Dendritic myxofibrolipoma: often misdiagnosed as sarcoma

Dendritic fibromyxolipoma with intramuscular involvement: A case mimicking slow flow vascular malformation on imaging

Dendritic fibromyxolipoma (DFML) is a benign, very rare, and slow-growing soft tissue tumor commonly involving the muscular fascia of the foot, calf, shoulders, back, or head and neck muscles. Many authors consider dendritic fibromyxolipoma a variant of spindle cell lipoma composed of a plexiform vascular pattern, dendritic cytoplasmic processes, and keloidal collagen. Only a few cases have been reported in the shoulder region, and the presented case represents the second case in English literature whose histopathology showed intramuscular involvement. Recognition of such an entity is essential because it is considered a scarce type of benign tumor that can be mistaken for other aggressive neoplasms of myxoid pathology. We present a case of a dendritic fibromyxolipoma around the right shoulder with intramuscular involvement to the superficial fibers of the right trapezius muscle.

Dendritic fibromyxolipoma: A case report

Dendritic fibromyxolipoma (DFML) is a rare variant of spindle cell lipoma. It is characterized by extensive myxoid change and the presence of stellate cells with dendritic processes. The present study reports three cases of DFML that arose from the limbs and thoracic cavity. Pathologically, the tumor was composed of mature adipocytes admixing with patch spindle cells in a myxoid stroma. The cell atypia was not apparent and mitotic figures were rare. Immunohistochemistry revealed that the spindle cells were strongly positive for CD34. The three patients demonstrated no significant issues during a two-year's follow-up without evidence of recurrence and metastasis. The current study additionally reviewed all reported DFML cases in the PubMed database and Chinese journals.

Dendritic fibromyxolipoma of the parotid gland: a case report and review of the literature

Dendritic fibromyxolipoma, a rare subtype of lipoma, mainly occurs in the neck, back, and chest wall. Here, we describe the first reported case located in the parotid gland. It happened in a 24-year-old woman with a well-demarcated painless mass. Pathologically, the tumor was characterized by small spindle and stellate cells, an unequal number of mature fat cells, plentiful myxoid stroma, and collagenous fiber bundles. Immunochemistry demonstrated that the tumor cells were positive for vimentin, CD34, Bcl-2, and desmin, but not for keratin, EMA, SMA, or S-100. The tumor was successfully removed without complications. This report will bring to the attention of clinicians the clinical features and differential diagnosis of this unusual tumor.

[Dendritic infraclavicular fibromyxolipoma: At the boundary between spindle cell lipoma and solitary fibrous tumour]

Dendritic fibromyxolipoma (DFML) is a rare soft tissue tumor recently described with only 27 cases reported in the literature. None of them have shown recurrence or metastasis after excision. Histologically it is composed of small stellate or spindle cells in a myxoid stroma with abundant collagen bundles mixed with mature adipose tissue. The proliferating cells typically show immunoexpression positive for CD34 and bcl-2. A cytogenetic analysis reveals deletion involving 13q14.3 region. We describe the first reported case to date located in the infraclavicular region. A 69 year old male with a painless mass well circumscribed and 5cm in size of several years of evolution, that after excision (2 years ago) he has not shown signs of recurrence or metastasis. This study reflects the clinicopathological features, differential diagnosis and a review of the literature of the DFML.

Dendritic Fibromyxolipoma of the Pyriform Sinus: A Case Report and Review of the Literature

Dendritic fibromyxolipoma is a rare and distinctive soft tissue neoplasm that is considered by many authors as a variant of spindle cell lipoma and characterized by the presence of dendritic cytoplasmic processes, plexiform vascular pattern, and keloidal collagen. It has never been reported in the larynx and hypopharynx. Its rarity and the potential to mistake it as a more clinically aggressive myxoid soft tissue neoplasm highlight the importance of its recognition. Here, a case of a dendritic fibromyxolipoma of the pyriform sinus in a 38-year-old male who presented with dysphagia, change of voice, and stridor is reported. A review of the literature, including histopathologic features and differential diagnosis, is also included.

Dendritic fibromyxolipoma in the latissimus dorsi: a case report and review of the literature

Dendritic fibromyxolipoma is an uncommon benign soft tissue tumor. Here, we report a case in a 53-year-old man presenting a painless mass located deep in the latissimus dorsi of the right back. Microscopically, the tumor was mainly consisted of small spindle and stellate cells, abundant myxoid stroma, collagen bundles and mature adipose tissue. Immunohistochemical study showed the spindle and stellate cells were positive for CD34, Bcl-2 and Vimentim, but not for Keratin, EMA, SMA and Desmin. To date, one year after operation, the patient is well without evidence of recurrence or metastasis. The implication of this report is to provide insights into further understanding of this rare tumor with review of the literature.

Intramuscular dendritic fibromyxolipoma in a 24-year-old male: A case report and review of the literature

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. Fluorescence in situ hybridization 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.

Dendritic fibromyxolipoma on the nasal tip in an old patient

Dendritic myxofibrolipoma is a newly described benign soft tissue tumor that could be easily mistaken for sarcoma. It develops primarily in the subcutis or muscular fascia of the head and neck, shoulders, etc. Histologically, the tumor is characterized by an admixture of mature adipose tissue, spindle and stellate cells, and abundant myxoid stroma with prominent collagenization. These neoplasms typically show positive immunoreactivity for CD-34, vimentin and Bcl-2. Herein, we described a rare case presenting with a papule on the nasal tip in a 69-year old patient. Histopathology and immunohistochemical staining confirmed the diagnosis. In short, it brings the attention of clinicians to the importance of proper identification and characterization of this tumor.

Dendritic fibromyxolipoma in the right inguinal and perineum regions: a case report and review of the literature

Abstract

A 32-year-old woman presented with a slow-growing, painless, subcutaneous lesion in the right inguinal and perineum regions. The mass was 24.0 cm × 10.5 cm × 5.0 cm in size, well circumscribed, mobile, and rubbery. Microscopically, the resected mass was mainly composed by a proliferation of small spindle or stellate cells, variably admixed with mature adipose tissue, embedded within an abundant myxoid and collagenized stroma. Immunohistochemically, the spindle and stellate cells were strongly positive for vimentin, CD34, and bcl-2 antibodies but not for smooth muscle actin and desmin. The tumor was diagnosed as dendritic fibromyxolipoma based on the typical findings of histology and immunohistochemistry. Clinical follow-up of 9 months after surgery revealed no evidence of recurrence. We report the first case of dendritic fibromyxolipoma in the right inguinal and perineum regions and discuss the different diagnosis.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1313680868103019.