Differential Diagnoses of Diseases Involving the Extrinsic Ocular Musculature – A Pictorial Essay

Introduction There are some inflammatory, infectious, and neoplastic diseases affecting the extrinsic orbital musculature (EOM) that present with pain, decreased visual acuity, and proptosis. Imaging is fundamental to the differential diagnoses of these diseases with similar clinical presentations. The present case series report has as main objective to illustrate and discuss the main pathologies that affect the orbit. Material and methods The present series of cases discusses the main pathologies that can affect the extraocular musculature that can be characterized by computed tomography (CT) or magnetic resonance imaging (MRI) using cases from our institution. Results and Discussion The present study compiled several cases of ophthalmopathy from our institution to illustrate and address some of these pathologies, such as orbital lymphoma, Grave disease, metastases, periorbital cellulitis, and idiopathic orbital inflammatory syndrome. The diseases are discussed according to the presentation of clinical cases with emphasis on the main imaging findings of each pathology. Conclusion Computed tomography and MRI can help in the diagnosis and follow-up of the diseases that affect the EOM. We must be conversant with the main characteristics of the pathologies presented in the present case series report, since such findings together with clinical data can confirm the diagnosis of these diseases or at least help to narrow the differential diagnoses.

Plasma Lipocalin 2 in Alzheimer’s disease: potential utility in the differential diagnosis and relationship with other biomarkers

Background Lipocalin-2 is a glycoprotein that is involved in various physiological and pathophysiological processes. In the brain, it is expressed in response to vascular and other brain injury, as well as in Alzheimer’s disease in reactive microglia and astrocytes. Plasma Lipocalin-2 has been proposed as a biomarker for Alzheimer’s disease but available data is scarce and inconsistent. Thus, we evaluated plasma Lipocalin-2 in the context of Alzheimer’s disease, differential diagnoses, other biomarkers, and clinical data. Methods For this two-center case-control study, we analyzed Lipocalin-2 concentrations in plasma samples from a cohort of n = 407 individuals. The diagnostic groups comprised Alzheimer’s disease (n = 74), vascular dementia (n = 28), other important differential diagnoses (n = 221), and healthy controls (n = 84). Main results were validated in an independent cohort with patients with Alzheimer’s disease (n = 19), mild cognitive impairment (n = 27), and healthy individuals (n = 28). Results Plasma Lipocalin-2 was significantly lower in Alzheimer’s disease compared to healthy controls (p < 0.001) and all other groups (p < 0.01) except for mixed dementia (vascular and Alzheimer’s pathologic changes). Areas under the curve from receiver operation characteristics for the discrimination of Alzheimer’s disease and healthy controls were 0.783 (95%CI: 0.712–0.855) in the study cohort and 0.766 (95%CI: 0.627–0.905) in the validation cohort. The area under the curve for Alzheimer’s disease versus vascular dementia was 0.778 (95%CI: 0.667–0.890) in the study cohort. In Alzheimer’s disease patients, plasma Lipocalin2 did not show significant correlation with cerebrospinal fluid biomarkers of neurodegeneration and AD-related pathology (total-tau, phosphorylated tau protein, and beta-amyloid 1-42), cognitive status (Mini Mental Status Examination scores), APOE genotype, or presence of white matter hyperintensities. Interestingly, Lipocalin 2 was lower in patients with rapid disease course compared to patients with non-rapidly progressive Alzheimer’s disease (p = 0.013). Conclusions Plasma Lipocalin-2 has potential as a diagnostic biomarker for Alzheimer’s disease and seems to be independent from currently employed biomarkers.

Case Report: Uterine Adenosarcoma With Sarcomatous Overgrowth and Malignant Heterologous Elements

A 46- year-old woman presented a uterine adenosarcoma originating in the lower uterine segment. The diagnosis was made in an endometrial biopsy and confirmed in the pathological examination of the complete surgical specimen, both identifying heterologous malignant elements. In addition, complementary immunohistochemical studies were performed. We reviewed the literature, illustrating the clinical and morphological characteristics and the differential diagnoses to be evaluated.

Have You Seen A Kaleidoscope? A Case of Visual Migraine Aura

This is a case of migraine, presenting with the interesting visual aura of a ‘kaleidoscope’: waves with flickering movements made up of a variety of colors (red, blue, green, yellow), commencing laterally and spreading superiorly in the visual field of the left eye. This description is quite similar to a fortification spectrum, which usually expands and spreads in a C-shape fashion over one side of the visual field. Several different possible pathophysiological explanation are shared as well as the common differential diagnoses. In the work up of a patient with visual aura migraine, a comprehensive and detailed history is important, together with the appropriate investigations, in order not to miss any serious syndromes, including stroke syndromes and epilepsy.

Herpes Vegetans, an atypical herpes lesion in HIV patient: a case report

Herpes vegetans is a rare form of Herpes simplex virus (HSV) infection in immunocompromised patients that clinically presents as a verrucous and hypertrophic lesion. In this case, we present a 36- year-old man with exophytic verrucous masses in the genital area that was initially suspected as a malignancy. Difficulty to properly diagnose the patient resulted in a few failed attempts at treating the lesion. After excluding other differential diagnoses, the atypical lesion proved to be caused by vegetative herpes infection due to a good response to HSV therapy. Reevaluation of biopsy also showed signs of HSV etiology. Atypical presentation of herpes simplex in immunocompromised patients still proves to be a challenge to diagnose and treat. Proper clinical identification and workup are needed to diagnose and to choose proper regiments

Noninfectious complications of hematopoietic cell transplantation

Noninfectious lung diseases contribute to nonrelapse mortality. They constitute a spectrum of diseases that can affect the parenchyma, airways, or vascular pulmonary components and specifically exclude cardiac and renal causes. The differential diagnoses of these entities differ as a function of time after hematopoietic cell transplantation. Specific diagnosis, prognosis, and optimal treatment remain challenging, although progress has been made in recent decades.

Global Assessment of IRF8 as a Novel Cancer Biomarker

Interferon regulatory factor 8 (IRF8) is a member of the IRF family that is specific to the hematopoietic cell and is involved in regulating the development of human monocytic and dendritic-lineage cells, as well as B cells. Since its utility as a sensitive and specific monoblast marker in the context of acute monocytic leukemias has been recently demonstrated, we hypothesized that it may also be useful as a novel immunohistochemical marker in myeloid sarcomas and blastic plasmacytoid dendritic cell neoplasms (BPDCN) with respect to their differential diagnoses. In this retrospective study, we analyzed the IHC expression pattern of IRF8 in 385 patient samples across 30 types of cancers, referenced to their mRNA expression data available through TCGA. In addition, we assessed IRF8 in 35 myeloid sarcomas, and 13 BPDCNs. Twenty-four of 35 cases of myeloid sarcomas (68.5%) showed positivity for IRF8, with six cases (17.1%) demonstrating IRF8 expression in the absence of CD34 and MPO. All 13 of 13 BPDCNs (100%) showed strong uniform expression of IRF8 and was occasionally more definitive than CD123. IRF8 was negative in all desmoplastic small round cell tumors, Ewing sarcomas, synovial sarcomas, and undifferentiated pleomorphic sarcomas, as well as all epithelial malignancies tested except for 2 triple negative breast cancers that showed subset weak staining. In conclusion, IRF8 is a novel marker helpful in identifying extranodal hematopoietic tumors that can otherwise be difficult to diagnose given the broad differential diagnoses and frequent loss of more common lineage-defining markers.

Innocuous presentation of ameloblastic carcinoma

Ameloblastic carcinoma is a rare malignant odontogenic neoplasm that exhibits diverse clinical and radiological presentations. In fact there are several differential diagnoses during histopathological evaluation too. Lack of adequate reports could not establish the predominant demographic, clinical and radiological presentations. For the same reasons, the role of adjuvant radiotherapy and chemotherapy is also unsubstantiated yet. This case discusses the innocuous clinical and radiological presentation of ameloblastic carcinoma in a 55-year-old man where the diagnostic confirmation was achieved through histopathological evaluation. The differential diagnoses, treatment and follow-up details of this case are discussed in light of the previous published case reports and systematic reviews of case reports in an attempt to increase the sensitisation among dentists towards ameloblastic carcinoma.

Subchondral insufficiency fracture of the knee: review of current concepts and radiological differential diagnoses

Subchondral insufficiency fracture of the knee (SIFK) is a common cause of knee joint pain in older adults. SIFK is a type of stress fracture that occurs when repetitive and excessive stress is applied to the subchondral bone. If the fracture does not heal, the lesion develops into osteonecrosis and results in osteochondral collapse, requiring surgical management. Because of these clinical features, SIFK was initially termed “spontaneous osteonecrosis of the knee (SONK)” in the pre-MRI era. SONK is now categorized as an advanced SIFK lesion in the spectrum of this disease, and some authors believe the term “SONK” is a misnomer. MRI plays a significant role in the early diagnosis of SIFK. A subchondral T2 hypointense line of the affected condyle with extended bone marrow edema-like signal intensity are characteristic findings on MRI. The large lesion size and the presence of osteochondral collapse on imaging are associated with an increased risk of osteoarthritis. However, bone marrow edema-like signal intensity and osteochondral collapse alone are not specific to SIFK, and other osteochondral lesions, including avascular necrosis, osteochondral dissecans, and osteoarthritis should be considered. Chondral lesions and meniscal abnormalities, including posterior root tears, are also found in many patients with SIFK, and they are considered to be related to the development of SIFK. We review the clinical and imaging findings, including the anatomy and terminology history of SIFK, as well as its differential diagnoses. Radiologists should be familiar with these imaging features and clinical presentations for appropriate management.