Tuesday, January 15, 2008

How to Diagnose Histiocytoma


A histiocytoma is a tumor composed of the macrophages in connective tissue called histiocytes. A malignant fibrous histiocytoma (MFH) is the most common sarcoma of soft tissue in elderly patients and usually occurs in the extremities. The classification of histiocytomas is controversial because of their classification by histology and uncertain origin. The following subtypes are described: angiomatoid, giant cell, inflammatory, myxoid and storiform/pleomorphic (the most common.)


Difficulty: Challenging



Step One

Observe the first symptoms of a histiocytomas to be a soft tissue mass typically 5 to 10 cm in diameter, usually on the thigh. It is usually painless and two thirds of histiocytomas are intramuscular. Histiocytomas may cause hypoglycemia and occasionally enlarge rapidly during pregnancy.

Step Two

Find the constitutional symptoms associated with retroperitoneal MFH including fatigue, fever and weight loss. The tumor is usually larger than 10 cm by the time the patient is examined. A soft tissue mass that does not have fat in the extremity of an elderly patient is usually a histiocytoma.

Step Three

Use Magnetic Resonance Imaging (MRI) as the imaging technique of choice for histiocytomas. An MRI is helpful in defining the extent of the tumor. However, the signal characteristics of a histiocytoma are usually non-specific, making a biopsy necessary.

Step Four

Perform an axial Computed Tomography scan as an alternative if the patient has metal implants or is claustrophobic. CT is also helpful for evaluating calcifications.

Step Five

Make the diagnosis with a histological examination of a biopsy.

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