A 39 year old patient comes to see you with a soft, mobile and painless bump on her upper arm. What do you expect to see under histological examination of the bump? What epidemiological factor leads you to this expectation?
A well-encapsulated mass of mature adipocytes. You would expect to see this because lipomas are the most common soft-tissue tumors in adults.
What would you expect the metastatic potential to be in this tumor section?
This is myxoid liposarcoma. Note abundant ground substance with scattered adult fat cells and lipoblasts. This type of tumor is intermediate in it metastatic behavior compared to its pleopmorphic variant.
A patient comes to see you two weeks after a car accident complaining of a solitary, rapidly growing, painful mass on the dorsum of his forearm. What is your diagnosis?
Nodular fasciitis. These are tumors that suddenly grow, sometimes after trauma. Note the randomly oriented spindle cells, extravasated RBCs, mitotic activity and myxoid stroma.
A 15 year old track athlete comes to see you with a painful, swollen calf. You prescribe RICE and send him home. 3 weeks later he comes back and the calf has a solid mass in it that is no longer painful. You get this X-ray back from the lab. How did this tumor change over the last three weeks?
This patient has myositis ossificans. It usually begins after an episode of trauma that stimulates fibroblast activity that promotes nodular fasciitis. The fibroblasts become surrounded by osteoblasts, which deposit woven bone and the entire lesion ossifies.
A patient comes to see you complaining of progressive flexion contracture of his 4th and 5th fingers. Physical examination shows puckering and dimpling of the overlying skin on his palms. What cells are causing this condition and where else in his body could this be happening?
This patient has Superficial Palmar Fibromatosis. It is caused by secretion of dense collagen by fibroblasts that thickens the palmar fascia. This condition is also seen on the plantar and penile regions.
A 27 year old female comes to see you post partum complaining of deep abdominal pain. Upon palpation of her abdomen you note a mass in the deep muscle of her abdomen. Her tissue biopsy is shown below. Is excision of this mass an effective treatment?
This patient has a deep-seated fibromatosis. Note the broad, sweeping fascicles infiltrating the muscle tissue. These tumors usually come back after excision.
Does this look like an aggressive tumor to you?
Yes, this is a fibrosarcoma. Note spindle cells arranged in a herringbone pattern. These metastasize in more than 25% of cases and recur in 50% of cases.
Does this rhabdomyosarcoma have the best prognosis of tumors of its class?
No. This is an alveolar rhabdomyosarcoma.This type along with anaplastic embryonal and pleomorphic rhabdomyosarcomas are most fatal. The best prognosis is in the botryoid subtype.
What is the most common neoplasm in women?
Uterine leiomyomas develop in 77% of women
A 45 year old female presents with a painless, firm mass in the skin of her thigh. Histological analysis shows spindle cells with cigar-shaped nuclei in interweaving fascicles. Immunoassay shows the mass stains with antibody to smooth muscle actin and desmin. What is your diagnosis?
A 30 year old male comes to see you complaining of a deep-seated mass next to his knee. The biopsy of the mass is shown below. Calcified concretions were detected radiographically and immunohistochemical staining yielded positive for keratin. What is your diagnosis?
Synovial sarcoma. This is a biphasic tumor with epithelioid and spindle cells. Note epithelial cells forming gland-like structures.