Clonal analysis of palmar fibromatosis: a study whether palmar fibromatosis is a real tumor.
BACKGROUND
Palmar fibromatosis that arises in the palmar soft tissue is characterized by infiltrative growth with a tendency toward local recurrence but does not metastasize. This study investigated the clonality of this process in twelve female patients, each with a single lesion, by examining the pattern of X-chromosome inactivation.


METHODS
Hematoxylin and eosin stained sections of formalin-fixed, paraffin-embedded tissues were microdissected by laser capture microdissection to obtain the proliferative spindle cells. Tumor cells were isolated from the sections of rectum adenocarcinoma, and used for positive control. The genomic DNAs was extracted with phenol-chloroform, digested with a methylation-sensitive restriction endonuclease HpaII, and amplified by polymerase chain reaction (PCR), using primers targeted to a highly polymorphic short tandem repeat (STR) of the human androgen receptor gene (HUMARA).


RESULTS
Among the twelve samples, three samples failed amplification, one sample showed homozygosity which was not suitable for further analysis, eight samples were successfully amplified, and showed a random X chromosome inactivation pattern, suggesting polyclonality of these lesions.


CONCLUSIONS
The current findings suggest that palmar fibromatosis is a reactive proliferation rather than a clonal neoplasm.
Wang
Lei
L
Department of Pathology, Fudan University Shanghai Medical College, Yixueyuan Road 138, Shanghai, China. wanglei56713@yahoo.com.cn
Zhu
Hongguang
H