[4][5] Based primarily on histopathologic (i.e. microscopic appearance of specially prepared tissue) analyses, lipofibromatosis was initially regarded as either a type of, or very similar to, aponeurotic fibroma (also termed calcifying aponeurotic fibroma),[6] fibrous hamartoma of infancy,[7] EWSRI-SMAD3-rearranged fibroblastic tumor (also termed EWSR1-SMAD3-positive fibroblastic tumor),[8] or infantile digital fibromatosis.
[9] Lipofibromatosis-like neural tumor was defined in 2016 as a disorder which initial studies regarded to be a variant of lipofibromatosis.
[10][11] However, more recent studies have emphasized critical differences in the clinical presentations and gene abnormalities between these two tumors.
[1] This fat tissue is composed of adipocyte-like cells, some of which are distinctly abnormal[8] in that they contain one relative large vacuole, resemble lipoblasts (precursors to mature adipocytes),[8] and show considerable variations in their appearances.
[8] A recent study found various fusion genes in the spindle-shaped cells of LPF tumors using fluorescence in situ hybridization, RNA sequencing, and real-time polymerase chain reaction analyses of formalin-fixed, paraffin-embedded tumor tissue.
[7][11] The diagnosis of LPF depends on its clinical presentation almost exclusively in newborn and young children and, most importantly, its histopathology as determined on biopsied intact tissue or fine-needle aspiration to obtain a sampling of the tumor's cells.
[2] For diffusely infiltrative LPF tumors, partial resection (i.e. debulking) with the lowest potential postoperative morbidity has been employed.
[1][2][18] Incomplete surgical removal of the tumor, male sex, presence at birth, occurrence on the hands and feet, and a high mitotic index (i.e. rate of cell proliferation on microscopic tissue examination) are predisposing factors for recurrence.