Enchondromatosis is a term encompassing several disorders distinguished by the formation of multiple cartilaginous benign tumors, enchondromas. Ollier disease and Maffucci syndrome are the two most important forms of enchondromatosis, and symptoms, when present, include the presence of palpable bony masses in distal extremities, primarily in fingers or toes. Depending on the subtype of enchondromatosis, a number of skeletal-related symptoms may be encountered. Clinical, radiologic, and genetic studies are necessary to make the diagnosis.
Defined as a benign tumor of hyaline cartilage that arises in the metaphyseal parts of the bone, an enchondroma is mentioned as a constitutive feature of various disorders, one of them being enchondromatosis, a group of diseases characterized by the presence of multiple enchondromas together with various accompanying features     . Although more than 10 disorders have been described in the literature (the majority being non-hereditary), the two most important and most common are Ollier disease and Maffucci syndrome    :
Apart from Ollier disease and Maffucci syndrome, conditions in which multiple enchondromas develop may possess a hereditary component (genochondromatosis, in which normal stature, symmetrical lesions and possibly clavicular thickening are encountered, and metachondromatosis), spinal lesions (spondyloenchondrodysplasia) that might be accompanied by mental retardation (cheirospondyloenchondromatosis) or neonatal dwarfism (dysspondyloenchondromatosis) . It must be pointed out that malignant transformation of enchondromas can occur, particularly in Maffucci syndrome   .
Signs and symptoms of diseases that comprise enchondromatosis in their pathogenesis may not be easy to detect without a thorough diagnostic workup. Firstly, patients (or their parents) should be asked about the course of symptoms, their progression, and if similar complaints are present in either of the parents (having in mind the autosomal dominant pattern of inheritance for genochondromatosis and metachondromatosis). A meticulous physical examination is perhaps even more important, as a complete body inspection and palpation of the skeleton allows identification of multiple bony masses in a predominantly asymmetric fashion. Imaging studies, however, are the cornerstone in establishing a solid diagnosis. On plain radiography, enchondromas appear as oval or elongated radiolucent homogeneous lesions that possess a well-defined bony margin    . If X-rays reveal cortical erosion, tumor extension into soft tissues, or an irregular border, the malignant transformation should be suspected . More advanced studies, such as magnetic resonance imaging (MRI) and computed tomography (CT) are employed when inconclusive findings are obtained on radiography . Finally, a biopsy with subsequent histopathological examination might be used for confirmation of an enchondroma  .