Muscular Lesions Flashcards
A muscular reactive lesion
Myositis ossificans
Location of myositis ossificans
Sternocleidomastoid, masster
Muscular lesion in neoplasm origin
Leiomyoma/leiomyosarcoma
Rhabdomyoma/rhabdomyosarcoma
IHC profile for skeletal lesions
+ myogenin , myoglobin , desmin
- smooth muscle actin , calponin
IHC profile for smooth muscle lesion
+ desmin , smooth muscle actin , calponin
- myogenin , myoglobin
Location of leiomyoma/sarcoma
Non-specific, blood vessels
Location of rhabdomyoma/sarcoma
Floor of the mouth , soft palate , tongue , buccal mucosa , masticatory muscle
Uncommon reactive lesion of skeletal muscle
Myositis ossificans
Myositis ossificans is an ____ inflammatory process in which ossification occurs
Intramuscular
Two forms of myositis ossificans
Progressive systemic disease ( myositis ossificans progresiva )
Focal single - muscle disorder ( traumatic myositis ossificans )
Etiology of Progressive systemic disease ( myositis ossificans progresiva )
Unknown cause
Etiology of Focal single - muscle disorder ( traumatic myositis ossificans )
Acute or chronic trauma
Most common location of myositis ossificans in the head and neck region
Sternocleidomastoid and masseter
Radiographic feature of myositis ossificans
Delicate feathery opacification
Essential diagnostic feature of myositis ossificans
Maturation and organization of the osseous tissue peripheral to the central cellular zone
Treatment for myositis ossificans
Surgical excision
Little tendency to recur
Most common arise from leiomyosarcoma
In the retroperitoneum, mesentery, omentum or subcutaneous and in deep tisues of the limbs
Most common arise of leiomyomas
Muscularis layer of the gut and in the body of the uterus
Presents as slow-groing, asymptomatic subucosal masses
Usually in the tongue, hard palate or buccal mucosa
Sinonasal tract, mandible
Any age
Leiomyomas
Subtype of leiomyoma
Angioleiomyoma (vascular leiomyoma)
Treatment for leiomyomas
Surgically excised, recurrence is unexpected
A small cytoplasmic filament, about 5nm in diameter that has contractile properties
Actin
Treatment for leiomyosarcomas
Wide surgical excision + chemo/radio
Distant metastasis to lungs (50%)
Clinical features of leiomyoma
Soft tissue swelling
1% leiomyoma are located in H&N
- 12-15% are angioleiomyomas
M=F predilection
20% 5-year survival rate
Leiomyosarcoma
50% of case, distant metastasis to lungs
Leiomyosarcoma
Bland, spindled tumor cells are arranged in intersecting fascicles. Cells are oval to elongated with cigar-shaped nuclei, without atypia. Mitoses are absent to sparse
Leiomyoma
Histopathological feature of leiomyoma
Bland, spindled tumor cells are arranged in intersecting fascicles. Cells are oval to elongated with cigar-shaped nuclei, without atypia. Mitoses are absent to sparse
Histopathological features of angioleiomyoma
Prominent vasculature surrounded by smooth muscle cells associated with vessels
Prominent vasculature surrounded by smooth muscle cells associated with vessels
Angioleiomyoma
IHC profile for leiomyoma
Desmin
HMB45
Essential diagnostic rieria of leiomyosarcoma or angioS
Fascicles of eosinophilic spindled cells with blunt ended nuclei with variable pleomorphism and mitoses
Fascicles of eosinophilic spindled cells with blunt ended nuclei with variable pleomorphism and mitoses
Leiomyosarcoma / angiosarcoma
Localization of rhabdomyoma
Momuth and soft tissues of the neck
Parapharyngeal space, salivary glands, larynx
Two types of rhabdomyoma
Adult type (ARM)
Fetal typee (FRM)
Age and gender predilection for the two types of rhabdomyoma
ARM - 60yo , M:F = 3:1
FRM - 4.5-60yo , M:F = 5:1
Histopathological features of rhabdomyoma
For ARM and FRM
ARM: large polygonal cells having abundant eosinophilic, granular or vacuolated cytoplasm (spider cells) with focal cross striation or crystalline (rod-like or jack straw like) inclusion
FRM: primitive round to spindle cells and myotube-like rhabdomyoblasts with eosinophilic cytoplasm and cross-striations set in a myxoid matrix
IHC for rhabdomyoma
Myogenin
Desmin
Myoglobin
Treatment for rhabdoymyoma
Complete excision
No metastasis
Subtype of rhabdomyosarcoma thatt occurs in children
Embryonal and alveolar
Histopathological feature
Primitive round to spindle cells, with scant cytoplasm and hyper chromatic nuclei, scattered rhabdomyoblasts
Embryonal rhabdomyosarcoma
Histopathological feature
Fibrovascular septa separating cellular nests of small sized monomorphic round cells with scant cytoplasm, rhabdoid
Alveolar rhabdomyosarcoma
Histopathological feature
Fasciculated proliferation of spindle cells with elongated nuclei and pale indistinct cytoplasm, with interspersed spindled or polygonal rhabdomyoblasts with abundant, brightly eosinophilic cytoplasm
Spindle rhabdomyosarcoma
Treatment for rhabdomyosarcoma
Surgical excision, chemo/radio
Most adult patients are stage IV at presentation
RMS poor prognosis (40-45% 5-year survival rate)
Subtype of rhabdomyosarcoma that has an excellent prognosis
Spindle ell and botryoid type
When it occurs in the head and neck region, it is typically seen in children. When it occurs outside, it is typically seen in adults
Rhabdomyosarcoma
Rapidly growing mass that may cause pain or paresthesia if jaw involvement ocurs.
Rhabdomyosarcoma
The most common subtype of rhabdoymyosarcoma
Embryonal type
IHC for rhabdoymosarcoma
Desmin , acting , myogenin , myoD1
Two consistent and reproducible chromosome translocation that is associated with alveolar rhabdomyosarcoma
T(12:13) (q35;q14)
And
T(1:13)(p36q14) - less common
These translocation juxtapose the PAX3 or PAX7 gene on chromosomes 2 and 1
