18 F-FDG PET/CT Findings of Leptomeningeal Metastasis in Nasopharyngeal Carcinoma.

ABSTRACT: Nasopharyngeal carcinoma (NC) is an epithelial tumor with distinctive prevalence in East and Southeast Asia. Most patients with NC only experience regional metastasis. In cases of distant metastasis, prognosis is grim. Leptomeningeal spread of the disease is a rare occurrence, which is sparsely described in the literature. We present a case of a 33-year-old man with a history of high-grade NC with leptomeningeal metastasis. Initial MRI lumbar spine demonstrated subtle findings consistent with leptomeningeal disease. These findings are easily discernible on 18 F-FDG PET/CT.

Clavicular Metastasis as an Initial Presentation of Papillary Thyroid Cancer.

OBJECTIVE: We present the case of a 44-year-old man with a large neck mass to highlight the unique presentation of papillary thyroid carcinoma (PTC) metastatic to the clavicle. METHODS: We reviewed the medical record for a detailed history and physical examination findings. Our radiology colleagues examined the diagnostic imaging studies performed. The pathology team reviewed the neck mass biopsy and the confirmatory surgical pathology after total resection of the mass. RESULTS: A 44-year-old man presented with an enlarging neck mass. Initial X-rays revealed a large soft tissue density mass that extended to the midline of the right clavicle. A neck ultrasound established a 5.4 × 3.6 cm mass with increased vascularity and calcification extending from the thyroid. A CT scan noted the extension of the mass into the adjacent sternoclavicular junction with osteolysis of the middle third of the clavicle and the superior aspect of the sternal body. Fine-needle aspiration revealed a thyroid neoplasm with follicular features and positive immunostaining consistent with thyroid carcinoma. The patient underwent a composite resection of the tumor, including a segmental osteotomy of approximately two-thirds of the medial clavicle. The pathology report confirmed PTC with extrathyroidal extension and clavicle involvement (staged pT4a pN0), with further genomic findings showing positive KRAS mutation. CONCLUSION: Clavicular metastasis from differentiated thyroid cancer is rare. While the prognosis is generally favorable, various factors, including age greater than 45 years, poor differentiation, follicular thyroid carcinoma, Hurthle cell variant, and extrapulmonary metastasis, have typically been associated with poorer cancer-specific survival.

Symptomatic Pituitary Metastasis as Initial Manifestation of Renal Cell Carcinoma: Case Report and Review of Literature.

Metastasis to the pituitary gland is extremely rare (∼2% of sellar masses). Clinical, biochemical, and radiologic characteristics of pituitary metastasis are poorly defined and can be difficult to diagnose before surgery. We present an unusual case with pituitary metastasis as the first manifestation of renal cell carcinoma (RCC). A 70-year-old male presented with acute onset of weakness, dizziness, diplopia, and progressively worsening headache. The initial CT head revealed a heterogeneous sellar mass measuring 2.8 × 1.9 × 1.7 cm. A follow-up MRI showed the sellar mass invading the right cavernous sinus. The presumptive diagnosis was a pituitary macroadenoma. Physical examination revealed bilateral 6th cranial nerve palsy and episodes of intermittent binocular horizontal diplopia. Hormonal testing noted possible secondary adrenal insufficiency (AM serum cortisol: 3.3 mcg/dL, ACTH: 8 pg/mL), secondary hypothyroidism (TSH: <0.01 mIU/L, FT4: 0.7 ng/dL), secondary hypogonadism (testosterone: 47 ng/dL, LH: 1.3 mIU/mL, and FSH: 2.3 mIU/mL), and elevated serum prolactin (prolactin: 56.8 ng/ml, normal: 4.0-15.2 ng/ml). IGF-1 level was normal at 110 ng/mL (47-192 ng/mL). The patient was discharged on levothyroxine and hydrocortisone therapy with plans for close surveillance. However, his condition worsened over the next three months, and he was subsequently readmitted with nausea, vomiting, and hypernatremia secondary to diabetes insipidus. Repeat MRI pituitary showed an interval increase in the size of the sellar mass with suprasellar extension and a new mass effect on the optic chiasm. The sellar mass was urgently resected via a trans-sphenoidal approach. The tumor was negative for neuroendocrine markers and pituitary hormone panel, ruling out the diagnosis of pituitary adenoma and triggered workup for metastatic renal cell carcinoma, clear cell type. The diagnosis of renal cell carcinoma was confirmed by the diffuse and strong staining for renal cell carcinoma markers (Pax-8, RCC-1, and CD10). A follow-up CT scan noted large right renal mass measuring 11 × 10 × 11 cm. The patient underwent a cytoreductive robotic right radical nephrectomy for WHO/ISUP histologic grade II clear cell RCC, stage pT2b pNX pM1. He subsequently received fractionated stereotactic radiotherapy to the pituitary gland. He is presently stable with no radiological evidence of progression or new intracranial disease on subsequent imaging. Pituitary metastasis most commonly occurs from breast, lung, or gastrointestinal tumors but also rarely from renal cell carcinoma. Biochemical findings such as panhypopituitarism, acute clinical signs such as headache, visual symptoms, and diabetes insipidus and interval increase in sellar mass in a short time interval should raise suspicion for sellar metastasis.

Brainstem Diffuse Axonal Injury and Consciousness.

BACKGROUND: Severe traumatic brain injuries (TBI), commonly due to motor vehicle accidents may cause death and long-term disability especially when the acceleration-deceleration force on the brain is massive. This may cause shearing of the axonal connections within the cerebral cortex and brainstem in a process referred to as diffuse axonal injury (DAI). Extensive DAI has been postulated to be a poor prognostic indicator for neurological recovery. In our institution, several patients with Grade 3 DAI were observed to recover and achieve neurological outcomes greater than expected given the presence of brainstem injury. METHODS: MRI studies from 100 patients admitted to a large tertiary trauma center for TBI were retrospectively analyzed by two fellowship-trained neuroradiologists. The size of DAI lesions, location of injury within the brainstem, and the number of discrete DAI lesions were measured and recorded. Glasgow Coma Scale (GCS) on arrival and at discharge was noted, as well as the presence of other neurological injuries. RESULTS: Of 20 patients initially noted to have DAI with lesions of the brainstem, eight of them were discharged with Glasgow Coma Scale (GCS) of 14-15. The 12 patients discharged with reduced consciousness (average GC 7.1) demonstrated a greater number of larger lesions, with a predilection for the dorsal pons. CONCLUSION: These results suggest that large, numerous pontine lesions may indicate worse neurological outcomes in patients with these findings.

Necrotic Primary Central Nervous System Lymphoma in an Immunocompetent Patient: A Case Report and Literature Review.

Primary lymphoma that arises de novo from the central nervous system (CNS) is most commonly a non-Hodgkin's B-cell lymphoma and by definition lacks the presence of disease outside the CNS. It demonstrates a characteristic imaging appearance on computed tomography (CT) and magnetic resonance imaging (MRI) exams related to its inherent hypercellularity. On CT, primary CNS lymphoma (PCNSL) demonstrates a hyperdense appearance; on MRI, it commonly demonstrates restricted water diffusion on diffusion-weighted sequences and homogeneous enhancement on post-contrast sequences. We present a case of primary CNS lymphoma in an immunocompetent patient with progressive necrosis and loss of restricted diffusion on diffusion-weighted imaging (DWI) with an atypical enhancement pattern. We further provide a review of the literature regarding the CT and MRI appearance of primary CNS lymphoma and discuss the role of immune status in determining the imaging characteristics of this disease process.

Tectorial membrane injury in adult and pediatric trauma patients: a retrospective review and proposed classification scheme.

BACKGROUND AND PURPOSE: Traumatic tectorial membrane injuries have different radiologic presentations in adult versus pediatric patients. The purpose of this study was to identify and classify the different types of tectorial membrane injuries that occur in the adult and pediatric populations. MATERIALS AND METHODS: Patients who suffered tectorial membrane injury were identified retrospectively using the keywords 'tectorial membrane," "craniocervical ligament tear/injury," and "atlanto-occipital dissociation" included in radiology reports between 2012 and 2018 using Nuance mPower software. All relevant imaging studies were reviewed by two certificates of additional qualification-certified neuroradiologists. Detailed descriptions of injuries were recorded along with any relevant additional findings, including clinical history. RESULTS: Ten adults and six pediatric patients were identified with acute traumatic injuries of the tectorial membrane. Ninety percent of the adult patients sustained complete disruptions inferior to the clivus, or subclival, with 22% of tears at the level of the basion and 78% at the level of the odontoid tip. In contrast, 83% of pediatric patients suffered a stripping injury of the tectorial membrane located posterior to the clivus, or retroclival. Stretch injuries of the tectorial membrane were identified in 10% of adults and 17% of pediatric patients. The juvenile-type injury, which causes retroclival epidural hematoma, was determined to preferentially occur in patients less than or equal to 14 years of age with a high level of statistical significance (p value = 0.0014). CONCLUSIONS: A classification system for tectorial membrane injuries is proposed based on this data: type 1-retroclival stripping injury (more common in pediatric patients); type 2a-subclival disruption at the basion and type 2b-subclival disruption at the odontoid (both more common in adult patients); and type 3-thinning of the tectorial membrane.

Desmoplastic fibroblastoma of the left upper arm.

An elderly female patient presented to the clinic with a several-week history of a mass in her left upper arm that was tender to the touch. The mass was initially thought to be a schwannoma of the left radial nerve based on imaging and was surgically removed. The pathology report revealed an uncommon diagnosis of desmoplastic fibroblastoma.

A Case Report of Mikulicz Syndrome.

Mikulicz Syndrome (MS) is a rare chronic condition characterized by the abnormal enlargement of glandular tissue in the head and neck. Patients usually present with enlarged lacrimal and parotid glands. While this can be a benign self-limiting condition, other complex systemic diseases, such as sarcoidosis, may represent other underlying etiologies. We present a case of MS in a patient with a history of Crohn's disease.