Brucellosis is a zoonotic infection, endemic in rural areas. It is caused by Brucella species, which are transmitted through the intake of unpasteurized dairy products and contact with infected animals. Sacroiliac joint involvement is common in brucellosis and typically presents as unilateral sacroiliitis. Contrarily, bilateral sacroiliitis is less typical and may mimic tuberculosis, pyogenic infection, or inflammatory spondyloarthropathy. We report a case of a 19-year-old man who presented with a one-month history of bilateral buttock pain radiating to the legs and a 2-week history of fever, chills, rigors, and febrile diaphoresis. He reported unpasteurized milk intake. Physical examination revealed bilateral sacroiliac joint tenderness, and Patrick's and Gaenslen's provocation tests elicited pain in both sacroiliac joints. Laboratory findings showed leukocytosis, elevated CRP, and ESR. Standard agglutination testing was positive for anti-Brucella antibodies, and MRI confirmed bilateral sacroiliitis, along with erosive changes and marrow edema. A diagnosis of brucellosis complicated by bilateral sacroiliitis was proposed. The patient was started on doxycycline, co-trimoxazole, and gentamicin. Gentamicin was used for 22 days, while doxycycline and co-trimoxazole were continued for a total planned duration of 13 weeks. During follow-up visits (day 15 and day 45), the patient demonstrated clinical improvement, evident by laboratory parameters, pain improvement, no fever, difficulty walking, and medication-related adverse effects. This case emphasizes that clinicians in endemic areas must consider brucellosis as a differential diagnosis in patients with bilateral lower back or buttock pain. MRI findings and serology testing are useful in early recognition. While blood cultures, PCR, and biopsy are necessary for definitive diagnosis.

Kaposi sarcoma (KS) is an acquired immunodeficiency syndrome (AIDS)-defining malignancy that can involve the skin, lymph nodes, and visceral organs in patients with advanced human immunodeficiency virus (HIV). We report the case of a 35-year-old man with no known prior medical history who presented to the charity care clinic complaining of recurrent thrush and two weeks of progressive right lower extremity swelling. His physical examination revealed painful, pruritic violaceous papules and plaques over the proximal right thigh that had been present for one week. He was referred to the emergency department (ED) for further workup. Venous duplex ultrasonography was negative for deep venous thrombosis (DVT). He was found to have a newly diagnosed HIV-1 infection with advanced immunosuppression, oral thrush with odynophagia and dysphagia concerning for esophageal candidiasis, and a reactive rapid plasma reagin titer of 1:32 with retinal white dot lesions concerning for ocular syphilis. Computed tomography (CT) demonstrated diffuse right lower extremity soft tissue edema, extensive right inguinal, external iliac, and intrapelvic lymphadenopathy, bilateral axillary lymphadenopathy, and multiple bilateral pulmonary nodules. Punch biopsy of a right thigh lesion revealed KS with tumor cells positive for cluster of differentiation 31 (CD31), CD34, ERG, and human herpesvirus 8 (HHV-8), and an excisional lymph node biopsy demonstrated findings consistent with disseminated KS. Furthermore, cerebrospinal fluid (CSF) analysis confirmed neurosyphilis with a positive Venereal Disease Research Laboratory (VDRL). He was treated with bictegravir/emtricitabine/tenofovir alafenamide, trimethoprim-sulfamethoxazole prophylaxis, fluconazole, and intravenous penicillin G. The patient showed early clinical improvement with resolution of ocular symptoms and a declining HIV viral load following initiation of therapy and before discharge. This case highlights biopsy-proven KS as the presenting manifestation of previously undiagnosed advanced HIV, with unilateral limb lymphedema and pulmonary nodules suggesting disseminated disease. Additionally, our case underscores the need for early HIV testing in patients with recurrent mucocutaneous candidiasis and unexplained lymphedema, and for prompt evaluation of concomitant opportunistic and sexually transmitted infections.

The sacroiliac joint (SIJ) is a critical anatomic structure that connects the axial skeleton with the lower limbs. Compared with its adult counterpart, the pediatric SIJ exhibits unique anatomic features, and imaging evaluation may then present significant challenges due to overlapping features between normal developmental manifestations, anatomic variants, and true pathologic conditions. Two frequently observed developmental findings can resemble pathologic conditions: subchondral irregularities and subchondral flaring. These are commonly seen on MR images of the developing pelvis. A diverse range of anatomic variations has been documented in both the cartilaginous and ligamentous components of the SIJ. Though overall innocuous, some variations are linked to mechanical overload and pain. True sacroiliitis can arise from inflammatory, infectious, or traumatic causes. Inflammatory conditions may exhibit similar imaging characteristics and are best differentiated through MRI. The presence of unilateral sacroiliitis should prompt consideration of an infectious cause, with imaging indicators such as capsular edema and abscess formation suggesting infection. Traumatic injuries to the SIJ are uncommon in children and usually occur in the context of high-energy trauma. Mechanical overload or repetitive stress in the pediatric population can result in bone marrow edema in the weight-bearing regions of the SIJ and, less commonly, in sacral stress fractures, most often involving the sacral ala. It is crucial to accurately differentiate these imaging features to avoid functional impairments, morbidity, and unnecessary interventions. The authors aim to enhance radiologists' understanding of the pediatric SIJ by examining its unique anatomic characteristics, key imaging features, and pertinent differential diagnosis. [©] RSNA, 2026 Supplemental material is available for this article.

Meningiomas are common intracranial tumors, but their slowly progressive and atypical presentations are frequently mistaken for peripheral neurologic, musculoskeletal, or ocular conditions. We describe a 60-year-old left-handed man who developed several months of progressive right-sided gait imbalance, proprioceptive deficits, intermittent binocular visual blurring, and late cognitive changes. Evaluations by podiatry, chiropractic care, physical therapy, and optometry initially failed to uncover the cause. Brain MRI eventually revealed a large left posterior parietal dural-based mass with classic meningioma features, marked vasogenic edema, mass effect, and midline shift. Gross-total resection confirmed a WHO grade 1 meningioma (Ki-67 index 15 %). This case emphasizes an atypical presentation with progressive unilateral gait dysfunction accompanied by proprioceptive loss, pyramidal signs, visual symptoms, or cognitive decline. Refractory treatments should prompt early neuroimaging, even after negative peripheral workups. It also highlights how specialty-specific anchoring bias can delay recognition of central nervous system lesions.

A 71-year-old woman receiving paclitaxel, carboplatin, and pembrolizumab for breast carcinoma developed severe diarrhea, followed by hypovolemic shock with generalized edema, raising suspicion of immune checkpoint inhibitor-related capillary leak syndrome. Dynamic scintigraphy was performed using intravenous technetium-99m-labeled human serum albumin combined with induced transient venous stasis. Baseline 3D CZT SPECT imaging showed symmetrical vascular activity. Cuff inflation induced a progressive unilateral increase in tracer uptake consistent with albumin extravasation, followed by incomplete washout. Volumetric leak imaging enabled precise localization of capillary leakage. This case illustrates the potential of 3D CZT-ring cameras for dynamic functional assessment of vascular permeability.

A 54-year-old woman presented with slowly progressive left facial asymmetry and jaw weakness over three years, without sensory disturbances or other cranial nerve deficits. Clinical examination revealed wasting of the left-sided muscles of mastication with preserved facial sensation. Magnetic resonance imaging demonstrated marked fatty atrophy involving the left temporalis, masseter, medial, and lateral pterygoid muscles, along with subtle contralateral fatty infiltration of the right medial pterygoid muscle, suggesting possible early subclinical involvement. Fat-suppressed and high-resolution MRI sequences demonstrated no active muscle edema, skull base lesion, or abnormality involving the cisternal segments of the trigeminal nerves. Electromyography supported chronic neurogenic denervation involving the left-sided muscles of mastication. Pure trigeminal motor neuropathy is an uncommon entity characterized by selective motor involvement of the mandibular division of the trigeminal nerve, most commonly presenting unilaterally. This case highlights the role of MRI in identifying characteristic chronic denervation changes, excluding secondary causes, and detecting subtle clinically occult contralateral abnormalities that may otherwise be overlooked. Early recognition of this rare neuropathy may help avoid unnecessary investigations and support appropriate clinical evaluation.

Purtscher-like retinopathy (PLR) is a rare, vision-threatening occlusive microvasculopathy. We report a rare case of unilateral PLR following the initiation of chemotherapy for recurrent cervical carcinoma. A 54-year-old female with recurrent carcinoma of the cervical vault presented with sudden, painless diminution of vision in the left eye (visual acuity: 2/60), five days post-initiation of chemotherapy with gemcitabine and bevacizumab. Fundus examination revealed multiple superficial hemorrhages, cotton wool spots, and Purtscher flecken with macular edema, initially diagnosed elsewhere as a combined central retinal artery and vein occlusion. Systemic laboratory workup was unremarkable. A diagnosis of chemotherapy-induced PLR secondary to localized thrombotic microangiopathy was established. The patient was managed conservatively with close oncological follow-up. Gemcitabine and bevacizumab can precipitate localized thrombotic microangiopathy leading to PLR. Precise funduscopic evaluation is essential to distinguish PLR from combined retinal vascular occlusions to prevent unnecessary interventions and guide appropriate multidisciplinary management.