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Musculoskeletal Pathology - Coggle Diagram
Musculoskeletal Pathology
Tumors of epidermis
Benign
Viral squamous cell papilloma of skin
Definition
Caused by low risk HPV viruses
Called Skin warts or
Verrucae
Types
Verrucae Vulgaris
(Common warts
Most common
Anywhere on skin but most commonly on fingers (natret el 7omar)
Keratotic exophytic growths
Verrucae Plana
(Flat wart)
Commonly on the face and back of hands (by kissing)
Verrucae Plantaris
(Plantar warts)
Deeper
occurring in sole of children
Condyloma acuminatum
(Genital warts)
Large and fleshy
appear in genitalia and uterine cervix
Malignant
Squamous cell carcinoma
Site
Skin
Squamous mucous membranes
Other mucous membranes on top of metaplasia or leukoplakia
Predisposing Factors
Prolonged exposure to sunlight
Metaplasia and leukoplakia
Exposure to Carcinogens such as arsenic and tar
Macro
Fungating polypoid pattern
Ulcerative pattern
Irregular margins
Raised everted edges
Indurated base
rough necrotic floor
Infiltrative pattern
Micro
Cell nests
Dermis or submucousa is infiltrated by malignant epithelial cells in which well differentiatied neoplasms form cell nests
Replicate normal organization of epidermis : :
Spread
Behavior
Basal cell carcinoma
Macro
Micro
Behavior
Spread
Site
Predisposing factors
Melanocytic Proliferations
Melanoma
Def
Malignant melanocytic tumor
Less common but more deadly than squamous or basal cell carcinoma
Etiology
related to sun exposure
Sites
Skin
Meninges
Esophagus
Eye
Oral and anogenital mucosal surfaces
Macro
Shape
Irregular border
Marked variation in pigmentation
Shades of black, brown , red, and dark blue
Size
Larger than nevi
Tumor development
Radial Phase
growth horizontally in epidermis (insitu) for a prolonged period
No angiogenesis (In epidermis, not under basement membrane) -----> incapable of metastases
Appears clinically as flat lesions
Growth phase
Growth into the deeper layer of the dermis
Clinically as a nodule
coorelates with emergence of a clone cells with metastatic potentials
Micro
In insitu (radial) phase
poorly formed nests around dermoepidermal junction
Single cells and small groups scattered in upper epidermis
in vertical phase
Form dermal nodules
Individual cells
Epithelioid appearance
Large
Large nuclei
Cherry red eosinophilic nucleolous
Sarcomatous appearance
Spindle shaped
Base shows a band of lymphocytic infiltrate
Why?
reflect a host immune response to tumor antigens
Behavior
Aggressive with frequent blood and LN metastases
Probability of metastases is detected by measuirng depth of invasion
Melanocytic Nevus
Soft Tissue Tumours
Intro
Include mesenchymal tumors other than bone and cartilage
Benign are more common than malignant
Rise from pluripotent cells not mature mesenchymal cells
Tumors of adipose tissue
Lipoma
Def
Most common soft tissue tumor
Clinical picture
Mobile, soft, slowly growing painless mass
Mostly from SC fat but rises from intermuscular septae, breast mediastinum, omentum, and GIT
Micro
With fibrous septa dividing tumor into lobules of mature fat cells
Fibrous capsule
Macro
Soft, yellow, encapsulated mass
lobulated greasy cut surface
Liposarcoma
arising from deep tissue esp. retroperitoneum as well-circumscribed masses
vary in degree of differentiation and various histologic subtypes with variable prognosis --> lipoblast
Rare, occurring in 5th to 6th decade
Tumors and tumor-like lesions of fibrous tissue
Fibroma
Morphology
Capsulated firm globular mass
Whorled grey cut section
Secondary changes as hyalinosis and calcification (necrosis since no blood supply
Def
uncommon benign tumor of fibrous tissue
Site
Also in ovary and GIT
Dermis
Fibromatosis
Definition
Group of fibroblastic proliferation
Cytologically benign
with infiltrative fashion
Can recur after surgical excision but no metastasis
Types
Superficial
Palmar fibromatosis
in palmar fascia
causes contraction and deformity of ring and little finger
Plantar fibromatosis
In sole of the feet
no clinical effect
Penile fibromatosis
called Peyronie (البيروني) disease
causes penis to become curved---> no ejaculation
Deep
Abdominal desmoid tumor
arises from rectus abdominus
occurs in post-partum women and scars of abdominal surgery
Extra-abdominal desmoid
arises from shoulder or pelvic girdle
retroperitoneal fibromatosis
usually leads to renal failure due to pressure on ureter
Fibrosarcoma
Definition
Malignant tumor composed of fibroblasts
Clinical picture
Occurs in adults
deep tissue of the thigh and retroperitoneal areas
grow slowly
Recur locally
metastasize by blood
Macro
un-encapsulated
Fleshy masses
may be circumscribed
Micro
high-grade
are pleomorphic with frequent mitosis and necrosis
Spindle cells arranged in fascicles with
Herring bone arrangement
in
well differentiated tumors
Fibrohystocytic tumours
Def
Mixture of fibroblasts (myofibroblasts) and phagocytic cells (may be lipid-laden) resembling histiocytes
Types
Benign fibrous histocytosis
Occurs in skin
Also called dermatofibroma
Malignant fibrous histocytosis
Pleomorphic tumors
Arranged in storiform or cartwheel patter with many giant cells
Arise in deep muscles and is extremely aggressive (diagnosed after death)
Skeletal muscle tumors
Rhabdomyosarcoma
Incidence
most common soft tissue tumor in children under age of 20
Site
Head and neck (embryonic precursors rise from there)
and genitourinary tract
Types
Embryonic
Arises in hollow organs like bladder or uterus
arises as soft, gelatinous, grap-like masses (Sarcoma botryoides)
Alveolar
Pleomorphic
Micro
Diagnosed by rhabdomyoblast (primitive skeletal muscle cell)
Prognosis
Aggressive neoplasm
Treated by surgery, chemotherapy, and radiation
Occurs in little female babies and they usually die
Rhabdomyoma
Very rare
occurs in heart
Smooth Muscle tumors
Leiomyomas
Definition
Benign soft muscle tumors
arises from smooth muscles anywhere in the body
Site
Uterus and GIT
Leiomyosarcomas
Definition
malignant soft muscle tumor
Site
Uterus
Stomach
Macro
Large, bulky fleshy mass
With areas of hge and necrosis
Vascular tumors
Glomus tumor
Benign tumor arising from glomus bodies (involved in heat regulation)
tender mass in the distal portion of the fingers
Hemangioendothelium
vascular tumors of intermediate behavior
Lymphangioma
Often congential tumor of lymphatics
made of small channels or large cystic spaces
separated by CT stroma containing lymphocytes
Spaces do not contain blood
Tumor margins are indistinct and non-encapsulated
they form a large cystic mass in the neck or axilla called cystic hygroma
Kaposi Sarcoma
Caused by HHV-8
types
Classic type
affects elderly males
in the form of red patches, plaques, or nodules in the lower extremity
Common in jews and in the mediterranean area
African Type
affects a younger age
More LN involvement
AIDS-related or organ transplant recipients
More aggressive
Affects LNs, mucosa, and viscera
Microscopic
Proliferated small irregular vessels
separated by plump spindle cells
and extravasated blood cells
Hemangioma
Definition
very common
composed of blood-filled spaces
common in infants and children
Mostly present since birth
Types
Capillary hemangioma (strawberry birthmark)
Most common hemangioma
occurs in
Skin (especially arounf the eye)
Subcutaneous tissues
mucous membranes of the oral cavities and lips
liver spleen and kidney
Micro
Capillary sized vessels
Lined with flat endothelium
surrounded by scan stroma
Pyogenic granuloma
Capillary hemangiomas manifesting as growing red pedunculated lesions
On the skin, gingiva, or oral mucousa
Commonly ulcerate
Cavernous hemangioma
Frequently involve deep structures
formed of large dilated cystic spaces containing blood
Sharply, defined non-encapsulated mass
Angiosarcoma
definition
Malignant tumor affecting older adults
Occur anywhere but mostly skin, soft tissue, breast and liver
Angiosarcomas of the liver
related to
arsenical pestisides
polyvinyl chloride
thorotrast (used in radioimaging)
Angiosarcoma arising in the setting of lymphedema
occurs in upper limb after radical mastectomy
Vascular Ectasia
Also called telangiectasia, birthmark, nevus flammeus
Permanent dilation of a small vessels
Tumors of uncertain etiologies
Occur in young adults --> 20-40 years
Deep soft tissues NEAR big joints (mainly knee)
Biphasic tumor
involving both spindle cells and epithelial-like cells
Aggressive tumors with frequent metastases to bone, lungs, and LNs