Schwannomas are rare tumors. Since these tumors are derived from nerve sheaths and not from axons there is controversy regarding histogenesis and terminology. There is histological and histo-chemical evidence to consider that cells involved in the development of these tumors are schwannian cells and should be designated as schwannomas or neurilemomas, either benign or malignant. They are asymptomatic unless the lesion is large. The exact cause is not known.

Fibro-lipomatous hamartomas are non-malignant tumors that are commonly seen in infants and rarely affect young adults and children.[1] Neural fibro-lipoma, lipo-fibromatous hamartoma, peri-neural lipoma and intra-neural lipoma are the other terms used for fibrolipomatous hamartoma. Among all, the median nerve is by far the most commonly affected(80% of cases) and less commonly the ulnar and radial nerves, and brachial plexus. [2] Although median nerve is the commonly affected nerve, lesions are also found in the radial, sciatic, plantar and ulnar nerves. Further,the median nerve is most commonly involved at the level of hand and wrist.[3]

Fibrous dysplasia is an ailment , that can include , one or a few bones and is portrayed by bone deformations, pain and fractures, arising due to bone weakening. A few patients can also present with endocrine dysfunction ( precocious puberty) and cutaneous cafe '- au - lait spots.[1] Determination depends on X-ray assessment. Anticipation is to be surveyed with X-rays and markers of bone remodelling. A few newer comprehensions , of the patho - physiology have been made in the past I0 years. It is presently perceived that fibrous dysplasia is brought about , by a physical initiating transformation of the Gs alpha subunits , of the protein G, bringing about an expanded cAMP fixation and in this way, brings about anomalies of osteoblasts separation, and then subsequently these osteoblasts, creates abnormal bone. There is also an expansion in interleukin-6-initiated osteoclastic bone resorption, which forms the basis of reasoning, for treating these patients with bisphosphonates. In the previous 10 years, the bisphosphonate pamidronate has been utilized by imbuement for fibrous dysplasia (two courses for each year), with great outcomes regarding pain and, in about half of patients, the topping off of osteolytic sores.[2]

Geode or subchondral bone cyst is a lytic lesion in the peri-articular area and this condition is seen as a cyst or cyst erosion in a bone end. Basically, a cyst is lined by epithelium but subchondral bone cyst is not lined by epithelium. Subchondral bone cyst are common in various articular diseases.