MESENCHYMAL TUMORS 2

LipomaLipoma

"Knapsack” tumor: lipoma

Lipoma: encapsulated, lobular, and homogenous

Lipoma

Well defined, lobulated

Lipoma

Normal mature fat cells

Lipoma

Myxoid changes: myxolpoma

Lipoma

Angiolipoma, capillary-sized vessels some with thrombi surrounded by spindle cells

LiposarcomaLiposarcoma

Liposarcoma (skin)

Tumor compression (mesenterial liposarcoma)

Liposarcoma

Lipoma-like liposarcoma (LS): fat with fibrous band, multiple lobules, well defined.

Myxoid LS: intramuscular, gelatinous,cystic, well defined

Liposarcoma (skin)

Liposarcoma

Lipoma-like LS: fibrous band

Liposarcoma

Sclerosing LS: fibrous band and fat cells

Liposarcoma

Liposarcoma

Myxoid matrix with varying cellularity

Liposarcoma

Myxoid Liposarcoma: chicken wire vessels, myxoid matrix, mini lipoblast and spindle cells

Liposarcoma

Round cells Pleomorphic, large lipoblast

PleomorphicLymphnode: metastatic signet-ring cell Ca of the breast

Leiomyoma Leiomyoma LeiomyosarcomaLeiomyosarcoma

Smooth muscle, relaxation

Smooth muscle, contraction

Benign vs Malignant Tumors

Leiomyoma (uterus)

Leiomyoma (uterus)

Leiomyoma

Moderate cellular lesion, composed of spindle cells with an elongated nucleus with rounded ends (blunt-ended, cigar-shaped). Note the

Perinuclear vacuolization and perpendicular crossing

Leiomyoma

Leiomyosarcoma (uterus)

Leiomyosarcoma (uterus)

Leiomyosarcoma

Leiomyosarcoma

Similar cell shape and constellation with atypical cells, nuclear pleomorphism, high mitotic activity and necrosis

Leiomyosarcoma

Leiomyosarcomaskin, low grade

Leiomyosarcomapartial epitheloid, high grade

RhabdomyosarcomaRhabdomyosarcoma

Rhabdomyosarcoma

Pleomorphic type, giant cells and tumor cells with bizarre nuclei

"Rotten Meat" appearance of rhabdomyosarcoma

Rhabdomyosarcoma

Alveolar rhabdomyosarcoma with numerous spaces lined by the tumor cells

Rhabdomyosarcoma

Malignant small round cells with abundant cytoplasm

"Small Round Blue Cell Tumor" (Rhabdomyosarcoma)

Pleomorphic rhabdomyosarcoma from adult extremity

Positive desmin immunostain = skeletal muscle differentiation

Positive muscle specific actin immunostain in same case

HemangiomaHemangiomaLymphangiomaLymphangiomaAngiosarcomaAngiosarcoma

Hemangioma Pyogenic granuloma

Capillary Hemangioma

Congenital capillary hemangioma at birth (A), and at 2 years after spontaneous regression

Capillary hemangioma

Capillary hemangioma

Capillary hemangioma

Cavernous hemangioma

Cavernous hemangioma

Lymphangioma, retropancreatic and intraabdominal

Lymphangioma

hygroma

hygroma

Angiosarcoma

Angiosarcoma in post-mastectomy arm edema (Stewart-Treves)

Angiosarcoma (liver)

Angiosarcoma

Angiosarcoma of the breast: intraparenchymatous, lobulated, brown hemorrhage

Angiosarcoma

Well differentiated angiosarcoma with labyrinth of vessels, infiltrating fat

Angiosarcoma

Poorly differentiated, epitheloid, solid pattern, with irregular vessel structure

Angiosarcoma

A. Angiosarcoma of the heart (right ventricle)B. Moderately differentiated, with dense clump of irregular,

moderate anaplastic cells and distinct vascular lumenC. CD31 positive (endothelial marker)

Angiosarcoma(HE) x 75

Angiosarcoma

FNA: plump spindle/hobnail cellsdissociating, large nuclei with irregular chromatin

Benign fibrous histiocytomaBenign fibrous histiocytoma Malignant fibrous histiocytoma Malignant fibrous histiocytoma

Benign fibrous histiocytoma

AJH pada MFH

"Fish Flesh" gross appearance of sarcoma

MFH

MFH

MFH

Malignant fibrous histiocytoma revealing fascicles of plump spindle cells in a swirling (storiform) pattern, typical but not

pathognomonic of this neoplasm.

Nuclear atypia in high grade sarcoma (MFH)

MFH

MFH

MFH

Myxoid type, the same case

MFH, Myxoid type

MFH

Giant cell type