Brown tumor seen in (AIIMS May 2014)
Pathology of Skeletal changes in hyperparathyroidism
1). Diffuse bone resorption: The Howship lacunae are filled with large number of osteoclasts and the Haversian canals are enlarged.
2). Brown tumours: The "tumour" is a well circumscribed dark brown area of soft consistency, situated where bone resorption has been severe.
3). Osteitis fibrosa cystica: Healing in case of hyperparathyroidism occurs by fibrous tissue replacement or sometimes the centre may liquefy and a bone cyst remains.
4). Deformities: Intervertebral disk becomes ballooned as they indent soft vertebral bodies forming the 'Cod Fish spine'.
Note: Osteopetrosis is not a feature.
The early finding is that of generalized deossification.
2). Subperiosteal resorption:
Subperiosteal erosions are most frequently identified along the middle phalanges of the index and middle fingers is a characteristic feature. (Tufting of the phalanges.)
This x-ray feature is virtually diagnostic of hyperparathyroidism.
3). Pinhead stippling:
The skull displays a diffuse osteoporosis described as pinhead stippling (pepper pot appearance)
4). Mandible x-ray = Demineralization of mandible
5). Calciphylaxis = Metastatic calcification of blood vessel (secondary to hyperphosphatemia) may lead to ischemia damage to skin & other organs.
6). Rugger Jersey spine is seen in CRF
Location of the parathyroid adenoma:
a. After one hour of administration of technetium 99m, uptake is done by both thyroid and parathyroid gland.
b. After 3 hrs uptake evidence is there only in parathyroid. So by computer subtraction adenoma is located.