patient and can significantly influence the course of treatment. LEARNING POINTS: Making the diagnosis of ACC can be difficult as the differential diagnosis includes pheochromocytoma, adrenal adenoma, renal carcinoma, or hepatocellular carcinoma. Patients with Lynch Syndrome should undergo surveillance for ACC as there is evidence of an association between Lynch Syndrome and ACC. Conducting a complete tumor immunoprofile and obtaining a second opinion is very important in cases of suspected ACC in order to confirm the proper diagnosis. A multi-disciplinary approach including genetic testing and a thorough evaluation of the tumor's pathology is imperative to ensuring that the patient receives an accurate diagnosis and the appropriate treatment.

Phosphaturic mesenchymal tumors among elderly patients: a case report and review of literature.

Phosphaturic mesenchymal tumor (PMT) represents a rare cause of osteomalacia. The clinical signs and symptoms are vague and these lead to diagnosis delay. In the presence of hypophosphatemia and relatively high urine phosphate excretion, this entity should be taken into consideration in the deferential diagnosis of osteomalacia. In the present article, we report 81-year-old man presented to our clinic for evaluation due to osteopenia. His laboratory results disclosed hypophosphatemia, relatively increased urine phosphate excretion and increased level of intact fibroblast growth factor 23 (FGF23). A 68Gallium DOTATATE PET/CT revealed pathological uptake in the upper aspect of the left shoulder adjacent to the coracoid process. For suspected PMT a wide resection of the tumor was performed and pathological findings were consistent for PMT. Laboratory tests were normalized postoperatively. Reviewing the literature, we had identified 33 reported cases of PMTs among elderly patients age ≥70 years. Unlike previously reported data, where tumors predominantly localized in the lower extremities and pelvis, our search disclosed a high rate of tumor localization (10 cases - 33.3%) in the head with equal number of tumors (14 cases - 42.4%) localized in the head and upper extremity as well as in pelvis and lower extremity. The present case describes unique tumor localization in an elderly patient and our literature search demonstrated for the first time a high rate of tumor localization in the head among this group of patients. Learning points: PMTs represent a rare entity that should be considered in the differential diagnosis of elderly patients presented with persistent hypophosphatemia. Unlike previously reported data, head and neck tumor localization is frequent among elderly patients. 68Gallium-conjugated somatostatin peptide analogs, such as 68Ga-DOTATATE PET/CT demonstrated the greatest sensitivity and specificity for tumor localization in patients with phosphaturic mesenchymal tumors (PMTs). Wide tumor resection using intraoperative ultrasound is of major importance in order to ensure long-term cure.

Paraganglioma presenting as stress cardiomyopathy: case report and literature review.

Pheochromocytoma/paraganglioma (PPGL) are neuroendocrine tumors that can secrete catecholamines. The authors describe a challenging case who presented as stress cardiomyopathy and myocardial infarction (MI). A 76-year-old man, with a medical history of Parkinson's disease, type 2 diabetes mellitus, hypertension, dyslipidaemia and a previous inferior MI in 2001, presented to the emergency department due to chest pain, headaches and vomiting. He also reported worsening blood glucose levels and increasing constipation over the preceding weeks. BP was 185/89 mmHg (no other relevant findings). EKG had ST segment depression in leads V2-V6, T troponin was 600 ng/L (<14) and the echocardiogram showed left ventricular hypokinesia with mildly compromised systolic function. Nevertheless, he rapidly progressed to severe biventricular dysfunction. Coronary angiogram showed a 90% anterior descendent coronary artery occlusion (already present in 2001), which was treated with angioplasty/stenting. In the following days, a very labile BP profile and unexplained sinus tachycardia episodes were observed. Because of sustained severe constipation, the patient underwent an abdominal CT that revealed a retroperitoneal, heterogeneous, hypervascular mass on the right (62 × 35 mm), most likely a paraganglioma. Urinary metanephrines were increased several fold. 68Ga-DOTANOC PET-CT scan showed increased uptake in the abdominal mass (no evidence of disease elsewhere). He was started on a calcium-channel blocker and alpha blockade and underwent surgery with no major complications. Eight months after surgery, the patient has no evidence of disease. Genetic testing was negative for known germline mutations. This was a challenging diagnosis, but it was essential for adequate cardiovascular stabilization and to reduce further morbidity. Learning points: PPGL frequently produces catecholamines and can manifest with several cardiovascular syndromes, including stress cardiomyopathy and myocardial infarction. Even in the presence of coronary artery disease (CAD), PPGL should be suspected if signs or symptoms attributed to catecholamine excess are present (in this case, high blood pressure, worsening hyperglycaemia and constipation). Establishing the correct diagnosis is important for adequate treatment choice. Inodilators and mechanical support might be preferable options (if available) for cardiovascular stabilization prior to alpha blockade and surgery. Laboratory interference should be suspected irrespective of metanephrine levels, especially in the context of treated Parkinson's disease.

Lesson of the month 1: Subacute thyroiditis: a rare cause of fever of unknown origin.

Fever of unknown origin (FUO) is sometimes a diagnostic dilemma for clinicians. Endocrine causes reported in the literature include subacute thyroiditis, thyrotoxicosis, adrenal insufficiency and pheochromocytoma. Among these, subacute thyroiditis is often overlooked as it can occasionally lack typical symptoms. This case illustrates the fact that subacute thyroiditis should be considered as a possible cause of fever even if signs and symptoms of hyperthyroidism and thyroid tenderness are absent.

Bone and Gallium Single-Photon Emission Computed Tomography-Computed Tomography is Equivalent to Magnetic Resonance Imaging in the Diagnosis of Infectious Spondylodiscitis: A Retrospective Study.

OBJECTIVES: Spondylodiscitis has historically been a difficult clinical diagnosis. Two imaging techniques that address this problem are magnetic resonance imaging (MRI) and combined bone (99mTc-methylene diphosphonate) and gallium-67 single-photon emission computed tomography-computed tomography (SPECT-CT). Their accuracies have not been adequately compared. The purpose of this study is to compare the sensitivities and specificities of bone and gallium SPECT-CT and MRI in infectious spondylodiscitis. METHODS: This retrospective study assessed all patients who underwent a bone or gallium SPECT-CT of the spine to assess for infectious spondylodiscitis from January 1, 2010, to May 2, 2012, at a single tertiary care centre. Thirty-four patients (23 men; average 62 ± 14 years of age) were included. The results of the bone or gallium SPECT-CT were compared against MRI for all patients in the cohort who underwent an MRI within 12 weeks of the SPECT-CT. A diagnosis of spondylodiscitis in the discharge summary was considered the reference standard, and was based on a combination of clinical scenario, response to therapy, imaging, or microbiology. RESULTS: Spondylodiscitis was diagnosed in 18 patients and excluded in 16. Bone or gallium SPECT-CT and MRI had similar (P > .05; κ = 0.74) sensitivities (0.94 vs 0.94), specificities (1.00 vs 1.00), positive predictive values (1.00 vs 1.00), negative predictive values (0.94 vs 0.80), and accuracies (0.97 vs 0.95) when compared to the reference standard. CONCLUSION: Although MRI remains the initial modality of choice in diagnosing spondylodiscitis, bone and gallium SPECT-CT appears diagnostically equivalent and should be considered a viable supplementary or alternative imaging modality particularly if there is contraindication or inaccessibility to MRI.

Clinical pretreatment risk factors and prediction of outcome using gallium 67 scintigraphy in patients with Hodgkin's lymphoma.

This study was conducted to investigate the prognostic effect and implications of gallium 67 scintigraphy (gallium scan) at mid-treatment and at the end of first-line treatment in patients with early- and advanced-stage Hodgkin's lymphoma (HL). A total of 216 HL patients were included in the study. Gallium scan was performed at mid-treatment and at the end of first-line treatment. The overall survival (OS) and event-free survival (EFS) were calculated using the Kaplan-Meier method. The log-rank test was used to identify univariate predictors of EFS and OS. For early-stage disease, bulky mediastinal involvement (yes vs. no, 98 vs. 79%, respectively; P=0.01), erythrocyte sedimentation rate (good vs. adverse, 98 vs. 88%, respectively; P=0.03), presence of B symptoms (no vs. yes, 94 vs. 78%, respectively; P=0.006), post-chemotherapy disease status [complete response (CR) vs. unconfirmed CR (uCR) vs. partial response (PR) vs. progressive disease (PGR), 95 vs. 90 vs. 87 vs. 0%, respectively; P<0.01] and gallium scan at mid-treatment and at the end of treatment (negative vs. positive, 88 vs. 20%, P<0.001; and 85 vs. 10%, P<0.001, respectively) significantly affected the EFS. In addition, age (<50 vs. ≥50 years, 96 vs. 78%, respectively; P=0.01), presence of B symptoms (no vs. yes, 97 vs. 87%, respectively; P=0.03), post-chemotherapy disease status (CR vs. uCR vs. PR vs. PGR, 95 vs. 90 vs. 90 vs. 0%, respectively; P<0.01) and gallium scan results at mid-treatment and at the end of treatment (negative vs. positive, 87 vs. 60%, P<0.001; and 95 vs. 0%, P<0.001, respectively) significantly affected the OS. For advanced-stage disease, Hassenclever index (1-3 vs. 4-6, 80 vs. 57%, respectively; P=0.05) and gallium scan results at mid-treatment and at the end of treatment (negative vs. positive, 84 vs. 18%, P<0.001; and 84 vs. 0%, P<0.001, respectively) significantly affected the EFS, whereas age at diagnosis (<50 vs. ≥50 years, 92 vs. 78%, respectively; P=0.04), Hassenclever index (1-3 vs. 4-6, 86 vs. 61%, respectively; P=0.04) and gallium scan results at mid-treatment and at the end of treatment (negative vs. positive, 98 vs. 40%, P<0.001; and 97 vs. 23%, P<0.001, respectively) significantly affected the OS. On the multivariate analysis, gallium scan at the end of first-line treatment retained statistical significance in terms of EFS and OS. In conclusion, post-chemotherapy gallium scan is an important prognostic factor in patients with early- or advanced-stage HL and a predictor of adverse outcome.

Neurosarcoidosis as an MS Mimic: The trials and tribulations of making a diagnosis.

The clinical presentation of neurosarcoidosis is varied as multiple levels of the neuraxis may be affected. When central nervous system involvement occurs, making an accurate diagnosis of the condition can be challenging, especially given the current definition for definite neurosarcoidosis requires histologic confirmation of the affected tissue (brain biopsy). This article will review our current knowledge and manifestations of neurosarcoidosis, discuss the current diagnostic approach as well as the challenges associated with a condition requiring histologic confirmation, discuss the current treatment approach, and highlight the challenges of this diagnosis with a few real-life clinical cases. We also highlight the selected differential diagnosis of neurosarcoidosis as well as multiple sclerosis which could mimic each other.

Escherichia coli - Marauding masquerading microbe.

BACKGROUND: Escherichia coli is a rare cause of monoarticular septic arthritis, but is an even rarer cause of polyarticular septic arthritis. CASE DESCRIPTION: We report an unusual case of polyarticular septic arthritis with an atypical presentation caused by E. coli, the source of which was a left pyelonephritis. Our patient developed E coli sepsis resulting in polyarticular septic arthritis (PASA) in the absence of typical risk factors except for pre-existing osteoarthritis. The joints involved were the hip, ankle, sternoclavicular and L5/S1 joints. Of interest, ankle pain was not reported or evident until correlated with nuclear medicine scans. Furthermore, sternoclavicular joint involvement presented as left shoulder pain, resulting in an initial misdiagnosis of left shoulder septic arthritis. The patient was treated with surgical washout and antibiotic therapy. He was subsequently discharged from rehabilitation having returned to his baseline level of mobility. Future consideration will be given to total hip arthroplasty. LITERATURE REVIEW: There are no reported cases of E. coli PASA involving more than three joints in the absence of any recognized risk factors for septic arthritis. PURPOSE AND CLINICAL RELEVANCE: Asymptomatic involvement of joints can occur in polyarticular septic arthritis and should be considered in all cases of monoarticular septic arthritis (MASA). We believe that clinical suspicion is the key to early and comprehensive diagnosis of polyarticular septic arthritis particularly when presenting in an atypical fashion with an atypical pathogen. Strong consideration should be given to performing nuclear imaging in cases of monoarticular septic arthritis where polyarticular involvement cannot be definitively ruled out.

An unusual case of gallium scan mimicking a bone scan.

Gallium-67 localization is based on the fact that it binds to plasma proteins like transferrin and lactoferrin, which have iron-binding sites. Abnormal biodistribution of gallium-67 citrate can occur in iron-overload states. We report one such case of gallium scan mimicking a bone scan due to skeletal uptake of gallium.

Gallium scan in diagnosing ocular sarcoidosis.

A 40-year-old man presented with floaters and painless progressive blurring of vision in the right eye for one month duration. Visual acuity in the right eye was 6/24. There was mild anterior chamber reaction and vitritis. The optic disc was swollen and elevated with presence of granulomatous lesion in the optic disc head. Blood investigations were unremarkable. Serum angiotensin converting enzyme (ACE) was normal and conjunctival biopsy showed presence of inflammatory cells. B-Scan ultrasound revealed an echo-dense lesion in the optic nerve head. There was increased uptake of the right lacrimal gland and presence of 'Panda sign' with Gallium scan. A diagnosis of right ocular sarcoidosis was made base on the clinical features and Gallium scan.