Osteosarcoma
Overview Definition Osteosarcoma is a primary malignant tumor of the bone characterized by the production of osteoid or immature bone by the tumor cells. Epidemiology Etiology Pathophysiology and Clinical Presentation Pathophysiology Clinical presentation Diagnosis History Physical exam Laboratory studies Imaging Biopsy Musculoskeletal Tumor Society (MSTS) staging Management Chemotherapy Surgery Radiation Prognosis Differential Diagnosis References
Septic Arthritis
Epidemiology and Etiology Epidemiology Etiology The majority of septic arthritis infections are monomicrobial. Common organisms include: Risk factors Table: Most common organisms in septic arthritis, based on some notable underlying risk factors Risk factors Infectious agents No specific risk factor S. aureus Prosthetic joint replacement S. aureus (particularly MRSA) S. epidermidis (creates biofilms on prosthetics) […]
Henoch-Schönlein Purpura
Overview Definition Henoch-Schönlein purpura (HSP) is an immunoglobulin A (IgA)-mediated small-vessel vasculitis. Epidemiology Most common vasculitis in children 90% of cases occur in children 3–15 years of age. 20/100,000 in children versus 5/100,000 in adults More prevalent in whites Men > women (1.2–1.8:1) Rare in the summer months Etiology Multifactorial: genetic susceptibility and environmental triggers […]
Carcinoid Tumors and Syndrome
Overview Definition Carcinoid tumor is a neuroendocrine tumor arising from enterochromaffin cells, typically in the GI and bronchopulmonary tracts. Epidemiology Etiology Mnemonic The rule of 1/3s can be used to recall the characteristics of carcinoid tumors: Pathophysiology Carcinoid tumors Biological behavior: Classification based on embryonic origin: Carcinoid syndrome Clinical Presentation Symptoms of primary tumor Carcinoid […]
Primary Amenorrhea
Overview Definition Primary amenorrhea is defined as: Normal physiology Hormones of the hypothalamic–pituitary–ovarian (HPO) axis and all relevant anatomy must be present and functioning in order for a girl to get her first menses. Etiology and Pathophysiology Hypothalamic and pituitary etiologies Ovarian/gonadal etiologies Uterine and vaginal etiologies Other hormonal etiologies Clinical Presentation and Diagnosis Presentation […]
Thrombotic Thrombocytopenic Purpura
Overview Definition Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy caused by deficiency of ADAMTS-13, a von Willebrand factor (VWF) cleaving protease. Epidemiology Annual incidence: 3 cases per million in the United States (rare) Woman:man ratio is 2:1. More common in African Americans Affects adults predominantly: Average age: 41 years old Age range: 9–78 years […]
Carotid Artery Stenosis
Overview Definition Carotid artery stenosis is a narrowing of the common and internal carotid arteries (ICAs) secondary to atherosclerosis. Epidemiology Etiology Pathophysiology Carotid stenosis can cause symptoms from a state of low flow or embolization. Low flow results from progressive narrowing of the carotid artery: Embolization: Clinical Presentation Asymptomatic carotid artery stenosis: carotid atherosclerosis without […]
Necrotizing Enterocolitis
Overview Definition Necrotizing enterocolitis (NEC) is an intestinal inflammatory condition associated with focal or diffuse ulceration and necrosis that primarily affects the terminal ileum and colon. Epidemiology Etiology Pathophysiology and Clinical Presentation Pathophysiology Clinical presentation Diagnosis The diagnosis of NEC is made primarily by imaging. Abdominal X-ray Abdominal X-ray is the method of choice to […]
Erectile Dysfunction
Overview Definition Erectile dysfunction (ED) is the recurrent failure to achieve or maintain consistent rigid penile erection for satisfactory sexual intercourse. Clinical importance: Epidemiology Globally, at least 150 million men suffer from ED: Prevalence of ED is closely related to increased age and presence of other systemic comorbidities. Etiology Erectile dysfunction is a multifactorial disease […]
Sarcoidosis
Overview Definition Sarcoidosis is a multisystem inflammatory disease characterized by the formation of noncaseating granulomas that are most likely caused by a cell-mediated immune reaction of unknown etiology. Pulmonary sarcoidosis is a restrictive interstitial lung disease with granuloma formation in the: Extrapulmonary sarcoidosis is characterized by granuloma formation in: Sarcoidosis may be acute or chronic: […]