title: Intramuscular dendritic fibromyxolipoma in a 24-year-old male: A case report and review of the literature.
abstract: Dendritic fibromyxolipoma (DFML) is an uncommon, benign soft tumor that usually arises in the subcutis. To date, ~24 cases of DFML have been reported in the literature and only one of these has been in the muscle. The present study reports the case of a 24-year-old male with a slow-growing, painless mass located deep in the triceps brachii in the left shoulder region. The mass was 14.0×8.5×8.0 cm in size, with well-circumscribed margins. Microscopically, the resected mass was characterized by a proliferation of small spindle or stellate cells, prominent abundant myxoid stroma with ropey collagen bundles and admixed mature adipose tissue. Further immunohistochemical staining indicated that the spindle and stellate cells were reactive with cluster of differentiation 34, vimentin and B-cell lymphoma-2, but not with smooth muscle actin and desmin. Fluorescencein situhybridization showed that the tumor cells did not have the DDIT3 alteration or amplification of MDM2. The tumor was confirmed to be a DFML due to the typical histological, immunophenotypic and genetic findings. To date, subsequent to 4 years of clinical follow-up, there is no sign of recurrence or metastasis. The present study reports a case of DFML in the youngest known patient, and is the second reported case of an intramuscular DFML occurring in the triceps brachii in the left shoulder region. The study discusses the clinicopathological features and the differential diagnosis of DFML, with a review of the literature.
authors.affiliation: Department of Pathology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China.
authors.forename: Xia
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Orthopaedics, Wuhan Puai's Hospital, Wuhan, Hubei 430032, P.R. China.
authors.forename: Wen
authors.initials: W
authors.lastname: Xiong
authors.affiliation: Department of Pathology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China.
authors.forename: Liduan
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yu
keywords: dendritic fibromyxolipoma; intramuscular; myxoid spindle cell lipoma; solitary fibrous tumor