Hemosiderotic fibrolipomatous tumor (HFLT) is a slow-growing subcutaneous mass composed of hemosiderin pigment, spindle cells, and mature adipocytes. HFLTs usually present in the fifth to sixth decades of life, with a median age of onset of 50 years, and is more frequent in females, at a ratio of 2.8:1. Fewer than 100 cases have been reported.
HFLT appears most commonly as a variably circumscribed, green-blue to brown plaque on the dorsal aspect of the foot or ankle. More rarely, HFLTs have been reported on the hands, wrists, forearms, legs, and face. Plaque size ranges from 0.1-19 cm in reported cases (average size around 7.7 cm). The lesions may be soft, mobile, and tender. To date, only 1 case has been reported of HFLT arising within bone.
HFLT was originally thought to arise as a reactive inflammatory process as, rarely, patients with HFLT have reported a history of trauma and/or vasculopathy at the site of the tumor. Therefore, it has been postulated that repeated minor blood vessel damage in tight dorsal compartments of highly mobile joints may be a factor in the development of HFLT.
However, 17 reported cases have shown chromosomal translocation of (1;10)(p22;q24) and/or rearrangements in TGFBR3/MGEA5 with cytogenetic analysis; therefore, a neoplastic origin is also posited. Cases of HFLT have also been reported to progress to a hybrid of HFLT and myxoinflammatory fibroblastic sarcoma (HFLT-MIFS), and these cases also display this chromosomal rearrangement.
HFLT displays a relatively high recurrence rate after surgical resection of 30%-50%. A single case of transformation into a low-grade unclassified pleomorphic sarcoma has been reported.
Hemosiderotic fibrolipomatous tumor
Alerts and Notices
Synopsis
Codes
ICD10CM:
D17.0 – Benign lipomatous neoplasm of skin and subcutaneous tissue of head, face and neck
D17.20 – Benign lipomatous neoplasm of skin and subcutaneous tissue of unspecified limb
SNOMEDCT:
254830006 – Benign lipomatous tumor
D17.0 – Benign lipomatous neoplasm of skin and subcutaneous tissue of head, face and neck
D17.20 – Benign lipomatous neoplasm of skin and subcutaneous tissue of unspecified limb
SNOMEDCT:
254830006 – Benign lipomatous tumor
Look For
Subscription Required
Diagnostic Pearls
Subscription Required
Differential Diagnosis & Pitfalls
- Hematoma
- Pigmented epithelioid melanocytoma – A melanoma subtype appearing as heavily pigmented lesions in young patients that is negative for CD34 spindle cells with positive staining for S100, SOX10, and HMB45.
- Pigmented dermatofibrosarcoma protuberans (Bednar tumor) – A variant of dermatofibrosarcoma protuberans (DFSP) that stains positive for CD34 spindle cells and Melan-A.
- Angiomatoid fibrous histiocytoma – Multinodular lesions with hemosiderin deposits and granulomatous epithelioid to occasionally spindled cells due to EWSR1 gene rearrangement.
- Spindle cell lipoma – CD34+ benign lipomatous tumor more commonly occurring on the neck, upper back, and shoulders in males aged 40-70 years.
- Spindle cell hemangioma – A benign vascular lesion occurring in the distal extremities that shows spindle cells, cavernous spaces, and epithelial vacuolated cells on histology.
- Epithelioid sarcoma – A slow-growing soft tissue tumor occurring in the distal extremities that often stains positive for CD34 and characteristically lacks INI-1 expression in tumor cells.
- Lipofibromatosis / fibromatosis – A benign fibrofatty soft tissue tumor occurring in the distal extremities in the pediatric population that lacks hemosiderin and infiltrates adipose tissue.
- Atypical lipomatous tumor – Contains adipocytes of variable sizes with lipoblasts and atypical cells.
- Plexiform fibrohistiocytic tumor – A slow-growing subcutaneous mass occurring in the distal extremities of children and young adults with immunoreactivity for vimentin and CD68.
Best Tests
Subscription Required
Management Pearls
Subscription Required
Therapy
Subscription Required
References
Subscription Required
Last Reviewed:07/15/2023
Last Updated:07/25/2023
Last Updated:07/25/2023