Depression has been linked with alterations in taste sensation, including decreased sensitivity to sweetness. This may contribute in some part to the high consumption of sweet foods in certain individuals experiencing a depressive episode. None of the other conditions listed have been correlated with alterations in taste receptor function. 

The correct answer is "Anorexia nervosa." This is the correct answer because in this patient, who is a young female, which is the most commonly encountered demographic for eating disorders, she notes that she has been drastically restricting her intake of food, that she has body dysmorphic thoughts (e.g. thinking that she is "too fat" despite that her BMI is 14), and we learn that her BMI is 14. A diagnosis of anorexia can be made if a patient is restricting their eating or drinking intentionally, and/or is participating in purge behavior, and has a BMI less than 17.5, as in this patient. 

Should this patient have presented in an identical manner, but her BMI been greater than 17.5, by definition, the correct answer would be bulimia nervosa. Given her BMI though, bulimia nervosa is not correct. There is no evidence of binge-eating behavior in this patient either, making that answer incorrect.

While generalized anxiety disorder and/or major depressive disorder are often co-morbid in patients with eating disorders, there is not enough evidence in the example to suggest either diagnosis for this patient. 

Patellofemoral syndrome presents as pain in the front of the knee, sometimes caused by wearing down, roughening, or softening of the cartilage under the kneecap. Osgood-Schlatter disease is a syndrome of irritation of the patellar ligament at the tibial tuberosity, characterized by painful lumps just below the knee, most often seen in young adolescents. Legg-Calvé-Perthes syndrome is due to disruption of blood flow to the femoral head, leading to avascular necrosis. Congenital scoliosis is a spinal deformity characterized by the curving of the spine at an angle greater than 10 degrees on radiography.

Osgood-Schlatter syndrome of irritation of the patellar ligament at the tibial tuberosity, characterized by painful lumps just below the knee, most often seen in young adolescents. Risk factors may include overzealous exercise but it's ultimately thought to be caused by adolescent bone growth. Osteosarcoma, the most common bone cancer in adolescent populations, can present with pain and a lump or frank swelling. This is caused by actual tumor growth, not by any ligamentous issue. Osteosarcoma does present frequently in the knee, and must be ruled out before a diagnosis of Osgood-Schlatter disease is made. Slipped capital femoral epiphysis causes pain and reduced movement in the hip, rather than the knee. Osteomalacia is a general softening of the bones caused by a deficiency in vitamin D.

Psoriatic arthritis will often show a pencil-in-cup deformity on x-ray. Osteoarthritis will show joint space narrowing, sclerosis, and osteophytes. Rheumatoid arthritis and juvenile rheumatoid arthritis will both show soft tissue swelling, joint space narrowing, and may show marginal erosions. 

Swan neck deformity is often seen in patients with rheumatoid arthritis. This is a state in which the distal interphalangeal joint (DIP) becomes hyperflexed (bends toward the palm) while the proximal interphalangeal joint (PIP) is hyperextended (bending away from the palm). Shepherd's crook deformity is seen in Paget's disease of the bone, pencil-in-cup deformity is seen in psoriatic arthritis, and Heberden nodes are frequently seen in the distal phalanges of patients with osteoarthritis.

Duchenne's is the most common and most severe form of muscular dystrophy, accounting for a full 50% of cases of muscular dystrophy in the US. The next most common type is Becker's, followed by myotonic muscular dystrophy and Emery-Dreifuss.

Lambert-Eaton syndrome is a condition of progressive muscle weakness caused by an auto antibodies to presynaptic calcium channels in the neuromuscular junction. This does not allow calcium to enter the presynaptic cell, which is required for neurotransmitter release into the synaptic cleft. Without the release of neurotransmitter, there will be no muscular response. Myasthenia gravis is an autoimmune condition in which antibodies are formed against acetylcholine receptors, and muscular weakness in multiple sclerosis is caused by destruction of myelin in the CNS due to antibodies against oligodendrocytes. Dermatomyositis is an inflammatory connective tissue condition that may be associated with a post-viral autoimmune reaction or triggered by a paraneoplastic syndrome. 

Histological findings of dermatomyositis will generally reveal mixed B cell and T cell perivascular inflammatory infiltrate and perifascicular muscle fiber atrophy.

Fibrosed muscle fibers and fatty infiltrates are typical of Duchenne's muscular dystrophy, while granulomas in muscle are rare but may be seen in sarcoidosis and other conditions of granulomatous myositis.

A rhabdomyoma is a benign tumors of striated muscle. 90% of adult rhabdomyomas present as round masses in the neck.