Multimodality Molecular Imaging in Arthropathy Associated with Multiple Myeloma.

We report a patient with multiple myeloma (MM) and polyarthritis of large joints. During the staging of the disease, bone marrow diffusely involved by MM was clearly demonstrated by 99mTc-2-methoxy-isobutyl-isonitrile (MIBI) single-photon emission computed tomography/computed tomography (SPECT/CT) but not by 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/CT images. On the other hand, a very intense uptake of 18F-FDG was detected in periarticular tissues of multiple joints, with nonabnormal 99mTc-MIBI accumulation. Rheumatology tests were negative. A subsequent bone scintigraphy demonstrated radiolabeled bisphosphonate accumulation in periarticular tissues, suggesting amyloid arthropathy.

Head-to-head comparison between 68Ga-PSMA and 18F-FDG-PET/CT in lymphomas: a preliminary analysis.

PURPOSE: Isolated case reports mention the uptake of radiolabeled PSMA in lymphoma. However, it is not clear if the intensity of 68Ga-PSMA expression varies among different histological subtypes or if it correlates with 18F-FDG uptake. This study compared both tracers in patients with diverse lymphoma subtypes. METHODS: Ten patients with biopsy-proven-lymphoma underwent 18F-FDG and 68Ga-PSMA-PET/CT (maximum time interval: 6 days). Lymphoma subtypes included Hodgkin's lymphoma (HL, three patients) and aggressive and indolent non-Hodgkin's lymphoma (NHL, seven patients). The intensity of PSMA uptake was classified visually as low, intermediate, or high, using blood pool, liver and parotid gland uptake as references. Maximum standardized-uptake value (SUVmax) of each affected site was measured in both sets of images. RESULTS: FDG detected 59/59 involved sites in 10 patients and PSMA 47/59 sites in nine patients. PSMA uptake was generally low, regardless of the intensity of FDG uptake, but it was classified as intermediate in two patients. The median SUVmax varied from 2.0 (2.0-8.2) to 30.9 for FDG and from 1.7 (1.7-1.7) to 4.4 for PSMA, P < 0.0001. The primary lesion of one patient had a marked intralesional mismatch uptake pattern of the tracers, with areas of higher PSMA expression than FDG uptake, and vice-versa. A brain lesion was more easily identified with PSMA than with FDG images. CONCLUSION: HL and several NHL subtypes may present PSMA uptake. The intensity of PSMA expression is generally lower than that of FDG uptake and seems to present less variation among the different histological subtypes of lymphomas.

Dermal vasculature and melanocytic proliferation index in photodamaged skin in the assessment of lateral margins of lentigo maligna and lentigo maligna melanoma.

Lentigo maligna (LM) is the most common subtype of melanoma on the face. When it invades the dermis it is called lentigo maligna melanoma (LMM). Its histological delimitation is controversial due to subjectivity. Analysis of peritumoral vasculature and proliferation index of melanocytes may help to differentiate tumor areas from tumor-free areas, as neoplasia-induced angiogenesis in such scenarios, as well as the higher proliferation index of melanocytes in melanomas, are well established. This work compares the peritumoral vasculature and melanocyte proliferation index of LM and LMM with that of adjacent non-neoplastic skin and sun-damaged skin (control). Forty-three resection cases of LM and LMM were selected retrospectively. Immunohistochemistry was performed for anti-CD31 and anti-CD105 to assess vascularization. Melanocyte proliferation index double labeling was performed using the anti-Melan-A and anti-Ki-67. The Chalkley optical grid was used to quantify blood vessel hotspots. Doubly labeled cells with anti-Melan-A and anti-Ki-67 were counted at tumor, free margin, and control skin. Microvasculature quantification under the melanomas, for both CD31 and CD105, was greater than at the margins of the same specimens (P < 0.0001; P = 0.0001) and greater than control skin (P = 0.0016; P = 0.0027), with higher density for CD31 than CD105. The mean number of double-labeled proliferating melanocytes at the melanoma periphery was greater than at the adjacent free skin and control skin (P = 0.0011). The control skin samples showed the highest CD31-positive vasculature in the head and neck region, with a positive correlation between melanocytic proliferation index and vasculature. The presence of neovascularization (CD105) and proliferating melanocytes (Ki67+/Melan-A+) are suspicious findings for LM/LMM, helping to outline, diagnose, and evaluate tumor margins.