Lecture 84 - Parathyroid & Non Neoplastic Bone Pathology Flashcards
what are the different cell types in the parathroid
how do they stain
which secrete PTH
Chief cells – blue/clear – secrete PTH
Oxyphil cells – pinker; lots of cytoplasm; lots of mitrochondira
fat in between (adults > kids)
three types of abnormal parathyroid growth
Parathyroid Adenoma -
Parathyroid Hyperplasia
Parathyroid Carcinoma
Parthyroid hyperplasia is associiated with _____
Multiple Endocrine Neoplasm 1 and 2
what is sufficienct to make the the diagnosis of parathyroid carcinoma
what other clinical clues might be present
Carcioma = metastatic disease
High serum Ca or PTH
Palpable mass
Vocal cord paralysis
manifestations of hyperPTH in other organs include
Hypercalcemia
Metastatic calcification
Urinary Stones Nephrocalcinosis
Bone disease
Normal bone histology –
what are the non cellular components?
what are the cellular components and function of each?
Non Cellular –
Organic Matrix – Mostly Type 1 collagen, Provides Structure
Calcium hydroxyapatite – Provides hardness
Cells –
Osteoblasts – build bone
Osteoclasts – resorb bone; chew up existing bone make room for new bone (multinucleated cells)
Osteocytes – identify areas of weakness to recruit osteoblasts to remodel the bone (Mechanotransduction)
what are the two architectural patterns of bone? which one is pathologic if seen in adults
Lamellar bone –
Slow built strong bone designed to withstand tension
Look for parallel lines
Woven Bone – PATHOLOGIC IN ADULTS
Quick and dirty bone
Two zones of the bone are the ______ & ______
what is the relative location of each and functional significnace
Bone Cortex – outer rim of bones; made of matrix; gives strength
Bone Medulla -- Trabecular bone with intervening fat or hematopoietic precursors; provides lightness of bones
two forms of bone formation
Enchondral Ossification -
Intramembranous ossification (bones of the skull)
what is the most common growth plate d/o
Achondroplasia –
Achondroplasia –
mutation to ______
AD or AR?
AD Mutation in FGFR3, inhibits cartilage formation
what is the fatal form of a mutation to FGFR3?
Thanatophoric
Osteogenesis imperfecta —
mutation to _____
clinical features:
aka brittle bone disease
Abn of type 1 collagen
fractures, blue sclera (thin sclera), hearing impairment, poorly formed teeth
Osteopetrosis
genetic defect to____
describe the pathophysiology
how can this be treated?
what is the classic radiology finding?
Findings on histo?
osteoclasts
Never get remodelling bone; remains in the more fragile woven bone states
Tx – Bone marrow transplant
Erlenmeyer Flask deformity
Only woven bone
No lamellar bone
Medulla filled with unresorbed spongiosa
Paget Disease of the Bone:
what is it?
what cells are more active?
Localized disorder of bone remodeling caused by increased activity of osteoblastic and osteoclastic activity
what are the three phases of Paget disease of the bone?
Lytic phase – lots of osteoclasts
Mixed Phase– osteoclasts + osteoblasts
Sclerotic phase – abnormally remodelled bone; no osteoclasts or blasts. Very disorganized “mosaic pattern” of bone with mixed lamellar and woven
Vit D deficiceny of bone:
Adults is called _____
Chidlren is called _____
Adults: Osteomalacia
Children: Rickets
three forms of bone disease due to HyperPTH
Generalized bone resorption –
Brown Tumor:
Osteitis Cystic Fibrosa
Generalized bone resorption –
what is seen clinically?
What is seen on xray?
what is seen histologically?
Generalized osteoporosis
Radiology: radio-lucency of subcortical bones
Pathology: Dissecting osteoitis – “rail road tracks”
Brown Tumor:
what is it?
Aggregates of osteoclasts and reactive fibro vascular tissue (secondary to microfracture and hemorrhage) Hemosiderin macrophages
Histo: look like giant cell rich tumors and giant cell granulomas
Osteitis Cystic Fibrosa –
what is seen on xray?
Cyst formation = brown tumor burn out
