Reportability--Skin: Is a non-small cell carcinoma [8046/3] of the skin SEER reportable?
Non-genital skin primaries with a histology code equal to or less than 8110 are not reportable to SEER; therefore, the combination of C44_ and 8046/3 is not reportable.
Primary Site--Skin: Are perianal skin primaries within 5 cm of the anus coded as perianal skin (C44.5) or anus (C21.0). See Discussion.
ICD-O-3 tells us that perianal skin is C445 and we do not capture basal or squamous cell skin cancers in our registry. The AJCC manual stages perianal skin cancers within 5 cm of the anus with the anus chapter. We cannot AJCC stage them as an anus if we are not capturing them as C445. I realize we do not code a site in order to stage. We have been following the reportability rules and not capturing. Is this correct? I do not see this addressed in the new Other Sites Solid Tumor Rules.
Code primary site based on the site of origin as determined by the physicians. If the physicians state the site of origin is anus, code anus; the same as with skin. As you state, squamous cell cancer of sites coded to C44 is not reportable. The AJCC instruction for physicians to stage perianal neoplasms within 5 cm of the anus using the Anus chapter does not change cancer registry instructions for coding primary site, nor does it affect cancer registry reportability instructions.
Reportability--Skin: Is a pilomatrix carcinoma of the skin reportable if it is described as being a malignant diagnosis based on poor circumscription, infiltrative growth pattern, and focal abundant mitoses?
UPDATED June 2026
Pilomatrix carcinoma is not reportable to SEER. Skin primaries with histology codes from 8090 to 8110 are not reportable. Pilomatrix carcinoma is coded 8110/3.
See the SEER Coding Manual under Reportability, 1b: "Do not report (Exceptions to reporting requirements)"
Reportability--Skin: Is low grade trichoblastic carcinoma, with a small focus of high grade carcinoma of the scalp reportable? See discussion.
Pathology report states: the individual nodules of trichoblastic cells resemble those seen in trichoblastoma, but the lesion is very poorly circumscribed with an infiltrative border that extends into the subcutis. the lesion may behave in a locally aggressive fashion, and should be completely removed. High grade trichoblastic carcinomas can metastasize.
Trichoblastic carcinoma of the skin is not reportable. The WHO classification lists trichoblastic carcinoma as a synonym for basal cell carcinoma, 8090/3. Basal cell carcinoma of the skin is not reportable. See page 11 in the SEER manual, http://seer.cancer.gov/manuals/2015/SPCSM_2015_maindoc.pdf.
MP/H Rules/Recurrence--Skin: If a pathologist does not review the August 2008 slides, how many primaries are accessioned for a patient diagnosed and treated for a dermatofibrosarcoma protuberans of the left upper inner arm in August 2008 who subsequently had a "recurrence" noted in October 2010 located in the scar of the original primary?
Abstract as a single primary: dermatofibrosarcoma protuberans [8832/3] of the left upper inner arm [C446] diagnosed in August 2008.
The rationale for this answer was provided by subject matter experts. The physician specialists for soft tissue and bone replied as follows:
Low-grade sarcomas tend to recur locally. Because this tumor recurred in same area, i.e. scar of prior surgery, and recurred in this period of time, this is a local recurrence. Dermatofibrosarcoma Protuberans is a low grade tumor which can recur many years following tumor excision.
Primary Site--Skin: Should cutaneous leiomyosarcoma be coded to primary skin of site (C44_) or soft tissue (C49_)?
Code cutanteous leiomyosarcoma to skin. Leiomyosarcoma can originate in the smooth muscle of the dermis. The WHO classification designates this as cutaneous leiomyosarcoma. The major portion of the tumor is in the dermis, although subcutaneous extension is present in some cases.
SEER Manual/Reportability--Skin: Is keratoacanthoma (8071/3) of the skin reportable? This code is also for squamous cell carcinoma (SCC), keratinizing. In the 2024 SEER manual, 8071/3 falls under the not reportable section of skin (outside of specific sites).
Do not report keratoacanthoma of the skin (8071/3). The preferred term for keratoacanthoma is squamous cell carcinoma (SCC), keratinizing, NOS. According to the 2024 SEER Manual, Reportability section, SCC of skin (8050-8084) is not reportable.
Reportability/Histology--Skin: Is dermatofibrosarcoma protuberans (DFSP) with fibrosarcomatous overgrowth, DFSP with fibrosarcomatous component Grade 2, or DFSP with focal myxoid features (2022) reportable for 2021-2022 diagnoses?
Yes. DFSP with fibrosarcomatous overgrowth and DFSP with fibrosarcomatous component Grade 2 are synonymous with fibrosarcomatous DFSP (8832/3). Our expert pathologist also advises that DFSP with focal myxoid features is the same as DFSP, myxoid (8832/3).
Reportability--Skin: Is a "basal cell carcinoma of the skin of the lip with focal skin appendage differentiation" reportable?
The histology code for basal cell carcinoma with skin appendage differentiation is 8098/3. Basal cell carcinomas (8090-8110) are not reportable to SEER. Skin appendage tumors are not reportable to SEER unless stated to be carcinoma or stated to be malignant.
According to our pathologist consultant, basal cell carcinoma with focal skin appendage differentiation is basal cell carcinoma which exhibits adnexal (appendage) features, but it is still basal cell carcinoma.
MP/H Rules/Histology--Skin: How is the histology coded for "infiltrative carcinoma with ductal alterations compatible with squamoid eccrine ductal carcinoma" of the skin?
Code the histology to 8413/3 [eccrine adenocarcinoma]. This is the most specific code available for this diagnosis.
According to our expert pathologist advisor, "The adnexal glands in the skin, sweat (eccrine) glands and apocrine glands, all have ducts which connect the business portion of each gland to the skin surface. Some of the adnexal tumors have features of differentiation which appear to be duct-like, hence the designation 'ductal.'"
In addition, "The 'squamoid' simply indicates some degree of squamous differentiation, but doesn't alter the usefulness of [code 8413/3] because we have no way of coding anything more specific in this case anyway."