Surgery of Primary Site--Breast: How is this field coded when a mastectomy and a sentinel lymph node excision, that yields only one lymph node, are performed? See Discussion.
Is there a minimum number of lymph nodes that must be removed in order to code a modified radical mastectomy?
Assign code 41 [Total (simple) mastectomy...] for a simple mastectomy with removal of one or more sentinel lymph nodes. As long as the nodes removed are designated sentinel, use code 41 for a simple mastectomy.
Surgery of Primary Site--Skin: Should Mohs surgery be code to 27 [Excisional biopsy] or 31 [Shave biopsy followed by a gross excision of the lesion]? See discussion.
Under surgery coding in the 5/22/01 SEER Abstractor/Coder Workshop book, page 20, it states that Mohs surgery should be coded as an excisional biopsy. The ACoS I&R dated 6/6/2001 states that it should be coded to 31.
For cases diagnosed 1/1/2003 and after: Code the Surgery of Primary Site field to 34 [Mohs surgery, NOS], 35 [Mohs with 1-cm margin or less] or 36 [Mohs with more than 1-cm margin].
Surgery of Primary Site--Breast: How is this field coded for cryosurgery of the breast?
For cases diagnosed 2003 and later: For cryosurgery alone, without a pathology specimen, assign site-specific surgery code 19 [Local tumor destruction, NOS]. Cryosurgery, cryotherapy or cryoablation uses extreme cold to destroy the tumor cells.
If a specimen is sent to pathology use code 20 [Partial mastectomy, NOS] rather than code 19.
If cryosurgery is followed by further surgery, do not use code 19.
Surgery of Primary Site--Lung: How is surgery coded when a patient undergoes a mediastinoscopy with mediastinal lymph node sampling and then a later upper lobectomy? See discussion.
The mediastinal nodes were submitted as a separate specimen. The patient also had several peribronchial nodes identified within the lobectomy specimen.
Does code 33 (Lobectomy with mediastinal lymph node dissection) require a complete mediastinal lymph node dissection (i.e. the removal of all lymph nodes in mediastinal chain(s) as opposed to a selective sampling/dissection of lymph nodes from multiple mediastinal chains)?
Assign code 33 in this situation. Code 33 can include mediastinal lymph node sampling.
Surgery of Primary Site--Lymphoma/Soft Tissue: How is this field coded for an excision of a neck mass that found lymphoma in soft tissue (C49.0)? See Discussion.
CT scan showed soft tissue mass in the retropharynx. 9/23/2008 Laryngoscopy with biopsy taken of left tonsil and left base of tongue and random biopsies of nasopharynx; FNA of left neck. Path stated left tonsil, squamous papilloma. Left base of tongue, no significant histopathology. Nasopharynx biopsies, compatible with tonsillar tissue. Pretracheal lymph node biopsies, mild reactive lymphoid hyperplasia. 9/30/2008 Excision of left neck mass with limited deep jugular chain lymph node dissection. Path stated lymph node left jugular biopsy, no tumor seen. Soft tissue, left neck biopsy, malignant B cell lymphoma with plasmacytoid differentiation. Addendum from consult: favor a diagnosis of a marginal zone lymphoma. Per the gross description, the specimen was fibrofatty connective tissue in which there is a tumor infiltrate.
Updated May 2026
For cases diagnosed prior to 2023:
Assign code 26 [partial resection]. Use the surgery codes that apply to the primary site, C490-C499.
Surgery of Primary Site--Breast: How should the Surgery of Primary Site field be coded when a patient has a lumpectomy and an additional margin excision during the same procedure? See discussion.
Operative report indicates a wire localized lumpectomy was performed. The pathology report includes a final diagnosis for two specimens as follows:
A) LEFT BREAST, EXCISION: INFILTRATING DUCTAL CARCINOMA
B) LEFT BREAST, NEW DEEP MARGIN, EXCISION: BENIGN BREAST TISSUES AND BENIGN FIBROFATTY SOFT TISSUES; NO EVIDENCE OF NEOPLASIA.
The definition for Breast surgery code 23 is "Reexcision of the biopsy site for gross or microscopic residual disease". There is no indication whether the re-excision has to be a separate procedure or can be during the same procedure as the excisional biopsy (lumpectomy). Some hospital registrars in our region believe code 22 is more appropriate.
Revised Answer
Assign code 22 when a patient has a lumpectomy and an additional margin excision during the same procedure.
According to the CoC, "Re-excision of the margins intraoperatively during same surgical event does not require additional resources; it is still 22. Subsequentre-excision of lumpectomy margins during separate surgical event requires additional resources: anesthesia, op room, and surgical staff; it qualifies for code 23."
Surgery of Primary Site--Kidney, renal pelvis: How do you code a laparoscopic renal mass core biopsy followed by cryoablation of the tumor? See Discussion.
The note under the local tumor destruction codes states "No specimen sent to pathology from this surgical event 10-15." The patient had a pathologic specimen submitted from his core biopsy, but this was not a tumor excision or excisional biopsy [codes 20, 26-27]. Is the correct surgery code 13 [cryosurgery] because the tumor was only ablated and not excised, or surgery code 23 [any combination of 20 or 26-27 with cryosurgery] because a pathology specimen was submitted?
Code for Surgery of Primary Site to 13 [Cryosurgery]. While the core biopsy provided a pathology specimen, it is not coded as surgery of the primary site.
Surgery of Primary Site--Skin: Should this field be coded to 45 [wide excision or reexcision of lesion or minor (local) amputation with margins more than 1 cm, NOS], 46 [with margins between 1 and 2 cm], or 47 [with margins greater than 2 cm] for a skin primary diagnosed in 2003 when margins are stated exactly as 2 cm?
Use code 46 [Wide excision...with margins more than 1 cm and less than 2 cm] when margins are exactly 2 cm.
Surgery of Primary Site/Reconstruction-First Course--Breast: If the plan is to "reconstruct" the breast 6 months after an ipsilateral modified radical mastectomy, is the time span a problem or should it be coded in the Surgery of Primary Site field because it was planned?
For cases diagnosed 1/1/2003 and after: Code the Surgery of Primary Site field to 55 [Modified radical mastectomy WITHOUT removal of uninvolved contralateral breast, Implant]. The time span is not a problem as long as the reconstruction was planned as first course, which is indicated by tissue expander insertion at the time of the original surgery.
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