[1361] Histiocytic and Dendritic Cell Neoplasms: A Clinicopathologic Study of 15 Cases.

Reza Setoodeh, Lynn Moscinski, Lubomir Sokol, Mojdeh Naghashpour. Moffitt Cancer Center, Tampa, FL

Background: Histiocytic and dendritic cell neoplasms are rare hematopoietic tumors. Diagnostic criteria include morphologic and immunophenotypic evidence of histiocytic or dendritic cell differentiation and exclusion of other hematopoietic and non-hematopoietic tumors.
Design: Clinicopathological features of fifteen consecutive cases of Histiocytic Sarcoma (7/15), Langerhans Cell Tumor (4/15), Interdigitating Dendritic Cell Sarcoma (IDC) (2/15), Indeterminate Cell Histiocytosis (1/15), and Reticulum Dendritic Cell Tumor (1/15) from pathology files at Moffitt Cancer Center were retrieved. Morphologic, phenotypic, sites of involvement and clinical features were reviewed.
Results: Histiocytic sarcoma revealed sheets of non-cohesive large epithelioid cells with irregular nuclei, vesicular chromatin and abundant eosinophilic cytoplasm, with variable degrees of pleomorphism, and reactivity for CD68, lysozyme, and CD163 immunostains. IDC sarcoma cases showed sheets of spindled cells with vesicular chromatin and marked cytologic atypia, positive for S-100 and Vimentin immunostains. Langerhans cell tumors were composed of large cells with grooved and folded nuclei, fine chromatin, inconspicuous nucleoli, and moderately abundant eosinophilic cytoplasm, with variable degrees of nuclear atypia, positive for CD68, CD1a and S-100. Indeterminate cell tumor was composed of large cells with abundant cytoplasm and oval to spindled-shape nuclei, and positive reactivity for S-100, CD68, and CD1a immunostains. Reticulum Dendritic Cell tumor showed effacement of the nodal architecture by sheets of spindled cells in storiform pattern, that were positive for S100, actin, and CD45 immunostains. Primary sites of involvement were extranodal in eleven cases and nodal in four. Bone marrow was involved in three cases which all were histiocytic sarcomas. Eleven patients underwent surgical resection of which four received adjuvant chemotherapy. Three patients with histiocytic sarcoma died 12 to 48 months after first diagnosis. Survival ranged from 4 to 168 months.
Conclusions: Our experience confirms frequent involvement of extranodal sites (11/15) in these tumors. Diagnosis requires a combination of morphologic and immunophenotypic assessment, utilizing a battery of immunohistochemical stains. Raising awareness of histiocytic and dendritic cell subtypes is important, as clinical course are significantly varied. Our experience also confirms that histiocytic sarcoma has more propensity to involve the bone marrow. Surgical resection remains the mainstay of treatment, with yet undefined role for additional chemoradiation therapy.
Category: Hematopathology

Tuesday, March 1, 2011 9:30 AM

Poster Session III # 234, Tuesday Morning


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