Rosai-Dorfman disease in a symptomatic elderly man.

An 81-year-old man presented with anemia, fatigue, weight loss, and recurrent urinary tract infections and was found to have diffuse large adenopathy and infiltrating renal masses. Surgical excision of a lymph node and histologic evaluation led to the diagnosis of Rosai-Dorfman disease, a rare histioproliferative condition that classically presents with enlarged cervical lymph nodes bilaterally. It also can involve additional nodal chains and/or have extranodal manifestations. The condition can self-resolve or have periods of remission and reactivation.

Use of 68Ga DOTATATE, a new molecular imaging agent, for neuroendocrine tumors.

Neuroendocrine tumors (NET), such as insulinomas and carcinoid tumors, can be challenging to diagnose since patients often present with vague symptoms. Adding to the challenge, these tumors are often occult on typical cross-sectional imaging modalities. Because of these challenges, there has been an increase in the utilization of radiopharmaceuticals that take advantage of specific receptors expressed by NET. Among the multiple radiopharmaceuticals that can be used, 68Ga DOTATATE is emerging as the most sensitive and specific imaging agent. We present a case where 68Ga DOTATATE was used to diagnose a well-differentiated neuroendocrine tumor.

Optimal interpretative strategy for preoperative parathyroid scintigraphy.

PURPOSE: Our objective was to retrospectively compare various scintigraphic methods to determine their relative accuracies and interobserver variabilities in preoperative localization of single-gland disease in patients with primary hyperparathyroidism. PATIENTS AND METHODS: We studied 292 patients who underwent preoperative parathyroid scintigraphy and surgical resection between June 2002 and September 2008. Imaging included early and delayed pinhole Tc-MIBI imaging (including anterior oblique images), similar I imaging, and MIBI SPECT. Seven different imaging combinations were assessed as follows: early MIBI only, delayed MIBI only, comparison of dual-phase early and delayed MIBI, visual subtraction of early MIBI and I images, all planar images, SPECT only, and all planar and SPECT images (ALL). Each data set was reviewed by 2 of 4 experienced nuclear physicians without knowledge of clinical information or final diagnosis. Imaging results were compared with surgical outcomes. RESULTS: The accuracy of ALL imaging for delineating abnormal/normal parathyroid glands by quadrant was 96%, 93%, 95%, and 95% for the 4 readers. The accuracies of visual subtraction of early MIBI and I images and all planar images were not significantly different from ALL for all 4 readers. All planar and SPECT images were significantly more accurate than early MIBI only, delayed MIBI only, or SPECT only for all 4 readers and better than comparison of dual-phase early and delayed MIBI for 3 of 4 readers. CONCLUSIONS: A rigorous combination of multiple imaging approaches yielded high accuracies across multiple readers for localization of a single offending parathyroid gland, but a more limited technique using MIBI/I subtraction imaging with anterior and anterior oblique pinhole images provided similarly high accuracy and limited interobserver variation of accuracy.

Utility of pattern recognition in the detection of unsuspected additional primary malignancies on positron emission tomography-computed tomography.

Positron emission tomography-computed tomography (PET-CT) has been shown to detect unexpected synchronous malignancies in up to 4.8% of patients and has been shown to be more sensitive than conventional staging alone. Detection of an unsuspected synchronous malignancy on PET-CT will often affect both patient treatment and prognosis. This article reviews expected patterns of disease spread so that a synchronous malignancy can be more easily recognized.

Imaging HIV/AIDS. Body cavity-based lymphoma.

Non-Hodgkin's lymphoma (NHL) is an important and common AIDS-related neoplasm. AIDS-related NHL can be defined by its anatomic distribution as systemic (nodal and extranodal masses), primary central nervous system, and occasionally body cavity-based lymphomas (BCBL). Radiologic imaging plays an important role in differentiating the varied appearances of AIDS-related NHL, particularly regarding BCBL: patients' images demonstrate only fluid in the pleural, pericardial, and/or peritoneal spaces. Imaging of a case of BCBL is presented, including simultaneous pericardial, pleural, and peritoneal effusions.