Consensus on performing skin biopsies, laboratory workup, evaluation of tissue samples and reporting of the results in patients with suspected cutaneous graft-versus-host disease

BACKGROUND: Histopathological diagnosis including selection of lesions, the determination of the best point of time for biopsy and workup is not trivial in cutaneous graft-versus-host disease (GvHD). OBJECTIVES: To develop interdisciplinary recommendations on performing, the laboratory work up and reporting of the results of skin biopsies in patients with suspected cutaneous GvHD. METHODS: A working group consisting of dermatopathologists, dermatologists, transplant-physicians and transplant-pathologists prepared recommendations for performing skin biopsies, laboratory workup and evaluation of tissue samples, and reporting of the results in patients with cutaneous GvHD. After achieving a consensus within the working group, a survey that comprised the core issues of the recommendations was electronically sent out to 72 alloHSCT centres within Germany, Austria, and Switzerland and their Departments of Pathology. The answers were discussed in a Consensus Conference and final recommendations were established. RESULTS: Twenty-five centres responded to the clinical and 17 centres to the histopathological survey. Questions addressed to the clinicians comprised the indication for skin biopsy in chronic GvHD (cGvHD) and acute GvHD (aGvHD) and the appropriate point of time for skin biopsy. Eighty-eight per cent agreed that the skin biopsy is generally indicated in patients with suspected cGvHD lacking diagnostic features. In contrast, with suspected aGvHD, only 62% of respondents felt that skin biopsy was necessary even if GvHD had not been confirmed in another organ. Although restricted due to the fact that immunosuppression is often applied in an emergency setting most centres supported skin biopsies before initiation of topical or systemic immunosuppression. The majority of pathologists agreed that in non-sclerotic GvHD a punch biopsy is adequate, whereas in sclerotic GvHD a scalpel biopsy is preferred. CONCLUSION: While a consensus on the need for biopsies in cGvHD was reached the value of skin biopsies in aGvHD and subsequent biopsies during therapy requires further evaluation.