TY - JOUR
T1 - Validation of dermatopathological criteria to diagnose cutaneous lesions of mastocytosis
T2 - importance of KIT D816V mutation analysis
AU - Gebhard, J.
AU - Horny, H. P.
AU - Kristensen, T.
AU - Broesby-Olsen, S.
AU - Zink, A.
AU - Biedermann, T.
AU - Brockow, K.
N1 - Publisher Copyright:
© 2022 The Authors. Journal of the European Academy of Dermatology and Venereology published by John Wiley & Sons Ltd on behalf of European Academy of Dermatology and Venereology.
PY - 2022/8
Y1 - 2022/8
N2 - Background: Cutaneous lesions of mastocytosis (CLM) are often subtle and may require biopsy. However, dermatohistopathological criteria for CLM remain undefined. Objectives: To establish criteria for CLM by validating histological and molecular parameters. Methods: In skin samples from Caucasian patients with CLM and controls (atopic dermatitis, chronic urticaria, pruritus, tissue from tumor safety margin excisions), mast cell (MC) numbers, size, shape, distribution, immunostainability with a large panel of markers, pigmentation and presence of KIT D816V mutation were analysed. Results: Forty-seven CLM patients (32 maculopapular cutaneous mastocytosis (MPCM), 15 mastocytomas) and 36 controls were included. Mastocytomas were easily identified by densely packed cuboidal MCs. In MPCM, skin MC density in CD117 stains was higher in CLM patients than in controls (P < 0.0001) and values correlated closely (r = 0.65, P < 0.0001) to results in tryptase stains. The optimized upper dermis cut-off number of 62 MC/mm2 had a sensitivity and specificity of 92% in both stainings, corresponding to approximately 12 MC/high power field (HPF). MC size was larger in MPCM than in controls (P = 0.01). Interstitial (= not perivascular or periadnexal) MCs and stronger basal pigmentation of the epidermis were indicative of MPCM (P < 0.0001 each) and clusters of >3 nucleated MC/HPF exclusively found in MCPM. Surface markers CD2, CD25 and CD30 stained T-lymphocytes, but only negligibly CLM MC. The KIT D816V mutation in formalin fixed paraffin embedded (FFPE) skin was evaluable in 87.5% of MCPM patients and had both 100% sensitivity and specificity. Conclusions: MPCM can be predicted by major and minor criteria combined in a scoring model. Presence of D816V mutation in FFPE skin and MC density > 27/HPF are >95%-specific major criteria for MPCM. MC densities 12/HPF, interstitial MC, clusters and basal pigmentation are minor criteria.
AB - Background: Cutaneous lesions of mastocytosis (CLM) are often subtle and may require biopsy. However, dermatohistopathological criteria for CLM remain undefined. Objectives: To establish criteria for CLM by validating histological and molecular parameters. Methods: In skin samples from Caucasian patients with CLM and controls (atopic dermatitis, chronic urticaria, pruritus, tissue from tumor safety margin excisions), mast cell (MC) numbers, size, shape, distribution, immunostainability with a large panel of markers, pigmentation and presence of KIT D816V mutation were analysed. Results: Forty-seven CLM patients (32 maculopapular cutaneous mastocytosis (MPCM), 15 mastocytomas) and 36 controls were included. Mastocytomas were easily identified by densely packed cuboidal MCs. In MPCM, skin MC density in CD117 stains was higher in CLM patients than in controls (P < 0.0001) and values correlated closely (r = 0.65, P < 0.0001) to results in tryptase stains. The optimized upper dermis cut-off number of 62 MC/mm2 had a sensitivity and specificity of 92% in both stainings, corresponding to approximately 12 MC/high power field (HPF). MC size was larger in MPCM than in controls (P = 0.01). Interstitial (= not perivascular or periadnexal) MCs and stronger basal pigmentation of the epidermis were indicative of MPCM (P < 0.0001 each) and clusters of >3 nucleated MC/HPF exclusively found in MCPM. Surface markers CD2, CD25 and CD30 stained T-lymphocytes, but only negligibly CLM MC. The KIT D816V mutation in formalin fixed paraffin embedded (FFPE) skin was evaluable in 87.5% of MCPM patients and had both 100% sensitivity and specificity. Conclusions: MPCM can be predicted by major and minor criteria combined in a scoring model. Presence of D816V mutation in FFPE skin and MC density > 27/HPF are >95%-specific major criteria for MPCM. MC densities 12/HPF, interstitial MC, clusters and basal pigmentation are minor criteria.
UR - http://www.scopus.com/inward/record.url?scp=85128908882&partnerID=8YFLogxK
U2 - 10.1111/jdv.18143
DO - 10.1111/jdv.18143
M3 - Article
C2 - 35412687
AN - SCOPUS:85128908882
SN - 0926-9959
VL - 36
SP - 1367
EP - 1375
JO - Journal of the European Academy of Dermatology and Venereology
JF - Journal of the European Academy of Dermatology and Venereology
IS - 8
ER -