Incidentally Detected Celiac Disease with Splenomegaly on 18F FDG PET/CT: A Potential Lymphoma Mimic.

Celiac disease is an immune-mediated disorder triggered by hypersensitivity to gluten occurring in genetically susceptible individuals. A high-index of suspicion is needed for diagnosis as patients can be asymptomatic or present with atypical symptoms or extra-intestinal manifestations. Typical 18F-Fluorodeoxyglucose (FDG) Positron Emission Tomography (PET)/Computed Tomography (CT) gastrointestinal manifestations of celiac disease include increased multifocal or diffuse jejunal and ileal uptake; focal duodenal uptake is less common. Splenomegaly with increased splenic FDG uptake is also uncommon in celiac disease in the absence of portal hypertension; small-sized spleen and functional hyposplenism are more typical. We report a case of celiac disease diagnosed after PET/CT showed FDG uptake in the duodenum and enlarged spleen. Follow-up after gluten-free diet showed complete metabolic resolution and regression of splenomegaly. The combination of focal bowel and splenic uptake is unusual in celiac disease and may be mistaken for a lymphoproliferative disorder. Awareness of this entity may avoid misdiagnosis and guide appropriate management.

Immunohistochemistry for TFE3 lacks specificity and sensitivity in the diagnosis of TFE3-rearranged neoplasms: a comparative, 2-laboratory study.

TFE3 rearrangements are characteristic of alveolar soft part sarcomas (ASPS), Xp11.2 translocation renal cell carcinomas (Xp11-RCC), and other rare tumors. Immunohistochemistry for TFE3 protein has been considered by some to be a reliable surrogate for TFE3 molecular studies, although others disagree. We compared 2 methods for TFE3 immunohistochemistry to determine if technical differences underlie these differences. Ninety-eight archival cases of mixed type, 19 ASPS, and 8 Xp11-RCC were stained for TFE3 at Laboratory A and Laboratory B using routine protocols. Positive controls were normal human testis (Laboratory A) and Xp11-RCC (Laboratory B). Nuclear staining was scored as "negative," "1+" (<10%), "2+" (10%-50%), and "3+" (>50%). Intensity was scored as "negative," "weak," "moderate," or "strong." Only moderate-strong, 2+ or 3+ staining was considered positive. Laboratory A results were as follows: archival cases (42 of 98, 43%), ASPS (16 of 19, 84%), and Xp11-RCC (7 of 8, 88%). Laboratory B results were as follows: archival cases (5 of 98, 5%), ASPS (14 of 19, 74%), and Xp11-RCC (5 of 8, 63%). TFE3 fluorescence in situ hybridization was positive in all tested ASPS and Xp11-RCC. The overall sensitivity and specificity of TFE3 immunohistochemistry for TFE3-rearranged neoplasms were 85% (23/27) and 57% (56/98) at Laboratory A and 70% (19/27) and 95% (93/98) at Laboratory B. Technical differences, in particular, the type of control tissue, likely account for these different results. The results of our study and prior studies suggest that TFE3 immunohistochemistry should play only a minor role (if any) in the diagnosis of TFE3-rearranged tumors, with fluorescence in situ hybridization representing the preferred method.

Treatment of lumbar vertebra epithelioid hemangioma with radiation therapy: a case report.

BACKGROUND: Although epithelioid hemangiomas involving bone have been described in previous case reports and case series, the effects of radiation therapy on vertebral epithelioid hemangioma has not been fully reported. Here we provide a case report of tumor response to radiation therapy in a young adult with a large epithelioid hemangioma involving the fourth lumbar vertebrae. CASE PRESENTATION: A 27-year-old Latino man with a past medical history of type 1 diabetes and a 3-year history of low back pain presented to a hospital emergency department following acute worsening of back pain. On transfer to our tertiary medical center, he described the pain as "shock-like" which originated at the lateral aspect of his right hip and radiated down to his right knee. Paresthesia was also reported along the medial aspect of his lower right leg. Imaging included a computed tomography scan and magnetic resonance imaging which revealed fourth lumbar and right iliac lytic bone lesions. Image-guided biopsies of the lytic lesions were consistent with a diagnosis of epithelioid hemangioma and radiation therapy was recommended as the primary treatment. Our patient's low back and leg pain were initially managed with acetaminophen, oxycodone, pregabalin, and lidocaine patch 5%. He noted improvement in pain after his third fraction of radiation. Pain intensity continued to decline and oxycodone was discontinued. CONCLUSIONS: This case report demonstrates an unusual etiology of back and leg pain in a young man and elucidates the palliative effects of radiation therapy for epithelioid hemangioma involving the lumbar spine.