Spindle cell neoplasm

A spindle cell neoplasm is an abnormal growth (a tumour) made up of spindle-shaped cells. These cells are longer than they are wide, similar to the shape of a grain of rice or a stretched oval. The term spindle cell neoplasm is broad because it includes many different kinds of growths, some benign (non-cancerous) and others malignant (cancerous). When a pathologist uses this general term, it often means there isn’t enough information to provide a more specific diagnosis, and additional tests may be needed to identify the exact type.

Your doctors may use the general term “spindle cell neoplasm” after an initial tissue sample is examined, especially if the exact type of tumour isn’t clear yet. This term helps your doctors plan your care while waiting for more information.

Are all spindle cell neoplasms cancerous?

No, not all spindle cell neoplasms are cancerous. Many types are benign (non-cancerous) and do not spread to other body parts. To determine whether a spindle cell neoplasm is benign or malignant (cancerous), a pathologist examines the tissue carefully under a microscope and may order special tests, such as immunohistochemistry. Immunohistochemistry uses special markers to identify the type of cells involved, which can help clarify the diagnosis. Other tests, like fluorescence in situ hybridization (FISH) or molecular tests like next-generation sequencing (NGS), might also be done.

Examples of benign (non-cancerous) spindle cell neoplasms

Benign spindle cell neoplasms include tumours like schwannoma, neurofibroma, solitary fibrous tumour, spindle cell lipoma, leiomyoma, and fibromatosis. These tumours usually don’t spread to other body parts, but some types (like fibromatosis) can grow back even after being surgically removed. Your doctor may recommend routine follow-up visits to ensure the tumour doesn’t return.

Examples of malignant (cancerous) spindle cell neoplasms

There are also many types of malignant spindle cell neoplasms, most of which are called sarcomas. Sarcomas are cancers that develop from connective tissue like fat, muscle, nerves, or blood vessels and can spread to other body parts. Common examples include malignant peripheral nerve sheath tumour, dermatofibrosarcoma protuberans, liposarcoma, osteosarcoma, leiomyosarcoma, angiosarcoma, synovial sarcoma, and undifferentiated pleomorphic sarcoma. Some other cancers, such as squamous cell carcinoma or melanoma, can sometimes look spindle-shaped and might initially be called spindle cell neoplasms until further tests clarify the exact type.