Primary histiocytic sarcoma of the brain mimicking cerebral abscess

Case report

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Histiocytic sarcoma is a rare malignancy with only 10 reports confirmed primarily involving the CNS. The diagnosis is dependent on the finding of malignant cells with histiocytic morphology and immunophenotype. The authors report a case of pathologically proven HS of the CNS. A 16-year-old boy presented with headaches, emesis, and altered sensorium. Noncontrast head CT scanning demonstrated a left parietal mass consistent with a tumor. Surgery was undertaken. Intraoperative findings revealed green-yellow exudates consistent with an abscess. Cultures were obtained and broad-spectrum antibiotics were started. The patient subsequently underwent multiple surgical procedures, including drainage and debulking of abscesses and hemicraniectomy. Two months after initial presentation, the patient's diagnosis of histiocytic sarcoma was confirmed. Pathological examination demonstrated necrotizing inflammation with preponderant neutrophil infiltration, variably atypical mononuclear and multinucleate histiocytes, and numerous mitoses. Additional immunohistochemistry studies confirmed immunoreactivity for CD68, CD45, CD45RO, and CD15 and were negative for CD3, CD20, melanoma cocktail, CD30, CD1a, CD34, HMB-45, and melan-A. Once the diagnosis of histiocytic sarcoma was confirmed, antibiotics were stopped and radiation therapy was undertaken. Despite treatment, the patient's neurological status continued to decline and the patient died 126 days after initial presentation.

This case represents a rare confirmed example of CNS histiocytic sarcoma. A profound inflammatory infiltrate seen on pathology and green exudates seen intraoperatively make the condition difficult to distinguish from an abscess. Immunohistochemistry showing a histiocytic origin and negative for myeloid, dendritic, or other lymphoid markers is essential for the diagnosis. Further research is needed to establish consensus on treatment.

Abbreviation used in this paper:HS = histiocytic sarcoma.

Article Information

Address correspondence to: Peter Nakaji, M.D., Neuroscience Publications, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, 350 W. Thomas Rd., Phoenix, AZ 85013. email:

Please include this information when citing this paper: published online July 26, 2013; DOI: 10.3171/2013.6.PEDS12533.

© AANS, except where prohibited by US copyright law.



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    Left: Axial T1-weighted Gd-enhanced MR image of the brain at initial presentation showing a left parietal multiloculated mass with local vasogenic edema. Right: The loculations are diffusion restricted and intraoperatively were found to be full of a purulent fluid.

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    Intraoperative photograph demonstrating the purulent fluid. Used with permission from Barrow Neurological Institute.

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    Left: The abscess-like areas were filled with purulent necrotic debris. Right: Atypical large, often bizarre “discohesive” cells with folded nuclei and abundant granular cytoplasm. Scattered neutrophils and small mononuclear inflammatory cells are present in the background. H & E, original magnification × 400.

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    Eighteen days after initial presentation, the mass has enlarged substantially despite internal drainage and an aggressive course of antibiotics.

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    The mass is even larger, despite another drainage and debulking procedure and additional antibiotics.

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    Left: The atypical cells express CD-68 consistent with a histiocytic origin. Note that CD68 positivity is not sufficient to prove the diagnosis. The tumors must also be CD45 positive and negative for other lymphocyte specific markers, myeloid markers, and markers of different histiocytic lineages such as Langerhans cells. Right: The atypical cells also express CD45, a pan-lymphocytic and monocyte lineage marker. DAB with hematoxylin, original magnification × 200.

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    A: Four months after initial presentation, the mass has grown substantially despite a course of radiation therapy. B: Metastatic deposits are now seen in both hemispheres and the posterior fossa. C: The loculations continue to be strongly diffusion restricted.



Bell SLHanzely ZAlakandy LMJackson RStewart W: Primary meningeal histiocytic sarcoma: a report of two unusual cases. Neuropathol Appl Neurobiol 38:1111142012


Cao MEshoa CSchultz CBlack JZu YChang CC: Primary central nervous system histiocytic sarcoma with relapse to mediastinum: a case report and review of the literature. Arch Pathol Lab Med 131:3013052007


Cheuk WWalford NLou JLee AKFung CFAu KH: Primary histiocytic lymphoma of the central nervous system: a neoplasm frequently overshadowed by a prominent inflammatory component. Am J Surg Pathol 25:137213792001


Devic PAndrodias-Condemine GStreichenberger NBerger FHonnorat JBroussolle E: Histiocytic sarcoma of the central nervous system: a challenging diagnosis. QJM 105:77792012


Egeler RMSchmitz LSonneveld PMannival CNesbit ME: Malignant histiocytosis: a reassessment of cases formerly classified as histiocytic neoplasms and review of the literature. Med Pediatr Oncol 25:171995


Hsu SMHo YSHsu PL: Lymphomas of true histiocytic origin. Expression of different phenotypes in so-called true histiocytic lymphoma and malignant histiocytosis. Am J Pathol 138:138914041991


Louis DNOhgaki HWiestler ODCavenee WK: WHO Classification of Tumours of the Central Nervous System ed 4LyonIARC Press2007


Low SEStafford JS: Malignant histiocytosis: a case report of a rare tumour presenting with spontaneous splenic rupture. J Clin Pathol 59:7707722006


Mainardi CD'Amore ESPillon MToffolutti TRosolen A: A case of resistant pediatric histiocytic sarcoma successfully treated with chemo-radiotherapy and autologous peripheral blood stem cell transplant. Leuk Lymphoma 52:136713712011


Pileri SAGrogan TMHarris NLBanks PCampo EChan JK: Tumours of histiocytes and accessory dendritic cells: an immunohistochemical approach to classification from the International Lymphoma Study Group based on 61 cases. Histopathology 41:1292002


Robb-Smith AHT: Reticulosis and reticulosarcoma: a histological classification. J Pathol 47:4574801938


Sun WNordberg MLFowler MR: Histiocytic sarcoma involving the central nervous system: clinical, immunohistochemical, and molecular genetic studies of a case with review of the literature. Am J Surg Pathol 27:2582652003


Torres CFKorones DNPowers JMVadasz AG: Primary leptomeningeal histiocytic lymphoma in a young child. Med Pediatr Oncol 27:5475501996


Toshkezi GEdalat FO'Hara CDelalle IChin LS: Primary intramedullary histiocytic sarcoma. World Neurosurg 74:5235272010


Vos JAAbbondanzo SLBarekman CLAndriko JWMiettinen MAguilera NS: Histiocytic sarcoma: a study of five cases including the histiocyte marker CD163. Mod Pathol 18:6937042005


Yu LYang SJ: A case of primary histiocytic sarcoma arising from thyroid gland. Pathol Oncol Res 16:1271322010




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