Infantile Fibrosarcoma and Other Spindle Cell Neoplasms of Infancy. A Review of Morphologically Overlapping yet Molecularly Distinctive Entities

Rhabdomyosarcoma or Fibrosarcoma? A Case of Large Ulcerated and Necrotic Lesion on the Forearm of a Newborn

“…6,7 The main prognostic factors are tumor size, surgical margin status, and presence of metastasis at diagnosis. [6][7][8] In this case, the patient had a large tumor with bone destruction and bleeding that required amputation of the left upper limb. The histopathology confirmed the diagnosis of low-grade fibrosarcoma with positive immunostaining for vimentin.…”

“…[5][6][7] The diagnosis of infantile fibrosarcoma usually depends on molecular testing, which can detect the specific gene fusion or rearrangement that is characteristic of this tumor, such as ETV6-NTRK3, LMNA-NTRK1, or TPR-NTRK1, 1,8 However, in the absence of molecular testing (which was not available in Syria due to the economic and military crisis), the diagnosis relies on the histology and immunohistochemistry of the biopsy specimen, which shows spindle-cell neoplasm with variable collagen production and mitotic activity. 6,8 Immunohistochemistry may help to differentiate infantile fibrosarcoma from other spindle-cell tumors by showing positive staining for vimentin and negative staining for S-100, desmin, smooth muscle actin and CD34. 6,8 In this case, the imaging studies and biopsy results were essential for the accurate diagnosis of fibrosarcoma, which showed spindle-cell neoplasm with variable collagen production and mitotic activity.…”

“…6,8 Immunohistochemistry may help to differentiate infantile fibrosarcoma from other spindle-cell tumors by showing positive staining for vimentin and negative staining for S-100, desmin, smooth muscle actin and CD34. 6,8 In this case, the imaging studies and biopsy results were essential for the accurate diagnosis of fibrosarcoma, which showed spindle-cell neoplasm with variable collagen production and mitotic activity. The tumor cells were positive for vimentin and negative for S-100, desmin, smooth muscle actin, and CD34.…”

“…6 In such cases, chemotherapy and/or radiotherapy may be used as neoadjuvant or adjuvant modalities to reduce the tumor size, facilitate surgery, or prevent metastasis. 6,8 Chemotherapy regimens usually include vincristine, actinomycin D, and cyclophosphamide (VAC) or vincristine, dactinomycin, and ifosfamide (VAI). 5,6 While radiotherapy may be indicated for unrespectable tumors, positive surgical margins, or metastatic disease.…”

“…5,6 While radiotherapy may be indicated for unrespectable tumors, positive surgical margins, or metastatic disease. 6,8 In this case, the patient underwent a transhumeral amputation due to the extent of the tumor and the involvement of the vascular and neurological bundles of the ulna and radius.…”