Block 10 Bone And Arthritis - Pt.1

The presence of monosodium urate crystals in the joint aspirate indicates the deposition of uric acid crystals in the joint, which is a characteristic feature of gout. Gout is a form of arthritis that occurs due to the buildup of uric acid in the body, leading to the formation of crystals in the joints. This causes inflammation, pain, and swelling in the affected joints, commonly the big toe, ankle, or knee. Therefore, the diagnosis in this case is most likely to be gout.

Hormone replacement therapy (HRT) is the correct answer because the symptoms described in the question are consistent with osteoporosis, a condition characterized by bone loss and increased risk of fractures. Post-menopausal women are particularly susceptible to osteoporosis due to the decline in estrogen levels, which plays a crucial role in maintaining bone density. HRT, which involves the use of estrogen and sometimes progestin, can help prevent or slow down bone loss and reduce the risk of fractures in post-menopausal women. Therefore, if the woman had taken hormone replacement therapy, it could have potentially prevented or minimized the development of her symptoms.

Osteogenesis imperfecta is a genetic disorder characterized by brittle bones that are prone to fracture. The correct answer is "hereditary defect in synthesis of collagen" because collagen is a major component of bone tissue and is responsible for its strength and flexibility. In osteogenesis imperfecta, there is a defect in the production of collagen, leading to weak and fragile bones. This defect can be inherited from one or both parents and affects the body's ability to produce normal collagen, resulting in the symptoms seen in osteogenesis imperfecta.

The given scenario describes a 55-year-old man with painful hips bilaterally. The radiographs show joint space narrowing, osteophyte formation, and round radiolucent cystic zones in the subchondral bone of both femoral heads. These findings are characteristic of osteoarthritis, which is the degenerative joint disease typically associated with aging. Infectious arthritis is unlikely as there are no signs of infection mentioned. Psoriatic arthritis, ankylosing spondylitis, and rheumatoid arthritis usually present with different clinical and radiographic features. Therefore, osteoarthritis is the most appropriate diagnosis in this case.

Rickets is a disease that is characterized by failure to mineralize within the zone of provisional calcification. This means that the process of mineralization, which is necessary for the proper development and strengthening of bones, is impaired in individuals with rickets. This condition is typically caused by a deficiency in vitamin D, calcium, or phosphate, which are essential for bone health. Rickets can lead to skeletal deformities, weak and brittle bones, and growth retardation in children.

Rheumatoid arthritis usually has its origin in small peripheral joints. This means that the condition typically starts in joints such as those in the hands, wrists, feet, and ankles. Rheumatoid arthritis is an autoimmune disease that causes inflammation and damage to the lining of these joints. It can eventually spread to other joints in the body, but it commonly begins in the smaller joints.

The symptoms described in the question, including vague bony pains and a change in the fit of his hat, along with the observation of warm skin over a painful bony area, are consistent with Paget's disease. Paget's disease is a chronic disorder that affects the normal remodeling of bone, leading to weakened and enlarged bones. It can cause bone pain, deformities, and changes in hat size due to skull involvement. The warm skin over the affected area suggests increased blood flow and inflammation, which is commonly seen in Paget's disease.

In osteopetrosis, there is a defect in bone resorption leading to increased bone density. This can result in decreased bone marrow space and impaired hematopoiesis. As a compensatory mechanism, hematopoiesis occurs in extramedullary sites, such as the liver and spleen. Splenomegaly is commonly seen in osteopetrosis due to the increased workload of extramedullary hematopoiesis in the spleen. Therefore, extramedullary hematopoiesis is the most likely explanation for the presence of splenomegaly in a patient with osteopetrosis.

This happened because something else was "red hot and swollen" at splash bash

Brown tumors of bone are a rare complication of hyperparathyroidism, a condition characterized by excessive production of parathyroid hormone (PTH). Hyperparathyroidism leads to increased levels of calcium in the blood, which can cause the formation of bone tumors. These tumors are called brown tumors due to their characteristic brown color. They are not true tumors but rather a reactive process in response to the hormonal imbalance. Brown tumors can occur in any bone but are most commonly found in the long bones, ribs, and pelvis. Treatment involves addressing the underlying hyperparathyroidism and restoring normal calcium levels.

The appearance of multiple "punched out" lesions of bone on radiography is highly suggestive of multiple myeloma. Multiple myeloma is a type of cancer that affects plasma cells in the bone marrow, leading to the formation of these characteristic lesions. These lesions are caused by the destruction of bone tissue by the abnormal plasma cells. Other conditions such as osteogenic sarcoma, malignant giant cell tumor of bone, osteogenesis imperfecta, and Paget's disease may also cause bone lesions, but the presence of multiple punched out lesions is most commonly associated with multiple myeloma.

Plexiform neurofibromas are indeed associated with Neurofibromatosis Type 1. Neurofibromatosis Type 1 is a genetic disorder characterized by the growth of tumors along the nerves, and plexiform neurofibromas are a specific type of tumor that commonly occurs in individuals with this condition. These tumors can cause various complications and symptoms depending on their location and size. Therefore, option B is the correct statement regarding neurofibromas.

The correct answer is "Accumulation of amyloid b peptide within CNS neurons." This is because the presence of numerous neurofibrillary tangles and neuritic plaques in the brain, along with the patient's symptoms of dementia, are characteristic of Alzheimer's disease. In Alzheimer's disease, there is an abnormal accumulation of amyloid beta peptide, which forms plaques, and tau protein, which forms tangles, within the neurons of the central nervous system. This accumulation leads to neuronal dysfunction and ultimately results in the progressive cognitive decline seen in dementia.

The patient's presentation of symmetric proximal muscle weakness, light-purple skin rash over the upper eyelids, and perifascicular atrophy on muscle biopsy is consistent with dermatomyositis. Dermatomyositis is an autoimmune inflammatory myopathy that primarily affects the muscles and skin. The characteristic skin rash, known as heliotrope rash, is often seen in dermatomyositis. This condition typically affects women in their 40s to 60s and can be associated with other systemic symptoms such as fatigue, joint pain, and lung involvement.

The positive direct Coombs test suggests that there are antibodies coating the patient's red blood cells. This is most likely due to an incompatible blood transfusion, where the patient's immune system recognizes the transfused blood as foreign and produces antibodies against it. This can lead to hemolysis and anemia. Sickle cell disease, hereditary spherocytosis, paroxysmal nocturnal hemoglobinemia, and drug-sensitive hemolytic anemia do not typically cause a positive Coombs test in the context of a blood transfusion.

Ewings Sarcoma:
a primitive neuroectodermal tumor (PNET) of children under 20 yrs. Diaphysis, invades cortex & raises the periosteum --> onion-skin layers of new bone around the diaphysis (# x-ray sign)
sheets of small round cells (may resemble lymphoma or neuroblastoma)& occasional Homer-Wright pseudorosettes
may be mistaken for acute osteomyelitis
combined therapy --> 75% 5-year survival

The patient's symptoms of rapidly progressive dementia, myoclonus, and ataxia, along with the presence of spongiform degeneration in the cerebral cortex, basal ganglia, and cerebellum, are characteristic of Creutzfeldt-Jakob Disease (CJD). CJD is a rare, degenerative neurological disorder caused by abnormal proteins called prions. It leads to the destruction of brain tissue and rapidly progressive neurological symptoms. The other options, such as Alzheimer's disease, arbovirus encephalitis, Huntington's disease, and progressive multifocal leukoencephalopathy, do not match the specific clinical and pathological findings described in the case.

The patient's symptoms of weakness starting distally and rapidly ascending to involve proximal muscle groups, as well as the involvement of respiratory muscles requiring ventilatory support, are consistent with Guillain Barre Syndrome. Plasmapheresis is a treatment commonly used for this condition, and the fact that the patient completely recovered within three months further supports this diagnosis.

The patient's symptoms of involuntary jerky movements, progressive dementia, and a positive family history suggest a neurodegenerative disorder. The most likely diagnosis is Huntington's disease, which is characterized by marked atrophy of the caudate nucleus with neuronal loss and gliosis. This is confirmed by the patient's age at onset and the fact that his father also had the same disorder. Examination of the patient's brain at autopsy would reveal these characteristic changes in the caudate nucleus.

The presence of lytic lesions in the lumbar back and pelvis, along with elevated alkaline phosphatase, suggests a metastatic carcinoma. Metastatic carcinoma refers to the spread of cancer from its primary site to other parts of the body. The normal serum calcium, serum protein, and peripheral blood smears indicate that there is no involvement of the bone marrow or multiple myeloma. Osteoporosis is a condition characterized by low bone density and is unlikely to present with discrete lytic lesions. Osteosarcoma is a primary bone tumor and would not be expected to present with multiple lesions.

The most likely causative agent for the presented symptoms and findings is HSV 1 (Herpes Simplex Virus 1). HSV 1 is known to cause encephalitis, which is inflammation of the brain. The symptoms of alterations in mood, behavior, and memory followed by coma and death are consistent with the progression of HSV 1 encephalitis. The localization of the hemorrhagic necrotizing encephalitis to the temporal lobes further supports the diagnosis, as HSV 1 commonly affects this area of the brain.

The correct answer is "decreased serum C1q and C4 with absent glomerular C1q and C4." This answer suggests that the patient has Berger's Disease (IgA nephropathy). In this condition, there is deposition of IgA immune complexes in the glomeruli of the kidneys, leading to inflammation and damage. The decreased serum levels of C1q and C4 indicate activation of the classical complement pathway, which is commonly seen in immune complex-mediated diseases. The absence of C1q and C4 in the glomeruli further supports the diagnosis, as it suggests deposition of immune complexes in the kidney tissue.