SEER Inquiry System - Search

The ICD-O-3.2 Coding Table includes Mullerian mixed tumor as the preferred term for histology code 8950 (previously malignant mixed Mullerian tumor/MMMT). This table also includes carcinosarcoma, NOS as the preferred term for histology code 8980. Neither the ICD-O-3.2 Coding Table nor the Implementation Guidelines address the long-standing issue of coding histology for diagnoses of carcinosarcoma/malignant mixed Mullerian tumor.

These endometrial primaries are frequently diagnosed as both carcinosarcoma and MMMT. The questions regarding histology coding for carcinosarcoma and carcinosarcoma/MMMT of the endometrium date back to before the Multiple Primaries/Histology Rules, with at least three SINQ entries instructing registrars not to use code 8950/3 (MMMT) for diagnoses of MMMT. SINQ has instructed registrars that MMMT is a synonym for carcinosarcoma and these tumors should be coded to 8980 (carcinosarcoma), not to 8950 (MMMT). The most recent SINQ is partly inconsistent with the others, indicating 8950 can be used if the tumor is only described as MMMT. The other SINQ entries state carcinosarcoma should be used as it is the preferred term for MMMT. (See SINQ 20061008, 20100009, 20180071.)

The most recent SINQ (20180071) specifically indicates: According to the WHO Classification of Tumors of Female Reproductive Organs, 4th edition, MMMT (8950/3) is now a synonym for carcinosarcoma (8980/3) even though it has a separate ICD-O code. The ICD-O code for MMMT is no longer in the WHO book. However, MMMT is in the ICD-O-3.2 Coding Table and is not stated to be obsolete or a synonym. Which is correct, the clarification in the SINQ or the 2021 ICD-O-3.2 Coding Table?

For a 2021 diagnosis of carcinosarcoma/malignant mixed Mullerian tumor, how should registrars code the histology? Follow the previous SINQ entries and Rule H17 to code the histology to 8980 when the diagnosis includes both carcinosarcoma and MMMT? Do these previous SINQ entries still apply to cases diagnosed 2021 and later?

This question was prompted from preparing SEER*Educate coding exercises. We will use the answer as a reference in the rationales.

Rule H8 of the Melanoma Solid Tumor Rules states that multiple variants of melanoma in one tumor are rare and a question must be submitted to Ask a SEER Registrar (AASR) for the correct histology code. However, our facility has seen a number of these cases in 2021 and would like to track the official answer and make it available to all in this format.

How should histology be coded for the following?

1. January 2021 diagnosis of left shoulder invasive malignant melanoma, histologic type: nodular and desmoplastic types per College of American Pathologists (CAP) summary of punch biopsy.

2. May 2021 shave biopsy of left arm invasive malignant melanoma, superficial spreading and nodular variant is listed in the CAP summary.

3. June 2021 diagnosis of right cheek invasive malignant melanoma, histologic subtype: superficial spreading and nodular seen on CAP summary of shave biopsy.

Left radical nephrectomy: Tumor histologic type: Renal angiomyoadenomatous tumor (see Note). Note: The a clear cell papillary renal cell tumor and a renal angiomyoadenomatous tumor (""RAT"") (reval cell carcinoma with angioleiomyoma-like stroma). Although some authors consider RAT tumors to represent a pattern of clear cell papillary RCC we believe that this represents a dstinct entity. The combined findings ...confirm the diagnosis of renal angiomyoadenomatous (RAT) tumor. These tumors are also known as renal cell carcinoma within angioleiomyoma-like stroma. To date none of these tumors have developed metastases. Given the small number of reported cases we would consider these to have at worst a low malignant potential.

The patient was diagnosed with GE junction signet ring adenocarcinoma (8490/3) in 5/2012, treated with radiation. GE junction biopsy on 9/20/2012 showed residual signet ring carcinoma. Subsequent biopsies on 7/8/2013 showed GE junction biopsy of invasive adenocarcinoma, signet ring cell type along with “Esophagus, distal and GE junction biopsies” (site not further clarified in available documentation) with Goblet cell carcinoma. The histology code for the goblet cell carcinoma is needed to determine the number of primaries.

In September 2009 the patient was diagnosed with seminoma, classical type, following an orchiectomy. Testicular mass recurrence in 2014 was treated with chemotherapy.

Then in April 2015 a retroperitoneal dissection of a peri-aortic LN was positive for mixed germ cell tumor with somatic type malignancy (rhabdomyosarcoma) involving 1/11 nodes. Path Comment: major component of tumor is teratoma, rhabdomyosarcoma represents <5% of mass.

Now in October 2016, the patient has a retroperitoneal mass biopsy positive for spindle cell sarcoma with rhabdomyosarcomatous differentiation. The comment section of the pathology report states, "Given the history of a germ cell tumor w/ rhadbomosarcomatous component, the findings are consistent with a recurrence of rhabdomyosarcomatous component of germ cell tumor."

Can a seminoma transform to a mixed germ cell tumor with a somatic type malignancy (see SINQ 20140082 - testicular teratoma with somatic type malignancy)?

The pathology report final diagnosis is, "skull base mass, biopsy: neuroendocrine carcinoma, see note. NOTE: Ancillary IHC studies reveal ...the IHC signature is incompatible with ependymoma. The constellation of findings is diagnostic of well differentiated neuroendocrine carcinoma."

The site/histology combination of C410 and 8246/3 is 'impossible' by SEER edits. There is no override. What is the correct primary site and histology?

Patient had a vulvar biopsy with final diagnosis of Extramammary Paget neoplasm (intraepithelial glandular neoplasm). No invasion identified. We are unable to contact the pathologist or physician for clarification.

Although this terminology is not listed in the ICD-O-3, web search results refer to this as a possible synonym for Paget disease with associated VIN III, which is reportable.

Patient has a history of human immunodeficiency virus and diffuse large B cell lymphoma diagnosed in 2012, and is status/post systemic therapy and in remission since completing first course treatment. In 2022, the patient has imaging suspicious for recurrence. A biopsy of a deep left cervical lymph node showed atypical lymphoid infiltrate with the comment: “This is a challenging case. The constellation of findings is most in keeping with early / focal and subtle involvement by a nodular lymphocyte predominant B-cell lymphoma. We find no evidence of involvement by a diffuse large B-cell lymphoma.” The managing physician later states, “Cervical lymph node biopsy (06/2022) was consistent with nodular lymphocyte predominant B cell lymphoma.”