Differentiation of intracranial Rosai-Dorfman histiocytosis from meningioma using MR perfusion.

Intracranial Rosai-Dorfman disease may be indistinguishable from meningioma. This distinction is essential, as they are treated very differently. We present two cases where perfusion imaging helped make this distinction, allowing one to be treated successfully without craniotomy. Perfusion imaging may be a powerful adjunct in cases where RDD mimics meningioma.

Idiopathic Terminal Ileal Ulceration Mimicking Crohn's in the Setting of Antiretroviral Therapy Initiation.

Antiretroviral therapy (ART) has precipitously decreased the morbidity associated with human immunodeficiency virus but can unmask and exacerbate opportunistic infections and autoimmune diseases. Various diseases have been reported in association with ART initiation, but there is scant literature describing inflammatory colitis in the setting of ART initiation. We present a 39-year-old man with chronic untreated human immunodeficiency virus and central nervous system toxoplasmosis who developed persistent diarrhea after initiation of ART. A comprehensive infectious workup was negative. Computed tomography demonstrated terminal ileum enteritis, which was confirmed by colonoscopy. Biopsy of the terminal ileum revealed fibrinous exudate and granulation tissue.

Orbital cellulitis, sinusitis and intracranial abnormalities in two adolescents with COVID-19.

We review two cases of adolescents with orbital cellulitis, sinusitis and SARS- CoV-2 infection presenting to emergency departments within a 24 hour period. SARS-CoV-2 samples obtained within 24 hours were positive, supporting prior infection despite relatively limited early symptoms of COVID-19. Unusual clinical and radiographic characteristics included hemorrhagic abscess with blood of varying age in the first, intracranial epidural abscess in the second, radiographic signal consistent with hemorrhagic or thrombotic phenomena, retro-maxillary antral fat changes, and meningeal enhancement or extension in both cases. Radiographic findings thereby mimic fungal infection, although final cultures and ancillary investigation for allergic and invasive fungal disease have remained negative. These cases highlight two unusual orbital presentations of cellulitis occurring in the context of SARS-CoV-2 co-infection.

Myoepithelioma of the Lower Eyelid.

A 59-year-old woman presented with a 4-year history of a progressively growing, subcutaneous, painless, left lower eyelid mass with associated swelling and discomfort. Excisional biopsy established the diagnosis of a myoepithelioma, a tumor which, to the authors' knowledge, has not been previously reported in the lower eyelid.

Lacrimal Gland Ductal Cyst Complicated by Abscess Formation.

A 52-year-old woman with a 7-month history of a left lateral upper eyelid nodule presented with an acute, 1-day history of left upper eyelid swelling and erythema associated with chemosis, epiphora, and pain. Magnetic resonance (MR) imaging revealed a well-circumscribed cystic mass indistinguishable from the left lacrimal gland containing a fluid-fluid level. Surgery confirmed an abscess within the lacrimal gland; histopathologic examination revealed a dilated lacrimal duct with an inflammatory exudate within the lumen. This report details one of the few reported cases of an acute lacrimal gland ductal cyst abscess and, to the authors' knowledge, the first with MR images.

Orbital Lymphangioma Confined to an Extraocular Muscle.

A 48-year-old woman presented with a 1-year history of an enlarging, nontender right lateral intrapalpebral mass overlying the insertion of the right lateral rectus muscle, associated with a 3-month history of worsening right orbital pain and retrobulbar headaches. MR imaging revealed an isointense right orbital mass contained entirely within the right lateral rectus muscle and indistinguishable from it. Transconjunctival biopsy established the diagnosis of lymphangioma. To the authors' knowledge, this case represents the first reported orbital lymphangioma contained entirely within an extraocular muscle.

Intravascular papillary endothelial hyperplasia of the periocular region.

Intravascular papillary endothelial hyperplasia (IPEH) is a benign vascular lesion, typically found in the skin, consisting of a papillary proliferation of endothelial cells intimately related to a thrombus; it appears to be a rare variant of an organizing process. IPEH very rarely develops in the periocular region, with fewer than 20 such cases currently reported in the English language literature. We describe one of the largest ever case series of this uncommon lesion occurring in the periocular region and discuss its clinical features, imaging characteristics, and surgical management.

Chronic, Symptomatic Orbital Inflammation Resulting From Retained Bone Wax.

A 58-year-old man presented with a 9-month history of a chronically draining surgical wound and low-grade periorbital inflammation following a right lateral orbitotomy. Imaging of the right orbit revealed a peculiar lesion in the right lateral orbit that was hypointense on both T1- and T2-weighted MRI with peripheral enhancement. Exploratory orbitotomy and biopsy established the diagnosis of a chronic foreign body inflammatory reaction to bone wax; symptoms resolved following evacuation of the retained foreign material.A 58-year-old man developed a chronic, symptomatic, inflammatory reaction to bone wax following a lateral orbitotomy; only once previously has symptomatic orbital inflammation following orbital surgery as a result of bone wax been reported.

Clinical and Magnetic Resonance Imaging Characteristics of Postfenestration Optic Nerve Sheath Pseudomeningoceles.

PURPOSE: The clinical significance of postoperative pseudomeningocele formation following optic nerve sheath fenestration (ONSF) has not been fully characterized. A literature review identifies 9 previously published cases the authors believe demonstrate pseudomeningocele formation and approximately 19 other similar findings that were either transient or less defined blebs. This study was undertaken to more clearly define the clinical, radiographic, and histopathologic features associated with this entity. METHODS: Sixteen-year, single-center, retrospective chart review of all ONSF cases performed by 2 surgeons. Clinical data, intracranial pressure, radiographic imaging, and histopathology of clinically detected pseudomeningoceles after ONSF were reviewed. RESULTS: Eighty-six eyes in 57 patients underwent ONSF (28 unilateral, 12 bilateral sequential, 17 bilateral simultaneous). Forty-nine of 57 patients had elevated intracranial pressure preoperatively (41 idiopathic intracranial hypertension, 4 venous thrombosis, 2 meningitis, 1 arteriovenous malformation, and 1 sarcoid). In 32 patients undergoing postoperative imaging, 4 eyes (4.7%) in 4 patients developed well-defined pseudomeningoceles, of which 3 were symptomatic and 2 required surgical revision. Each pseudomeningocele developed in the setting of elevated preoperative intracranial pressure (350, 360, 430, 500 mm H20). Magnetic resonance imaging and/or computed tomography revealed sharply demarcated fluid-filled sacs adjacent to the optic nerve. The contents of these sacs were hypointense on T1-weighted imaging, hyperintense on T2-weighting, variably enhanced with contrast, and hypointense on fluid attenuated inversion recovery, and were thus consistent with cerebrospinal fluid. Histopathologic analysis of one of these outpouchings demonstrated an acellular, fibrocollagenized lining consistent with pseudomeningocele. Three eyes in 3 additional patients had less well-defined findings on imaging interpreted as bleb-like or cyst-like change. CONCLUSIONS: Pseudomeningoceles following ONSF may be asymptomatic or may cause symptomatic orbital mass effect and rarely visual loss, amendable to surgical excision. Post-ONSF pseudomeningoceles are identified on computed tomography or magnetic resonance imaging to occur at the locations of fenestration sites and contain cerebrospinal fluid communicating with the subdural space that may act as a "filtration" bleb in some cases. Imaging findings may represent a spectrum spanning intraorbital cerebrospinal fluid leakage, partial walling off of bleb, or fully developed cysts. Resection of optic nerve pseudomeningoceles is considered in symptomatic cysts or eyes with papilledema that fails to improve.

Orbital Hobnail Hemangioma.

A 64-year-old woman presented with a 1 year history of progressive left proptosis and "blurry vision." Imaging studies revealed a left superior orbital mass distorting the optic nerve and superior rectus muscle. Excisional biopsy established the diagnosis of hobnail hemangioma. This report describes the first case of an orbital hobnail hemangioma, a lesion that more commonly presents in the dermis.

Myxofibrosarcoma of the maxillary sinus.

BACKGROUND: Myxofibrosarcoma (MFS) is a common sarcoma in the extremities of older individuals but is extremely uncommon in the head and neck region. Diagnosis may be challenging but is critical to the management of the patient. We discuss the radiographic and histopathologic characteristics of this destructive tumor. The distinguishing features of MFS and its differential diagnosis are reviewed to familiarize the managing otolaryngologist with this rare entity. METHODS: A 61-year-old woman presents with a 6-week history of severe left facial pain and left eye pain. Imaging demonstrates significant right and left-sided maxillary sinus opacification with destruction of the left maxillary sinus as well as the left medial and inferior orbital walls. RESULTS: Histopathologic examination revealed spindle and stellate tumor cells of variable cellularity in myxoid stroma with cellular pleomorphism consistent with MFS of intermediate-to high grade. The patient underwent resection of the left-sided lesion with orbital exenteration and repair of the defect with microvascular free flap followed by postoperative radiotherapy. CONCLUSION: MFS must be differentiated from other lesions with myxoid qualities. Histopathologic examination is required for definitive diagnosis. Management includes complete tumor excision with adequate tumor margins. Adjuvant postoperative radiotherapy should be considered for larger tumors with positive resection margins or lesions of intermediate-to-high grade.

Successful Treatment of Extensive Squamous Cell Carcinoma of the Conjunctiva and Upper Eyelid Skin With Topical Therapy Alone.

This study reports a case of extensive periocular squamous cell carcinoma of the conjunctiva, extending into the superior fornix, over the upper eyelid margin, and involving the superficial layers of the eyelid skin up to the eyebrow, that was successfully treated solely with topical therapy.

Derepression of hTERT gene expression promotes escape from oncogene-induced cellular senescence.

Oncogene-induced senescence (OIS) is a critical tumor-suppressing mechanism that restrains cancer progression at premalignant stages, in part by causing telomere dysfunction. Currently it is unknown whether this proliferative arrest presents a stable and therefore irreversible barrier to cancer progression. Here we demonstrate that cells frequently escape OIS induced by oncogenic H-Ras and B-Raf, after a prolonged period in the senescence arrested state. Cells that had escaped senescence displayed high oncogene expression levels, retained functional DNA damage responses, and acquired chromatin changes that promoted c-Myc-dependent expression of the human telomerase reverse transcriptase gene (hTERT). Telomerase was able to resolve existing telomeric DNA damage response foci and suppressed formation of new ones that were generated as a consequence of DNA replication stress and oncogenic signals. Inhibition of MAP kinase signaling, suppressing c-Myc expression, or inhibiting telomerase activity, caused telomere dysfunction and proliferative defects in cells that had escaped senescence, whereas ectopic expression of hTERT facilitated OIS escape. In human early neoplastic skin and breast tissue, hTERT expression was detected in cells that displayed features of senescence, suggesting that reactivation of telomerase expression in senescent cells is an early event during cancer progression in humans. Together, our data demonstrate that cells arrested in OIS retain the potential to escape senescence by mechanisms that involve derepression of hTERT expression.