Soft Tissue Tumors Flashcards
What is the cause of most soft tissue tumors?
Majority of tumors occur _________
Unknown (Documented association following rad therapy, and some rare burns( chemical and thermal) and trauma
Sporadically
Where do soft tissue tumors arise?
Any location, but 40% of sarcomas occur in lower extremity, esp. thigh
What is the relationship between soft tissue tumors and ages?
Incidence of sarcomas increases with age (15% arise in children)
What are the primary diagnostic features used? What ancillary techniques are used to aid in diagnosis?
Primary
- Cell morphology
- Architectural arrangement
Ancillary techniques:
- Immunohistochemistry
- Electron microscopy
- Cytogenetics
- Molecular genetics
What are prognostic factors for soft tissue tumors?
- Grading (I-III): Degree of differentiation, avg. number of mitoses, extent of necrosis
- Size (> or <5 cm)
- Depth (above or under fascia)
- Stage (I-IV) of tumor
- Superficial locations have better prognosis than deep lesions
What is treatment for soft tissue tumors?
Wide surgical excision (frequently limb-sparing) usually
Irradiation and systemic therapy reserved for large high-grade tumors
What is the most common soft tissue tumor of adulthood?
Lipoma
How do lipomas usually present and how are they treated?
Most are solitary lesions, mobile slowly enlarging, painless (except angiolipoma) masses
Complete excision usually is curative
What is the morphology of lipoma?
Suclassified according to particular morphological feature (angiolipoma, spindle cell, etc.) Conventional lipomas (most common) are soft, yellow, well-encapsulated masses Consist of mature white fat cells with no pleomorphism
Genetic variant for lipomas
12q14-q15
What is one of the most common sarcomas of adulthood (40-60s)?
Liposarcoma
Where do liposarcomas arise and what is their morphology?
Deep soft tissues of proximal extremities and retroperitoneum, may develop into large tumors
Well-differentiated, myxoid/round cell, and pleomorphic histological variants
What is the behavior of liposarcoma?
WD-LPS is relatively indolent
Myxoid/round cell type is intermediate
Pleomorphic variant usually agressive and may metastasize
All types recur locally unless adequately excised
What is the genetics of liposarcoma?
WD-LPS: Supernumerary ring chromosomes (amplification of 12q14-15, containing MDM2)
Myxoid/round LPS: t(12;16)(q13;p11)
What are pseudosarcomatous proliferations?
Reactive non-neoplastic lesions that develop in response to some form of local trauma or are idiopathic
Develop suddenly and grow rapidly
Hypercellularity, mitotic activity, and primitive appearance mimic sarcoma
What are the two types of pseudosarcomatous proliferations and their qualities?
Nodular fasciitis: deep dermis, subcutis or muscle
Several centimeters
Myositis Ossificans: Proximal extremities, young adults, trauma in >50% of cases
Presence of metaplastic bone; eventually the entire lesion ossifies and the inertrabecular spaces become filled with bone marrow
Must be distinguished from extraskeletal osteosarcoma
Where do superficial fibromatoses arise?
Palmar (Dupuytren contracture)
Plantar
Penile (Peyronie disease)
What is the prognosis of superficial fibromatoses?
May stabilize and resolve spontaneously, some recur
Deep-Seated Fibromatosis (Desmoid Tumors)
Behavior?
Age?
Associated disease risk?
Gene association?
Behavior lies between benign fibrous tumors and low-grade fibrosarcomas; frequently recur after incomplete excision
Most frequent in the teens to 30s
Some associated with Gardner syndrome
Mutations in the APC or Beta-catenin genes
What is fibrosarcoma?
What age does it target?
Where does it target?
Rates of recurrence and metastasize?
- Malignant tumors composed of fibroblasts
- Mostly adults
- Deep tissues of the thigh, knee, and retroperitoneum
- Aggressive tumors, recur in >50% of cases, metastasize in >25%
What is the most common neoplasm in women?
Uterine leiomyomas
Where do leiomyomas arise?
What is the size?
What is the prognosis?
- Uterine, skin, deep soft tissues
- <1-2 cm
- Solitary: Easily cured, Multiple: May be difficult to remove
What percentage of soft-tissue sarcomas are leiomyosarcoma?
Who is the most susceptible?
Where do they proliferate?
Prognosis?
- 10-20% of soft-tiisue sarcomas
- Adults, F>M
- Skin and deep soft tissues of the extremities and retroperitoneum
- Superficial leiomyosarcomas usually small and have good prognosis; retoperitoneum sarcomas are large cannot be entirely excised
What is the age of incidence for rhabdomyosarcoma?
Where does rhabdomyosarcoma arise?
What are the subtypes?
- Most common soft tissue sarcoma of childhood and adolescence (Before age 20)
- Head, neck, GU tract, sites where little if any normal skeletal muscle
- Embryonal, alveolar, pleomorphic
What are the rates of embryonal RMS?
Age of RMS
Location of RMS
Variants of RMS
- 49% of RMS
- <10 years of age
- Head/neck (orbit and parameninges), GU tract, deep soft tissues of the extremities, pelvis and retroperitoneum)
- Variants: Sarcoma botryoides, spindle cell, anaplastic
Alveolar RMS
- Age
- Location
- Genetic variant
- 10 and 25 years of age
- Deep soft tissues of the extremities: head and neck, perineum, pelvis, retroperitoneum
- t(2;13)/PAX3-FKHR or t(1;13)/PAX7-FKHR in most (80-85%) of alveolar RMS
Synovial sarcoma
- Rate
- Who is at risk
- Where do they develop
- Genetic variant
- Histology
- Treatment
- Prognosis
- 5-10% of all soft tissue sarcomas
- Young adults, more commonly in males
- Over 80% in the deep soft tissue of extremities, especially around the knee, metastatic sites are lung, bone, and regional lymph nodes
- Characteristic t(X;18) (p11;q11)
- Histologically biphasic or monophasic
- Aggressively with limb-sparing surgery and chemotherapy
- 5-year surival rates from 25% to 62% and only 10-30% of patients live longer than 10 years
