Ch. 21 - Tumors of fat, muscle, cartilage, and bone Flashcards
Lipoma, intramuscular lipoma
Well-cirumscribed mature lipocytes within a thin capsule.
Intramuscular: Usually of the forehead, displacing muscle fibers
Angiolipoma
Clinically tender lipoma with capillary proliferation. Often with erythrocytes and scattered fibrin microthrombi.
Spindle cell lipoma
Firm and fixed lipoma with bland CD34+ spindle cells and variable collagen.
Fibrolipoma
Well-circumscribed tumor of mature lipocytes containing large bundles of mature collagen
Pleomorphic lipoma
Firm tumor of lipocytes containing multinucleate floret giant cells. May have myxoid areas and ropey collagen bundles.
Angiomyolipoma
Well-circumscribed tumor with mature fat and smooth muscle radiating in a pinwheel fashion from the walls of muscular vessels.
Hibernoma
Grossly brown tumor with multivacuolated mulberry cells.
Nevus lipomatosis superficialis of Hoffmann and Zurhelle
Replacement of the dermis with mature fat.
Leiomyoma
Long, thin cigar-shaped nuclei with blunt ends. Often with paranuclear glycogen vacuole.
Piloleiomyoma
Circumscribed but non-encapsulated nodule of interlaced smooth muscle fibers without mitoses.
Angioleiomyoma
Tender subcutaneous nodule with several layers of smooth muscle merging with slit-like vascular spaces.
Leiomyosarcoma
Highly cellular, mitotically active and atypical lesion with fusiform cells.
Osteoma cutis
Dermal or subcutaneous bone with normal bone features such as haversian canals, osteocytes in lacunae, and osteoclasts.
Relapsing polychondritis
Cartilage with surrounding perichondral neutrophils. DIF with continuous IgG/A/M and C3 in the perichondrium.
Accessory tragus (cartilaginous rest)
Fibrovascular polyp containing numerous vellus follicles and a core of adipose tissue & cartilage.
Chondroma
Circumscribed mass of mature hyaline cartilage with chondrocytes in lacunae. Can calcify
Chordoma
(IHC?)
Axial lesion with lobules of physaliphorous cells in a chondroid stroma.
S100+, vimentin+, keratin+
Pseudocyst of the auricle
Usually reactive intracartilaginous space without a true lining or inflammatory reaction.
Supernumerary nipple (polythelia)
Subtle epidermal thickening with underlying pilosebaceous structures, smooth muscle bundles, adn mammary duct.
Mobile encapsulated lipoma (encapsulated fat necrosis, nodular-cystic fat necrosis)
Lobules of necrotic fat surrounded by fibrous capsule
Smooth muscle hamartoma, becker’s nevus
Numerous haphazard bundles of smooth muscle in the dermis.
Becker’s: Hyperpigmented and hypertrichotic
Subungual exostosis
Bony stalk with fibrocartilaginous cap under the nail plate.
Focal dermal hypoplasia (Goltz syndrome)
(cause?)
Markedly hypoplastic dermis with adipocytes approaching the papillary dermis
X-linked dominant mutation in PORCN
Lipoma
