Diagnosis Of Mastocytosis Research Articles

Quantification of cutaneous mast cells using morphometric point counting and a conjugated avidin stain

Mast cells in normal human skin and in lesional cutaneous tissue from two patients with mastocytosis were quantified with the use of a morphometric point counting technic in combination with the mast cell-specific stain, conjugated avidin. Mast cells in normal human flank skin occupied a relatively small percentage of the dermal volume, with a mean value of 0.40% (+/- 0.14 SD), while a marked increase in mast cell content was demonstrated in cutaneous lesional tissue from two patients with the macular and nodular forms of mastocytosis (2.5% and 64.3%, respectively). In a comparative study with the use of morphometric analysis, conjugated avidin proved objectively to be as good as toluidine blue, and subjectively superior to this stain for mast cell identification in both human and murine skin. The combination of morphometric point counting and the conjugated avidin stain provides a useful tool for establishing the diagnosis of mastocytosis and is applicable to a variety of experimental systems.

The Spectrum of Mastocytosis

Mastocytosis represents a spectrum of clinical disorders that results from an aberrant proliferation of tissue mast cells. This disease process may be confined to the skin (cutaneous mastocytosis) or may involve multiple organs (systemic mastocytosis). Parameters that are useful in differentiating cutaneous from systemic disorders include patient age, symptom complex, and clinical signs. A wide range of clinical symptoms may be encountered in patients with mastocytosis which result from the release of pharmacologically potent mast cell mediators. Distinct cutaneous patterns resulting from skin mast cell infiltrates can be helpful in identifying patients with systemic involvement. The diagnosis of mastocytosis is confirmed by demonstrating increased tissue mast cells in involved organs. The overall prognosis for patients with proliferative mast cell disease is relatively good, although a small percentage are at risk for developing a fatal neoplastic disorder (malignant mastocytosis). Treatment of mastocytosis is directed at both inhibiting mast cell degranulation and blocking the potential systemic effects of released secretory products. Future therapeutic advances depend upon an improved understanding of the basic mechanisms involved in mast cell mediator release and the forces that govern mast cell growth and development.

Improved diagnosis of mastocytosis by measurement of urinary histamine metabolites

Improved diagnosis of mastocytosis by measurement of urinary histamine metabolites

Improved diagnosis of mastocytosis by measurement of urinary histamine metabolites.

In an attempt to facilitate the diagnosis of mastocytosis, we measured the urinary excretion of histamine and two of its main metabolites (N tau-methylhistamine and N tau-methylimidazoleacetic acid) in eight adults with this disorder. All patients had above-normal values for the metabolites of histamine, whereas only three had above-normal values for histamine. In both 24-hour and randomly voided urine specimens, the determination of histamine metabolites is more specific and sensitive for the diagnosis of mastocytosis than the determination of histamine itself.

Systemic mastocytosis. Extracutaneous manifestations.

The clinical, radiologic, ultrastructural, and histopathologic findings in 14 patients with systemic mastocytosis were evaluated. Seven patients had evidence of urticaria pigmentosa (UP) and seven patients presented with no recognizable cutaneous lesions. There were no major clinical differences between patients with or without UP except for splenomegaly, which was present in one/seven patients with UP and five/seven patients without UP and the median age, 44 in patients with UP, and 75 in patients without UP. Bone marrow involvement was present in 13/13 specimens studied. Involvement was both focal and diffuse. The focal involvement occurred frequently in a perivascular and paratrabecular location. The diffuse involvement resembled myelofibrosis. Involved lymph nodes exhibited prominent sinusoidal and paracortical infiltration by mast cells. Splenic involvement was characterized by fibrosis occurring both focally and diffusely. The focal splenic involvement was perivascular and involved both the red and white pulp in a nonpreferential manner. Liver specimens showed prominent portal fibrosis. The morphology of the mast cells in the different lesions varied considerably; some were typical, others were spindle-shaped, and some resembled histocytes. The mast cells reacted positively with toluidine blue and chloroacetate esterase. Six patients had radiologic changes: three were osteoblastic, two osteolytic, and one osteoblastic and osteolytic. Two patients developed a poorly differentiated lymphoreticular tumor and one a myeloproliferative disorder after the diagnosis of mastocytosis.

Mastocytosis with Skeletal and Gastrointestinal Involvement in Infancy

Two cases of mastocytosis with skeletal involvement in children three and six months old are reported. Bone lesions, either sclerotic or lytic, were encountered in their skeletal surveys. Gastrointestinal lesions in children with mastocytosis are exceedingly rare; in addition to skeletal lesions, one of our patients had a large duodenal ulcer. The diagnosis of mastocytosis was established by skin biopsy in both patients. A review of the literature is also presented.