GPR: 2020 - Week 31

From MGH Learn Pathology

Clinical history

62 y/o F with shoulder stiffness and a ‘lobulated signal’ on imaging

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Synovial chondromatosis
Benign, multinodular proliferation of hyaline cartilage within articular synovium, tendon sheath or bursa Knee, hip and elbow are most common sites. Small, opalescent, cartilaginous nodules (0.1-1.0 cm) that coalesce into larger conglomerates

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Chondrosarcoma arising in association with synovial chondromatosis

Chondrosarcomatous transformation of synovial chondromatosis is extremely rare ‘Synovial chondrosarcoma’ described most often as a malignant transformation of pre-existing synovial chondromatosis Large cartilaginous tumor arising in intra-articular cavity.

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Deposition of monosodium urate crystals Classically occurs in 1st metacarpophalangeal joint Chalky yellow-white deposits of MSU form on articular surface, synovium, ligaments, tendons, bursae and periarticular soft tissue

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Tenosynovial Giant Cell Tumor

Benign soft tissue tumor of synovial origin Diffuse type or localized type Localized type predominantly in digits, well circumscribed and encapsulated Diffuse type most commonly affects large joints and forms intrarticular villonodular masses. May have extraarticular tumors Variegated tan, yellow, to red/brown cut surface

This week's Gross Pathology Roundup was presented by Kristine Marie Chaudet on MD.