Systemic mastocytosis mimicking carcinoid syndrome

The Diagnosis of Neuroendocrine Tumours: An Endocrine Perspective

“…If CS is excluded, 24-hour urinary metanephrine and normetanephrine, serum calcitonin, and serum total tryptase levels for systemic mastocytosis, should be measured. In general, total tryptase levels are greater than 20 ng/mL in systemic mastocytosis and this is a minor criterion in WHO diagnostic criteria for systemic mastocytosis (50). However, in cutaneous mastocytosis, monoclonal mast cell activation syndrome and systemic mastocytosis limited to bone marrow, tryptase values may be lower (45).…”

“…In medullary thyroid carcinoma (MTC) the most prominent hormone-mediated symptom is secretory diarrhoea with or without flushing (48). In systemic mastocytosis, in addition to flushing pruritus, nausea, diarrhoea, abdominal pain and even vasodilatory shock may occur due to the release of mast cell mediators (45,50). Table 1 summarises a number of secretory products and associated symptoms which will not be discussed here in detail.…”

Cutaneous mastocytosis: A dermatological perspective

“…Clinical features of both these conditions can overlap, and both seem to respond to somatostatin analogue treatment. Nevertheless, negative imaging, bone marrow biopsy and high levels of serum tryptase can simplify the differential diagnosis 32 …”

“…Nevertheless, negative imaging, bone marrow biopsy and high levels of serum tryptase can simplify the differential diagnosis. 32 Although systemic symptoms are more frequently seen in adult patients as a consequence of the presumably systemic progression of the disease, in children there is a higher risk of anaphylaxis due to the massive release of mast cells mediators. 22 The incidence and severity of anaphylaxis are 4 to 6 times higher in patients with mastocytosis compared with that in the general population.…”