Bone marrow tryptase as a possible diagnostic criterion for adult systemic mastocytosis.

BACKGROUND: Mastocytosis is difficult to diagnose, especially when systemic mast cell activation symptoms are not present or involve only one extracutaneous organ. OBJECTIVE: The main objective was to evaluate the accuracy of the bone marrow tryptase level in the diagnosis of systemic mastocytosis in patients with a clinical suspicion of mastocytosis. METHODS: We included all adult patients evaluated in our centre between December 2009 and 2013 for suspected mastocytosis as part of a standardized procedure and who had a bone marrow and serum tryptase assay on the same day. The diagnosis of systemic mastocytosis was established on the basis of the World Health Organization criteria as the gold standard. The accuracy of the bone marrow tryptase level in the diagnosis of systemic mastocytosis was assessed by a receiver operating characteristics curve analysis. The different sensitivity and specificity values, corresponding to the set of possible bone marrow tryptase level cut-off values, were estimated with 95% confidence intervals. RESULTS: Seventy-three patients were included. The diagnosis of systemic mastocytosis was established in 43 patients (58.9%). The median bone marrow tryptase level was 423 µg/L [95% CI: 217-868] in the systemic mastocytosis group and 7.5 µg/L [95% CI: 4.6-17.1] in the non-systemic mastocytosis group (P < 0.001). A cut-off value of 50 µg/L for bone marrow tryptase identified systemic mastocytosis with a sensitivity of 93.0% [95% CI: 80.9-98.5%] and a specificity of 90.0% [95% CI: 73.5-97.9%]. CONCLUSION AND CLINICAL RELEVANCE: The bone marrow tryptase level appears to be a valuable diagnostic criterion for confirming systemic mastocytosis. If this diagnosis can reliably be excluded by evaluation of the bone marrow tryptase level, there would be no need to perform a bone marrow biopsy.

Sentinel lymph node biopsy for melanoma is becoming a consensus: a national survey of French centres involved in melanoma care in 2008.

BACKGROUND: The role of sentinel lymph node (SLN) biopsy in melanoma care remains controversial and is not included in most guidelines for the management of melanoma in Europe. OBJECTIVE: To evaluate the practice of SLN biopsy for melanoma. METHODS: In 2008, a self-administered questionnaire was mailed to physicians in 49 hospitals in France. RESULTS: Questionnaires were returned by 34 (69.3%). A median number of 90 new cases of melanoma were treated each year per centre. SLN biopsy was performed routinely in 21 (61.7%) centres. The practice of SLN biopsy for melanoma was recommended in the local guidelines in 53% of centres. The proportion of patients reported as undergoing SLN biopsy for melanoma was significantly higher in centres with local guidelines than in centres without local guidelines (33.4 ± 21.4% vs. 13.1 ± 21.8%; P = 0.003). Where the local guidelines recommended SLN biopsy (n = 21), it was advocated in the case of Breslow thickness ≥1.0 mm (76%) and/or ulceration of the primary melanoma (38%) and/or histological regression of the primary melanoma (24%). CONCLUSION: Our study may be considered representative of SLN practice in France. Contrary to current national guidelines for melanoma care in France, SLN biopsy is routinely recommended in the majority of centres. Our study shows that the practice of SLN biopsy for melanoma is increasingly performed in patients with intermediate Breslow melanoma.