Cytology of soft tissue tumors: cytological classification of soft tissue tumors

Manoj Kumar Choudhuri (first name)

Department of Pathology, B. S Medical College, Bankoula, West Bengal.

Department of Pathology, Bankoula Medical College, West Bengal.

According to the existing knowledge, the classification of any disease will change from time to time, such as soft tissue tumors. The WHO classification of soft tissue tumors was first published in 1969, and was revised twice in 1994 and 2002.

According to the existing knowledge, the classification of "changes in diseases" has been changing with time. The classification of soft tissue tumors is such an example. The classification of soft tissue tumors established by the World Health Organization (WHO) was first published in 1969, and was revised in 1994 and 2002 respectively.

The following are some major changes in the latest classification: [1], [2]

The following are some major changes in the "latest classification".

Fibroblastoma/so-called fibrous histiocytoma: The most remarkable change in this group is that malignant fibrous histiocytoma has lost its luster, and myxoid fibrous histiocytoma, which is considered as "undifferentiated pleomorphic sarcoma", has been replaced by myxofibrosarcoma, which is the most common soft tissue sarcoma in the elderly.

Fibrohistiocytoma/so-called fibrous tumor;

The most remarkable change in this group is that histiocytoma composed of malignant fibers is not as remarkable as it used to be, and now it has been downgraded to "undifferentiated pleomorphic sarcoma". Myxoid fibrous histiocytoma has been replaced by myxofibrosarcoma, which is the most common soft tissue sarcoma in the elderly.

Smooth muscle tumor and skeletal muscle tumor: There was no significant change in this group.

Smooth muscle tumor and skeletal muscle tumor: There was no significant change in this group.

Adipocyte tumor: well-differentiated liposarcoma has no malignant potential, so "atypical lipoma" is the preferred term when the tumor occurs in limbs and other operable parts. However, the term "well-differentiated liposarcoma" refers specifically to tumors that occur in retroperitoneum and mediastinum. Even without dedifferentiation, incomplete resection will lead to local recurrence. Myolipoma and chondroid lipoma are two new entities in recent classification.

Lipocytoma: It is a well-differentiated liposarcoma with no malignant potential. Therefore, the name of atypical lipoma is adopted, because tumors occur in limbs of the body, such as limbs and other places suitable for surgery. However, the name well-differentiated liposarcoma is used for tumors that occur in the posterior abdominal cavity and mediastinum. Even without "dedifferentiation", incomplete resection will lead to local recurrence. Myolipoma and chondroid lipoma are two newly added categories.

Pericellular tumors: Some tumors previously classified as hemangiopericytomas are indistinguishable from "solitary fibrous tumors". However, hemangiopericytoma of nasal cavity and paranasal sinuses seems to be a real pericellular lesion. A large number of pericytoma/perivascular tumors were renamed as "perimyocytoma".

Pericytoma: Some tumors previously classified as perivascular cell tumors are not obviously different from solitary fibrous tumors. However, pericytoma of nasal cavity and paranasal sinuses seems to be really destroyed by pericytes.

This large group of pericytes has been renamed as perimyocytoma.

Vascular tumor: spindle cell hemangioendothelioma was renamed "spindle cell hemangioma"

Vascular tumor: spindle cell hemangioendothelioma was renamed spindle cell hemangioma.

We all know that the diagnosis by fine needle aspiration depends on pattern recognition. Therefore, the cytological classification of soft tissue tumors is based on the main patterns. In recent years, immunocytochemistry has been increasingly used for further classification of lesions.

Diagnosis by fine needle aspiration depends on pattern recognition. Therefore, cytological classification of soft tissue tumors is established according to the "main mode". Recently, immunocytochemistry has been gradually applied to further organ damage.

Soft tissue tumors are divided into five groups according to their cytological results [3]:

According to cytological results, soft tissue tumors are divided into five groups:

Polymorphism: the aspirate is rich in cells, and the size and shape of cells have obvious changes. The polymorphism of the nucleus is remarkable, and some tumor cells show large nucleoli; Strange tumor giant cells can be detected. Liposarcoma multiforme, undifferentiated sarcoma multiforme and rhabdomyosarcoma multiforme belong to this category.

Polymorphic morphology: the aspirate is completely cells, and the size and shape of cells vary greatly. Nuclear pleomorphism is prominent, and some tumor cells are large nuclei; Giant cells of weird tumors can be detected. Liposarcoma pleomorphic, undifferentiated pleomorphic sarcoma and rhabdomyosarcoma pleomorphic all belong to this category.

Spindle cell pattern: Spindle cells shed in bundles. Typical spindle cells have spindle or oval nuclei; The cytoplasm is conical, unipolar or bipolar; The number of mitosis is variable. Fibrosarcoma and leiomyosarcoma present typical spindle cell patterns.

Morphology of spindle cells: spindle cells fade into clusters. The nucleus of a typical spindle cell is spindle-shaped or oval. One end of cytoplasm is wide and the other end is thin, unipolar or bipolar; The appearance of mitosis is changeable. Fibrosarcoma and hysteromyoma have typical spindle cell morphology.