In addition to Wilms tumor and hepatoblastoma, children with BWS have been shown in individual case reports to develop ganglioneuroma, adrenocortical carcinoma, acute lymphoid leukemia, liver sarcoma, thyroid carcinoma, melanoma, rhabdomyosarcoma, and mesoblastic nephroma.Wilms tumor, hepatoblastoma, and mesoblastic nephroma can usually be cured if diagnosed early. Early diagnosis allows physicians to treat the cancer when it is at an early stage. In addition, there is less toxic treatment. Given the importance of early diagnosis, all children with BWS should receive cancer screening.An abdominal ultrasound every 3 months until at least eight years of age is recommended and a blood test to measure alpha-fetoprotein (AFP) every 6 weeks until at least four years of age. Families and physicians should determine screening schedules for specific patients, especially the age at which to discontinue screening, based upon their own evaluation of the risk-benefit ratio. Genetics
Most (>85%) cases of BWS are sporadic, meaning that, typically, no one else in that family has BWS, and parents of an affected child are not at increased risk of having other children with BWS. However, some (<15%) cases of BWS are familial, meaning that a close relative may also have BWS, and parents of an affected child may be at increased risk of having other children with BWS.
Café au lait spots, or café au lait macules, are flat, hyperpigmented birthmarks. The name café au lait is French for "coffee with milk" and refers to their light-brown color. Café au lait lesions with rough borders ("coast of Maine") may be seen in McCune-Albright syndrome. In contrast, Café au lait lesions of neurofibromatosis have smooth borders ("coast of California").They are caused by a collection of pigment-producing melanocytes in the epidermis of the skin.These spots are typically permanent and may grow or increase in number over time.Café au lait spots are often harmless but may be associated with syndromes such as neurofibromatosis type 1 and McCune–Albright syndrome. Cause
Café au lait spots can arise from diverse and unrelated causes:
Ataxia–telangiectasia
Basal cell nevus syndrome
Benign congenital skin lesion
Bloom syndrome
Chédiak–Higashi syndrome
Congenital melanocytic naevus
Fanconi anemia
Gaucher disease
Hunter syndrome
Jaffe–Campanacci syndrome
Legius syndrome
Maffucci syndrome
They can be caused by vitiligo in the rare McCune–Albright syndrome. Multiple mucosal neuroma syndrome
Having six or more café au lait spots greater than 5 mm in diameter before puberty, or greater than 15 mm in diameter after puberty, is a diagnostic feature of neurofibromatosis type I (NF-1), but other features are required to diagnose NF-1. Familial multiple cafe-au-lait spots have been observed without an NF-1 diagnosis. Noonan syndrome
Silver–Russell syndrome
Tuberous sclerosis
Watson syndrome
Wiskott–Aldrich syndrome

Diagnosis
Diagnosis is visual with measurement of spot size. The number of spots can have clinical significance for diagnosis of associated disorders such as Neurofibromatosis type I.