Soft Tissue Pathology- Sarcomas

sarcomas

-malignant neoplasm of soft tissue or bone arising in fibrous, fatty, muscular, vascular, or neural tissue

-usually first manifested as a painless swelling

-<1% of the cancers in oral cavity

cell of origin → type of sarcoma

fibrosarcoma

-malignant tumor of fibroblasts

-location: anywhere in oral cavity

-age: young adults and children

-clinical features: slow-growing mass that reaches considerable size before producing pain

-histology: fascicles of spindle-shaped cells forming a “herring-bone” pattern (nuclei forming short, angular intersections), variable mitoses

-treatment and prognosis: surgical excision with a wide margin; 50% recurrence, 40-70% 5yr survival

liposarcoma

-malignant tumor of adipose tissue

-currently considered the most common soft tissue sarcoma in adults accounting for 20% of all soft tissue malignancies in adults

-head and neck cases are rare

-location: tongue and cheek

-age: 40-60yo

-clinical features: soft, slow-growing, ill-defined mass that may appear normal in color or yellow

-pain and tenderness may be present in advanced stage

-histology: vacuolated lipoblasts with pleomorphic nuclei ± less differentiated rounded cells

-treatment and prognosis: radical surgical excision, better prognosis for oral tumors due to smaller size and predominance of well-differentiated subtypes

-15-20% recurrence, rare metastasis and death

malignant peripheral nerve sheath tumor (MPNST)

-malignant tumor of the connective tissue surrounding nerves

-50% of MPNST cases occur in patients with NF Type I

-location: mandible, lips, buccal mucosa

-age: young adults, one decade younger for NF patients

-clinical features: enlarging mass that sometimes exhibits rapid growth, associated pain or a nerve deficit is common

-histology: fascicles of spindle-shaped cells with wavy or comma-shaped nuclei

-treatment and prognosis: radical surgical excision and adjuvant radiation and chemotherapy, 16% 5yr survival for NF patients, 53% 5yr survival rate for others

olfactory neuroblastoma

-malignant tumor of nasals neuroectodermal cells, similar to neuroblastomas seen elsewhere in body

-location: nasal cavity close to the cribriform plate

-age: adults, wide age range

-clinical features: nasal obstruction, anosmia, epistaxis, pain

-histology: small round to ovoid basophilic cells arranged in sheets and lobules, rosettes and pseudorosettes

-treatment and prognosis: surgical excision with adjuvant radiation therapy, chemotherapy for advanced cases, 50-90% 5yr survival depending on the size/stage of the lesion, death due to local recurrence, 20-40% metastasis

angiosarcoma

-malignant tumor of endothelium of blood or lymphatic vessels

-location: scalp, forehead, (oral is rare tongue and mandible)

-age: elderly

-clinical features: early lesions resemble a simple bruise, continues to enlarge and becomes elevated, nodular, or ulcerated, tend to be multifocal

-histology: infiltrative proliferation of blood vessels lined by atypical endothelium forming anastomosing network

-treatment and prognosis: radical surgical excision or radiation therapy or both, 21% 10yr survival for those in face and scalp, oral lesions with better prognosis

leiomyosarcoma

-malignant tumor of smooth muscle

-location: half of H&N cases occur in the jawbones

-age: middle age and older

-clinical features: enlarging mass that may or may not be painful

-histology: fascicles of spindle-shaped cells with abundant eosinophilic cytoplasm and blunt-ended, cigar-shaped nuclei

-treatment and prognosis: surgical excision + adjuvant radiation or chemotherapy, 62% 5yr survival

rhabdomyosarcoma

-malignant tumor of skeletal muscles, most common soft tissue sarcoma in children

-60% of soft tissue sarcomas in childhood, only 2-5% of soft tissue sarcomas in adults

-most frequent site is the H&N (35% of all cases)

-subtypes: embryonal, alveolar, undifferentiated, anaplastic- most oral lesions are embryonal and alveolar types

-location: in the head and neck- the face and orbit, followed by the nasal cavity; palate = most frequent intraoral site

-age: young children - young adults

-clinical features: painless, infiltrative mass that grows rapidly

-histology: embryonal- sheets of small round cells with hyperchromatic nuclei, alveolar- aggregates of round to oval cells separated by fibrous septa with a central loss of cohesiveness resembling alveoli

-treatment and prognosis: surgical excision + multiagent chemotherapy ± post-op radiation therapy, 50% recurrence, 66-95% (embryonal) and 53% (alveolar) 5yr survival

malignant fibrous histiocytoma

-sarcoma with both fibroblastic and histiocytic features

-location: anywhere in oral cavity

-age: older adults

-clinical features: expanding mass that may or may not be painful or ulcerated

-histology: fascicles of pleomorphic and spindle-shaped cells forming a “storiform” (pin-wheel) pattern

-treatment and prognosis: radical surgical excision, 40% recurrence, 40% metastasis within 2 yrs, poor survival especially for oral tumors

synovial sarcoma

-sarcoma of unknown origin, does not arise from synovium!!

-translocation between the X chromosome and chromosome 18; SYT-SSX fusion gene

-location: tongue, cheek

-age: teenagers and young adults, M>F

-clinical features: gradually enlarging mass associated with pain or tenderness

-histology: mostly biphasic with spindle cells and cuboidal to columnar epithelial cells that surround gland-like spaces or form nests, cords, or whorls

-treatment and prognosis: surgical excision and adjunctive radiation therapy or chemotherapy, high rates of recurrence and metastasis, 20-38% 10yr survival

alveolar soft-part sarcoma

-malignant tumor of uncertain origin

-translocation t(X;17)(p11.2;q25), ASPL-TFE3 fusion gene

-location: ~25% of all cases occur in the H&N, tongue = most frequent oral location

-age: young adults and children

-gender: 2x more common in female (1-20yo), male predilection for those developing after 30 yrs of age

-clinical features: slow-growing painless mass

-histology: alveolar collections of large, polygonal cells with granular cytoplasm

-treatment and prognosis: surgical excision + radiation or chemotherapy, poor prognosis due to late metastasis, 60% 5yr survival, >15% 20yr survival, better for young patients