Cytogenetics of neuroﬁbromas: two case reports and literature review
Kenian Liu, Patricia DeAngelo, Kathleen Mahmet, Penny Phytides,
Lisa Osborne, Beth A. Pletcher
Institute of Genomic Medicine, University of Medicine & Dentistry of New Jersey, 185 South Orange Avenue, MSB F665, Newark, NJ 07101
Received 7 April 2009; accepted 24 July 2009
Only a few karyotypes of neuroﬁbromas have been documented in the literature. In this report, we
describe two new cases in which conventional cytogenetics demonstrated the presence of abnormal
clones. Combining karyotypes of the nine previously reported cases, we found that the most
frequent structural rearrangements involved chromosome 9p. Including the two cases reported here,
5/11 cases involved 9p, and four of these involved the 9p21~p22 region. Ó 2010 Elsevier Inc. All
Neuroﬁbromas are benign, heterogeneous peripheral
nerve sheath tumors that occur in association with von
Recklinghausen disease [neuroﬁbromatosis type 1 (NF1)],
but may also occur sporadically. These tumors are generally
classiﬁed into ﬁve types: localized cutaneous neuroﬁ-
bromas, diffuse cutaneous neuroﬁbromas, localized intra-
neural neuroﬁbromas, plexiform neuroﬁbromas, and
massive soft-tissue neuroﬁbromas [1,2]. Localized cuta-
neous, plexiform, and massive soft-tissue neuroﬁbromas
are the most speciﬁc for NF1 [2,3]. Neuroﬁbromas can be
found anywhere within the central or peripheral nervous
system, especially in the neck, thorax, cranium, retroperito-
neum, and ﬂexor surfaces of the extremities.
The role of cytogenetics in the clinical diagnosis of
oncologic and hematologic malignancies has generated
more and more attention throughout the past years [4,5].
Characteristic chromosome aberrations in certain tumors
not only can clarify the histologic diagnosis, but also may
provide important prognostic information about these
tumors. In addition, the ﬁndings of characteristic, some-
times pathognomonic, chromosome aberrations in several
types of soft-tissue tumors have added to our understanding
of the mechanisms behind the genesis of these tumors [4,5].
However, for many soft-tissue tumors, including neuroﬁ-
bromas, the number of analyzed cases is still very low.
To the best of our knowledge, only nine neuroﬁbroma cases
have been reported (Table 1). Here, we report on two cases
with a pathologic diagnosis of neuroﬁbroma as well as
abnormalities on cytogenetic analysis.
2. Materials and methods
2.1. Case report
2.1.1. Case 1
A 17-year-old female had a left leg mass excised. The
mass size was 1.6 Â 0.8 Â 0.7 cm. Immunohistochemical
staining showed was positive for S-100 protein. Final histo-
logic diagnosis was reported as neuroﬁbroma. The patient
was diagnosed with neuroﬁbromatosis type 1 in early
childhood. Clinical features were consistent with a deletion
form of NF1; she developed multiple malignant peripheral
never sheath tumors in addition to benign neuroﬁbromas.
2.1.2. Case 2
A 24-year-old male presented with a history of a ﬁrm
left posterior thigh mass. At surgery, the mass was resected
with normal-appearing surrounding tissues. Pathological
examination showed that the excised mass had clear
margins without tumor tissue; the mass measured 6.8 Â
5.2 Â 5.0 cm. The histologic diagnosis was reported as
neuroﬁbroma. The patient has had several benign neuroﬁ-
bromas without other clinical features of NF1, but family
history is signiﬁcant for a neuroﬁbroma and two malignant
peripheral nerve sheath tumors in his mother.
A fragment of fresh tumor was sent for cytogenetic
analysis. The tumor tissue was minced and dissociated with
* Corresponding author. Tel.: (973) 972-3300.
E-mail address: email@example.com (B.A. Pletcher).
0165-4608/10/$ e see front matter Ó 2010 Elsevier Inc. All rights reserved.
Cancer Genetics and Cytogenetics 196 (2010) 93e95