FDCS; Follicular Dendritic Cell Sarcoma; Histiocytic Sarcoma; Interdigitating Dendritic Cell Sarcoma; IDCS; Langerhans Cell Sarcoma; LCS

Histiocytic malignanices are very rare cancers that arise from histiocytes, dendritic cells, and Langerhans cells. These tumors are highly malignant and rapidly progressive. Because the cancers are so rare, their therapy is not standardized, and tends to be only minimally to moderately effective. The tumors most commonly present with lesions in soft tissue and skin but rapidly advance to involve lymph nodes and organ tissues. These cancers present in middle-aged and older adults and are very rarely seen in children.

Types of histiocytic malignancies include:

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  Langerhans cell sarcomas (LCS);

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  Interdigitating dendritic cell sarcomas (IDCS);

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  Histiocytic sarcomas (the most common form of histiocytic malignancy); and

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  Follicular dendritic cell sarcoma (FDCS).

LCS is an extremely aggressive high-grade tumor that can occur without a known cause. It can also progress from Langerhans Cell Histiocytosis. These tumors usually involve the skin and underlying soft tissue. Although rare, it may also involve the lungs, liver, spleen, and bone. LCS can occur at any age but is most commonly diagnosed in adults over 45 years of age.

IDCS arises from antigen presenting cells. It mostly affects the lymph nodes. Although rare, it can also occur in skin and soft tissue. IDCS can occur at any age but is most commonly diagnosed in adult males over 60 years of age.

Histiocytic sarcoma is an aggressive cancer with an unknown cause. Tumors commonly occur in the intestinal tract, skin, and soft tissue. Histiocytic sarcoma can occur at any age but are most common in adults over 45 years old.

FDCS is cancer with painless, slow-growing tumors that most commonly occur in the lymph nodes (most often cervical), extranodal sites (such as tonsils, gastrointestinal tract, soft tissue, mediastinum, or lung, among others), or both. FDCS can occur at any age and is most common in adults aged 50 years and older.

Diagnostic testing: Evidence of a rapidly progressing tumor is mandatory for a diagnosis of histiocytic malignancies. Diagnosis can be very difficult because the conditions can mimic other disorders. The diagnostic work-up for these disorders may include:

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  Tumor biopsy and detailed pathological evaluation, which could include immunophenotyping and genetic/DNA analysis as well as microscopic histology; and

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  Imaging such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) scans, used to determine extent of disease and help with diagnosis.

Physical findings: The symptoms and signs of histiocytic malignancies depend on the type and specific organ involvement. Symptoms and signs of histiocytic malignancies may include:

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  Tumor masses in the skin, soft tissues, and lymph nodes;

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  Fever;

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  Sweats;

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  Weight loss; and

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  Anorexia (lack or loss of appetite).

ICD-9: 202.3; 202.9

ICD-10: C96A; C96.4

Histiocytic malignancies are associated with a very poor prognosis. Survival is generally measured as months to 1-2 years. Patients with early stage localized disease can have better survival with aggressive therapy.

Local sarcoma can be treated with surgery and radiation, with the literature reporting potentially good results. Aggressive chemotherapy, using lymphoma regimens, can improve survival but relapse and death within 1-2 years is still common.

Suggested MER for Evaluation:

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  Clinical history, physical exam, and treatments given;

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  Biopsy results; and

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  Imaging results from CT, MRI, PET scans.

Suggested Listings for Evaluation:

REMARKS

Histiocytic malignancies meet 13.04 if the cancer fulfills the A or B criteria of the sarcoma listing.

Histiocytic malignancies with severe multi-system, multi-focal spread that is being treated with chemotherapy may equal the criteria for listing 13.05 A 1.

Histiocytic malignancies with bone involvement may equal the criteria of listing 13.11.