SEER Inquiry System - Search

Code the Primary Site field as follows:

1. C44.9 [Skin, NOS] as the default value when lesions develop simultaneously in skin and non-skin areas.

2. C07.9 [Parotid gland]

3. C44.9 [Skin, NOS] as the default value when there is no mention of lesions in the skin or other primary site.

Edward Klatt states in Practical AIDS Pathology, "...Visceral Kaposi (involving one or more internal organ sites) is also present in three-fourths of cases, but may not be diagnosed prior to autopsy. Visceral involvement frequently includes the lung, lymph nodes and gastro-intestinal tract."

NTRK-rearranged spindle cell neoplasm is a newly identified variant of sarcoma; however, WHO has not yet proposed a specific ICD-O code for this rare neoplasm. Code to spindle cell sarcoma (8801/3).

WHO defines NTRK-rearranged spindle cell neoplasm as an emerging group of molecularly defined rare soft tissue tumors that span a wide group of morphologies and histological grades, and are most often characterized by a spindle cell phenotype among other characteristics.

Assign code 8825/3. Apply the ICD-O-3 Matrix Concept, Rule F, page 29 of the hardcover ICD-O-3. The WHO Classification of Soft tissue and Bone, page 85, lists low grade myofibroblastic sarcoma, also called myofibrosarcoma, 8825/3.

For tumors diagnosed prior to 2007:

Code histology as 9260/3, Ewing sarcoma. Ewing sarcoma is a specific histology on the continuum of primitive neuroectodermal tumors. Code Ewing sarcoma as it is more specific than PNET, NOS.

For tumors diagnosed 2007 or later, refer to the MP/H rules. If there are still questions about how this type of tumor should be coded, submit a new question to SINQ and include the difficulties you are encountering in applying the MP/H rules.

For tumors diagnosed prior to 2007:

The ICD-O-3 histology code is 8811/3 [Fibromyxosarcoma] according to the WHO Classification of Tumours of Soft Tissue and Bone. WHO defines myxoinflammatory fibroblastic sarcoma (MIFS) as "a unique low grade sarcoma with myxoid stroma, inflammatory infiltrate and virocyte-like cells that predominantly involves the hands and feet."

For tumors diagnosed 2007 or later, refer to the MP/H rules. If there are still questions about how this type of tumor should be coded, submit a new question to SINQ and include the difficulties you are encountering in applying the MP/H rules.

Code as undifferentiated round cell sarcoma (8803/3).

The CIC rearrangement exists as a distinct molecular and clinical subset of small round cell tumors, and though similar, is felt to be a distinct entity from Ewing sarcoma. According to WHO Classification of Soft Tissues and Bone, 4th Edition, CID-DUX4 is a recurrent gene fusion associated with pediatric round cell undifferentiated soft tissue sarcoma (USTS). Although the genes involved in the fusion are different from those in Ewing sarcoma, the CIC-DUX4 protein has been shown to upregulate genes of the ETS family of genes thus providing a molecular link between Ewing sarcoma and round cell USTS. In contrast, there are strong arguments to suggest that Ewing-like sarcomas represent a separate and distinct entity.

Apply 2007 MP/H rule H6 and assign the numerically higher ICD-O-3 code that reflects PNET (9364/3).

According to the WHO Tumors of Soft Tissue and Bone, though Ewing sarcoma ICD-O-3 code is 9260/3, Ewing sarcoma with a higher degree of neuroectodermal differentiation present is classically termed peripheral neuroectodermal tumors (PNET).  WHO does not offer guidance how to classify tumors stated to be Ewing sarcoma PNET.

Histology code 9364/3 is assigned for a Ewing/PNET that arises outside of the brain/CNS. Peripheral neuroectodermal tumor (PNET) and peripheral primitive neuroectodermal tumor (PPNET) are Ewing family tumors.

Histology code 9473/3 (PNET, primitive neuroectodermal tumor, central primitive neuroectodermal tumor, or supratentorial PNET) is only used for tumors arising inside the brain/CNS.

Assign 8802/34 to pleomorphic cell sarcoma/undifferentiated pleomorphic sarcoma. Pleomorphic is more important than undifferentiated when choosing the histology code in this case. Undifferentiated can be captured in the grade code.                           

Code the primary site to pulmonary artery, C493. According to the WHO classification of tumors, intimal sarcomas are malignant mesenchymal tumors arising in large blood vessels. They show mostly intraluminal growth with obstruction of the vessel. They may occur in the pulmonary vessels or, less often, in the aorta.