MASTOCYTOSIS TYPE IV

Leukemic Mastocytosis; Mast Cell Leukemia; MCL; Lymphadenopathic Mastocytosis; Mast Cell Sarcoma

Mastocytosis is a rare neoplastic disorder that occurs when there is an abnormal accumulation (excess) of mast cells in the blood and bone marrow, skin, gastrointestinal tract (GI), liver and spleen. Mastocytosis can be cutaneous (skin) or systemic (involving the internal organs of the body). Depending on the number of mast cells in the different organ parts, it is classified as either indolent (slow growing) or aggressive.

People with Mastocytosis Type IV have mast cell leukemia. Type IV is the most severe form of mastocytosis marked by malignant proliferation of mast cells in the blood, no skin involvement, multi-organ failure, and a short survival. Type IV is generally defined as having at least 10% abnormal mast cells in the peripheral blood or at least 20% abnormal mast cells in the bone marrow.

Diagnostic testing: Diagnostic testing for Mastocytosis Type IV includes:

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  Skin exam;

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  Bone marrow biopsy;

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  Plasma tryptase; and

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  Urine mediators such as histamine.

Imaging testing can include skeletal survey and gastrointestinal evaluation. Bone scans and bone marrow testing are conclusive.

Physical findings: Signs and symptoms of this condition include:

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  Anemia and bleeding disorders;

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  Gastrointestinal symptoms such as abdominal pain, diarrhea, nausea, or vomiting;

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  Itching, hives, or flushing of the skin;

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  Anaphylactoid reactions;

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  Enlarged liver (hepatomegaly);

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  Enlarged spleen (splenomegaly); and

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  Enlarged lymph nodes (lymphadenopathy).

ICD-9: 202.6

The median age at diagnosis of the severe form of mastocytosis in adults is 55 years of age. Type IV has also occurred in children as young as 4 years old. The prognosis for people with type IV mastocytosis is poor with survival time of a few months once the diagnosis is established.

There is no current cure or standard treatment for mastocytosis type IV. Severe forms of mastocytosis have been treated with chemotherapy, immunotherapy, stem cell or bone marrow transplantation.

SUGGESTED PROGRAMMATIC ASSESSMENT*

Suggested MER for Evaluation:

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  A thorough history of illness;

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  Oncology, hematology, dermatology, and immunology consultation reports;

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  Pathology reports; and

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  Imaging study reports.

Suggested Listings for Evaluation:

REMARKS

Mastocytosis Type IV meets the criteria in listing 13.06 A upon confirmed diagnosis, regardless of effectiveness of treatment.