Carlstrom, Lucas P.

Abstract MicroAVMs (microarteriovenous malformation) are arteriovenous shunts with a nidus smaller than 1 centimeter. 1 They are typically diagnosed after hemorrhage. When the nidus is very small, diagnosis can be challenging even on catheter angiography and careful examination of the arterial and capillary phases is required to identify the early shunt. Because of the very small size, identification and localization of the actual AV shunt can be problematic during surgical exploration. Advances in frameless stereotactic neuronavigation and the introduction of intraoperative indocyanine green (ICG) fluorescein provide useful adjuncts in the surgical treatment of these relatively uncommon lesions. In this video, we present 2 cases which document the value of intraoperative ICG fluorescein as well as some of the surgical pitfalls in the treatment of these lesions.

Abstract BACKGROUND AND IMPORTANCE Transverse ligament cysts (TLC) are rare, surgically complex lesions arising posterior to the odontoid process of C2. Direct compression of the cervicomedullary junction is a devastating consequence of untreated lesions. We report the first case of spontaneous TLC regression without surgical intervention. CLINICAL PRESENTATION A 75-yr-old woman presented to an outside hospital with acute episodes of left face and upper extremity numbness. Magnetic resonance imaging (MRI) demonstrated a well-circumscribed 5.8 mm cystic mass at the atlantoaxial junction, posterior to the odontoid process, most consistent with a TLC. She presented to our institution 1 yr later with symptoms of progressive occipital neuralgia seeking surgical treatment. No evidence of cervical myelopathy was identified on clinical examination. Repeat MRI showed near doubling of the cyst, with no brainstem edema. The patient elected for surveillance of the cyst with a transforaminal steroid injection at C1-C2 for her occipital neuralgia. One year later, symptoms of occipital neuralgia had resolved and she remained neurologically intact; MRI of the cervical spine showed near complete involution of the cyst. CONCLUSION Symptomatic TLCs are often managed with surgical decompression and, in selected cases, fusion with good functional outcome. However, these interventions carry high risk of postoperative morbidity, particularly in the elderly. Conservative surveillance is rarely reported as a viable option. We present the first case of spontaneous TLC regression in the absence surgery or neck bracing. In select patients without acute myelopathy, clinical and radiographic surveillance may be considered for the management of TLCs.

OBJECTIVENelson-Salassa syndrome (NSS) is a rare consequence of bilateral adrenalectomy (ADX) for refractory hypercortisolism due to Cushing disease (CD). Although classically defined by rapid growth of a large, invasive, adrenocorticotropin hormone (ACTH)–secreting pituitary tumor after bilateral ADX that causes cutaneous hyperpigmentation, visual disturbance, and high levels of ACTH, clinical experience suggests more variability.METHODSThe authors conducted a retrospective chart review of all patients 18 years and older with a history of bilateral ADX for CD, adequate pituitary MRI, and at least 2 years of clinical follow-up. Statistical tests included Student's t-test, chi-square test, Fisher's exact test, multivariate analysis, and derived receiver operating characteristic curves.RESULTSBetween 1956 and 2015, 302 patients underwent bilateral ADX for the treatment of hypercortisolism caused by CD; 88 had requisite imaging and follow-up (mean 16 years). Forty-seven patients (53%) had radiographic progression of pituitary disease and were diagnosed with NSS. Compared with patients who did not experience progression, those who developed NSS were significantly younger at the time of CD diagnosis (33 vs 44 years, p = 0.007) and at the time of bilateral ADX (35 vs 49 years, p = 0.007), had larger tumors at the time of CD diagnosis (6 mm vs 1 mm, p = 0.03), and were more likely to have undergone external-beam radiation therapy (EBRT, 43% vs 12%, p = 0.005). Among NSS patients, the mean tumor growth was 7 mm/yr (SE 6 mm/yr); the median tumor growth was 3 mm/yr. Prevalence of pathognomonic symptoms was low; the classic triad occurred in 9%, while hyperpigmentation without visual field deficit was observed in 23%, and 68% remained asymptomatic despite radiographic disease progression. NSS required treatment in 14 patients (30%).CONCLUSIONSNSS is a prevalent sequela of CD after bilateral ADX and affects more than 50% of patients. However, although radiological evidence of NSS is common, it is most often clinically indolent, with only a small minority of patients developing the more aggressive disease phenotype characterized by clinically meaningful symptoms and indications for treatment. Young age at the time of CD diagnosis or treatment with bilateral ADX, large tumor size at CD diagnosis, and EBRT are associated with progression to NSS and may be markers of aggressiveness.