Acquired C1-inhibitor deficiency due to splenic marginal zone lymhoma: Case Report.

We present the case of a 67-year-old woman who suffered recurrent episodes of angioedema of the face and larynx. After thorough biochemical investigations, an acquired deficiency of C1-INH was suspected. To evaluate a potential underlying malignancy, a whole-body FDG-PET/CT was performed and showed solely a marked splenomegaly pointing towards a splenic marginal zone lymphoma, which was confirmed by pathological examination.With this case, we discuss the pathophysiology, diagnosis and management of recurrent acquired angioedema attacks as the first presentation of an underlying lymphoproliferative disease.

Ovarian cancer unmasked by technetium-99m bone scintigraphy and single-photon emission computed tomography-computed tomography.

We report a case of a 30-year-old female patient with a painless palpable nodule in the chest wall, evaluated for osseous involvement by technetium-99m (Tc-99m) bone scintigraphy. A whole-body scan revealed numerous sites of increased tracer accumulation throughout the thorax, abdomen, and pelvis. Subsequent single-photon emission computed tomography-computed tomography (SPECT-CT) of the abdomen and pelvis showed no abnormal uptake in the bone; however, significant nonosseous tracer accumulation in calcified soft tissue metastases was noted. Pathology confirmed a high-grade ovarian papillary serous adenocarcinoma. Extraosseous uptake of bone-seeking agents in the body is often incidental findings and can be explained by various benign and malignant conditions with soft tissue calcification. In our case report, this unusual finding on bone scintigraphy was highly suggestive for malignancy, initially not considered during the clinical evaluation of the patient. It also illustrates the usefulness of additional hybrid SPECT-CT to precisely localize extraosseous uptake of Tc-99m methylene diphoshonate.

Bloodpool SPECT as part of bone SPECT/CT in painful total knee arthroplasty (TKA): validation and potential biomarker of prosthesis biomechanics.

PURPOSE: To compare bloodpool SPECT with planar imaging in bone SPECT/CT of painful total knee arthroplasty (TKA) with respect to inter-rater agreement, confidence, prosthesis outcome, and biomechanical functioning. METHODS: Retrospective study of bloodpool SPECT and planar control images. Four raters used the validated Bruderholz scheme and a 5-point scale to grade uptake. Inter-rater agreement and overall confidence scores were calculated. Variable cluster analysis was performed to identify patterns of uptake, and associations between patterns and prosthesis outcome and biomechanical functioning were examined. RESULTS: In all, 55 knees in 43 patients were analyzed (median follow-up 17 months; revision rate 21.8%). SPECT significantly improved inter-rater agreement in 24% of regions (all P < 0.05) and overall confidence by 20% (P < 0.001). Regional uptake cluster analysis showed improved antero-posterior separation with SPECT, and distinct patterns associated with prosthesis survival in lateral femoral (P = 0.041) and medial tibial (P < 0.001) regions. The prognostic value of SPECT outperformed planar imaging for tibial (P < 0.001), patellar (P = 0.009), and synovial (P = 0.040) assessment. Internal femoral malrotation resulted in increased uptake in posteromedial (P = 0.042) and anterolateral (P = 0.016) femoral, and lateral patellar (P = 0.011) regions. Internal tibial malrotation increased uptake in posterolateral (P = 0.026) and posteromedial tibial (P = 0.005), and medial patellar regions (P = 0.004). Bloodpool SPECT improved the prognostic value of late-phase SPECT/CT for the assessment of the medial tibial region. CONCLUSIONS: Bloodpool SPECT outperforms planar assessment of painful TKAs and the identification of distinct uptake patterns make it a potentially clinically relevant biomarker of prosthesis survival and biomechanical functioning.

Value of 18fluorodeoxyglucose-positron-emission tomography in amyotrophic lateral sclerosis: a prospective study.

IMPORTANCE: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder primarily affecting the motor system, with extramotor involvement to a variable extent. Biomarkers for early differential diagnosis and prognosis are needed. An autosomal dominant hexanucleotide (GGGGCC) expansion in the noncoding region of the chromosome 9 open reading frame 72 (C9orf72) gene is the most frequent genetic cause of ALS, but its metabolic pattern has not been studied systematically. OBJECTIVES: To evaluate the use of 18fluorodeoxyglucose-positron-emission tomography as a marker of ALS pathology and investigate whether a specific metabolic signature is present in patients with C9orf72 mutations. DESIGN, SETTING, AND PARTICIPANTS: In total, 81 patients with a suspected diagnosis of ALS at University Hospital Leuven were prospectively investigated. All underwent detailed neurological examination and electrodiagnostic and genetic testing for the major known genetic causes of ALS (C9orf72, SOD1, TARDBP, and FUS). A diagnosis of ALS was made in 70 of 81 patients. Of these, 11 were C9orf72 positive and 59 were C9orf72 negative. In 7 patients, the diagnosis of primary lateral sclerosis was made; 4 patients had progressive muscular atrophy. A screened healthy control population was used for comparison. MAIN OUTCOMES AND MEASURES: Positron-emission tomographic data were spatially normalized and analyzed using a predefined volume of interest and a voxel-based analysis (SPM8). Discriminant analysis was done both volume of interest based and voxel based using a support vector machine approach. RESULTS: Compared with control participants, 18fluorodeoxyglucose-positron-emission tomography showed perirolandic and variable prefrontal hypometabolism in most patients. Patients with primary lateral sclerosis showed a similar pattern. Patients with C9orf72-positive ALS had discrete relative hypometabolism in the thalamus and posterior cingulate compared with those with C9orf72-negative ALS. A posteriori-corrected discriminant analysis was able to correctly classify 95% of ALS cases and 71% of primary lateral sclerosis cases. Prefrontal hypometabolism was associated with reduced clinical functioning (ALS Functional Rating Scale). Extensive hypometabolism in the prefrontal or anterior temporal areas was present in 10% of patients and associated with significantly shorter survival as an independent factor (n = 63, P < .001). Patients who were C9orf72 positive did not differ in survival compared with those who were C9orf72 negative. CONCLUSIONS AND RELEVANCE: 18Fluorodeoxyglucose-positron-emission tomography is a useful early diagnostic and prognostic marker for ALS. Amyotrophic lateral sclerosis that is positive for C9orf72 is characterized by only mild cerebral metabolic differences that show no prognostic difference.