Review -Unusual orbital tumor- 2012.5.24 R3정현진/Pf.양석우

Anatomy of orbits (connective tissue system)

Constrast enhancement pattern(present, absent, homogeneous, heterogeneous) DDx. Enhancement의 특징은 fat suppressed postcontrast T1 weighted images Non enhanced hemorrhagic processes, dens scar tissue, fluid collections, necrotic portions of a tumor Gadolilnium enhanced MRI : assessing of fibrovascularization tissue proggression Well circumscribed orbital tumors: cavernous hemangioma(homogenous enhance) , neurilemmnoma, neurofibroma, fibrous histiocytoma, hemangiopericytoma

Orbital fibrous histiocytoma(1) General consideration - The most common mesenchymal orbital tumor in middle aged - neoplasm composed of fibroblasts and histiocytes - most : benign some : locally aggressive or malignant Clinical feature Upper nasal quadrant mass, slow-growing, relatively firm masses. Sx: proptosis, mass effect, decreased vision, double vision, pain, eyelid swelling, ptosis Diphasic pattern with mainly storiform(matted) composed of fibrous spindle cells along with scattered area showing single or grouped foamy histiocytes spindle-shaped, fibroblast-like cells, and more ovoid, sometimes lipidized histiocytic cells bundles of enlogated fibroblasts Carwheel pattern of intertwining, elongated fibroblasts 주로 보임 Hematoxylin and eosin Malignant : increased amount of lipid c cytoplasmic vacuoles of the tumor cells Vimentin(+), S-100(-)

Orbital fibrous histiocytoma(2) Diagnostic approachs - MRI, CT: well-circumscribed, irregular mass of uniform density - DDx: schwannoma, carvenous hemangioma Pathology - Several variant  diagnostic difficulty - Immunohistry : DDx of spindle cell tumor fibrous histiocytoma: CD34(-) solitary fibrous tumor : CD34 strongly (+) Tx- complete surgical resection d/t possible of recurrence, malignant formation Swannoma: 조직 비슨 : spindle-shaped nuclei in a whirling or fascicular pattern with eosinophilic glassy cytoplasm Gross: a lobulated, well circumscribed, firm, grayish white to yellow tna mass Bx: cartwheel bundles of enlogated fibroblasts c spindle-shaped, uniformly staining nuclei set in a dense fibrous stroma 나누기 benign, intermediate, malignant H&E, original magnification x 200 Figure 3 (above, left and right). Benign fibrous bistioc)toma of orbit displaying the characteristic storiform (cartwheel) pattern. Notice the admixture of fibroblastic and histiocytic-like cells. The latter cells show plump vesicular nuclei. (Left, hematoxylin-eosin stain, x 115. AFIP neg 66-1106. Right, hematoxylin-eosin stain, x305. AFIP neg 66-1107.) Figure 4 (below, left). Benign fibrous histioc)'tonm of orbit with fascicles ofspindle-sbaped cells showing an ill-defined storiform pattern. Focal collection of xantlionlatous cells are present. (ttematoxylin-eosin stain, x 195. AFIP neg 66-8897.) Figure 5 (below, right). Some orbital fibrous histiocytonaas show fi)ci containing bland-appearing muhinucleated giant cells, probably of histiocytic origin. (tlematoxylin-eosin stain, x260. AFIP neg 74-3962.)

Hemangiopericytoma(1) A spectrum of pericyte proliferation Histology - a mixed pattern of ovoid cells and sinusoidal space formation, creating the classic ‘staghorn’ vascular pattern Clinical features - middle-aged adults as slowly progressing unilateral proptosis, often with pain and vision loss, frequent intracranial extension and invasion to sinus cavity

Hemangiopericytoma(2) DDx -MRI T1: well defined hypointense mass T2: less definition -Meningioma, lymphangioma, carvenous hemangiona, schwannoma Treatment - En bloc excision with wide margins d/t high rate of malignant transformation and recurrence - Adjunctive radiation therapy may be of benefits 조직” perivascular massing of pericytes Silver-stained material reveals reticulin

Langerhans cell histocytosis(1) General consideration - Histopathologically chararacterized by proliferation of Langerhans cells - Peak incidence at age 1 and 4 - Those with onset of disease earlier than 1 year of age have worst prognosis -Severity can range from a benign unifocal bone lesion to aggressive multisystem disease Clinical feature -proptosis, redness, mass-like lesion Langerhans cell: large cells with abundant ill-defined cytoplasm, contain typical oval or indented unclei, some of which are shaped like coffee beans with long, central, longitudinal grooves Vimentin(+)HAM(+56) Langerhans CD1a S100(+): positive phenotype CD45(+) Histopathology of the same patients showing the presence of numeorus Langerhans cells suggesting Langerhans cell histiocytosis. A multinucleated giant cell is present (H and E, ×200). (d) The diagnosis of Langerhans cell histiocytosis was confimed with CD1a immunostaining (×200)

Langerhans cell histocytosis(2) Diagnosis -histopathology: presence of langerhans cells, characterized by distinct cell margin and pink granular cytoplasm -CD1a immunstaining or the presence of birbeck granules in electron microscopy Prognosis The tumor cells are quite anaplastic -> Langerhans cell sarcoma. The course of untreated disease is rapidly fatal. With intensive chemotherapy, 50% of patients survive 5 years. 17