Almost 10% of breast and ovarian cancers are familial, and the majority are linked to BRCA1 and BRCA2 germline mutations. Despite uncertainty about the management of female gene carriers, consensus guidelines have been established to assist practitioners and consultees in making health care decisions.

Consensus was recently reached in the Netherlands regarding the clinical management of dysplastic naevi and the definitions in clinical and pathological diagnostics. The term 'dysplastic' is reserved for histological diagnostics; the term preferred for clinical use is 'clinically atypical naevus'. A naevus is defined as clinically atypical if it meets three of the following five criteria: > or = 5 mm in diameter, vaguely bordered, asymmetrically shaped, irregularly pigmented and a red hue (erythema). Presence of clinically atypical naevi is a main risk factor for melanoma. Dysplastic naevus syndrome (DNS) is present if a patient has a melanoma and one or several clinically atypical naevi. The diagnosis of 'familial DNS' (familial atypical multiple mole-melanoma syndrome, abbreviation FAMMM syndrome) is made if at least two close relatives (including the patient) are known with a melanoma with or without atypical naevi, while one or several (other) relatives have atypical naevi. The risk of melanoma in a gene carrier of familial DNS is close to 100%, while multiple melanomas develop in 30% of the gene carriers. No DNA diagnostics is yet possible in most DNS/FAMMM families, because of the involvement of genes yet unknown. Accordingly, at present it is still too early for DNA diagnostics. Currently, therefore, the diagnosis is based only on anamnestic, clinical and histological grounds.

To provide recommendations for cancer surveillance and risk reduction for individuals carrying mutations in the BRCA1 or BRCA2 genes.

To provide recommendations for cancer surveillance and risk reduction for individuals carrying mutations associated with hereditary nonpolyposis colon cancer (HNPCC).

Cytology, cytochemistry, immunophenotyping and cytogenetic analysis have specific roles in the diagnosis and management of various haematological neoplasms. Careful examination of Romanowsky-stained films of blood and bone marrow is fundamental in all haematological diagnosis and, when considered together with clinical and haematological features, indicates which of the more specialized techniques are most likely to be useful. The major role of cytochemistry is in the diagnosis of acute myeloid leukaemia and the myelodysplastic syndromes. The major role of immunophenotyping is in the diagnosis of the chronic lymphoproliferative disorders and of acute leukaemia which is not obviously myeloid. Cytogenetic analysis has a role in confirming the diagnosis of chronic granulocytic leukaemia and gives important supplementary information in the acute leukaemias and the myelodysplastic syndromes.

The primary objective was to determine clinical practice guidelines for the use of tumor marker tests in the prevention, screening, treatment, and surveillance of breast and colorectal cancers. These guidelines are intended for use in the care of patients outside of clinical trials.