Soft Tissue Tumors Flashcards
What causes this type of lesion?
Blunt trauma, usually to lower limb
(Myositis ossificans - note calcification of muscle in lower limb)
In which population would you expect to see this tumor?
Young adult female
(Desmoid tumor in abdominal wal = note skeletal muscle + spindle cell proliferation w/o necrosis)
What may have caused this tumor?
Minor trauma like thorn prick or insect bite
(Dermatofibroma - note dimpling of nodule)
Name the predominant cell type in this photomicrograph. Dx?
Lipoblast; Liposarcoma
(Irregular nuclei + lipid vesicles in cytoplasm)
How would this lesion appear on histology?
Fibroblast in tissue culture appearance/spindle cells in loose matrix
(Nodular fascitis - note well circumscribed mass on forearm of young adult)
How would this tumor look on histology?
Abnormal cells which recapitulate skeletal muscle +/- cross striations
(Rhabdomyosarcoma - notice involvement of the orbit in kid)
This tumor is most commonly seen in:
Reproductive age women (25-40%)
(Leiomyoma - well-circumscribed white tumor in uterus)
This is an example of the most common type of:
Superficial fibromatosis
(Dupuytren’s contracture - note the flexion of ring and pinky fingers with sparing of the thumb and index finger)
Where would this tumor most likely present?
Lower limb
(Woven bone in granulation tissue = myositis ossificans)
How would this present clinically?
Middle-aged to older adult with progressively growing soft, nontender mass
(Liposarcoma - notice the lipoblasts with bizarre nuclei and lipid vesicles in their cytoplasm)
Two ways this tumor can present?
In tibia or femur in male in 4th decade of life = painful
In thigh or posterior knee in 35-55 year old = painless
(Fibrosarcoma - not the herringbone pattern of fibroblasts)
Complication of this type of tumor?
Hemorrhagic necrosis if it outgrows its blood supply
(Leiomyosarcoma - cigar-shaped cells resembling smooth muscle with mitotic figures)
From where does this tumor arise? What happens with treatment?
Dermis
High recurrence rate
(Dermatofibrosarcoma protruberans - notice umbilicated nodule; locally aggressive into subQ tissue)
What causes this lesion?
Mesenchymal reaction to injury
(Nodular fascitis - note spindle cells in loose stroma)
What would you expect to see on histology of this lesion?
Inclusion-like cytoplasmic condensation of actin
(Infantile digital fibromatosis)
What would this tumor look like grossly?
Fish flesh - fleshy, white tumor
(Rhabdomyosarcoma - note skeletal muscle resemblance)
What would the most common soft tissue sarcoma look like on histology?
Storiform pattern with spindle-shaped and round cells +/- giant cells
(Malignant fibrous histiocytoma - fibroblastic and histiocytic origin)
This tumor is comprised of:
Malignant fibroblasts of mesenchymal origin
(Fibrosarcoma - note the herringbone pattern)
How can this lesion be differentiated from a malignancy?
Malignancy won’t have any maturation pattern, unlike this tumor which shows mature bone at the periphery
(Myositis ossificans - woven bone in granulation tissue with mature bone at periphery and immature bone in center)
Cell type of this tumor?
Dermal histiocytes
(Dermatofibroma - note dark nodule on arm)
Where is the most likely site to which this tumor would metastasize?
Lung
(Malignant fibrous histiocytoma - notice characteristic giant cells and storiform pattern)
Other common sites for this type of tumor?
Orbit
Arms/legs
Repro/urinary organs
Nasopharyngeal
(Rhabdomyosarcoma - parameningeal)
Where would you most likely see this tumor?
Uterus
(Leiomyoma - cigar-shaped cells resembling smooth muscle; no mitotic figures)
