General Surgery Coding Alert

The amount of tissue removednot the intent of the surgeon when the procedure beganis the key to determining whether a partial mastectomy was performed, says Georgeann Edford, RN, MBA, who heads Coding Compliance Solutions, a medical reimbursement firm in Birmingham, MI.

Knowing precisely where a lumpectomy ends and a partial mastectomy begins may be confusing because the usual references are vague on the issue. For example, CPT 1999 offers a short, cut-and-dry descriptor for code 19160mastectomy, partial. No further parameters are given for the code, or how it is distinguished from related codes such as 19120 (excision of cyst, fibroadenoma, or other benign or malignant tumor, aberrant breast tissue, duct lesion, nipple or areolar lesion [except 19140, mastectomy for gynecomastia], male or female, one or more lesions).

Most surgeons will remove a margin of tissue even when they do a biopsy (19100*, biopsy of breast; needle core [separate procedure], or 19101, biopsy of breast; incisional) or perform a lumpectomy. Some believe that such tissue removal qualifies as a partial mastectomy.

Nancy Witts, a coder with a large multispecialty practice in Arizona, says a physician in her practice maintains that if a biopsy already has been taken and comes back from the pathology lab as malignant, the lesion should be excised with clean tissue margins all the way around. At that point, the procedure should be billed as a partial mastectomy.

Witts notes that because CPTs short descriptor makes no mention of the amount of tissue that needs to be removed before 19160 can be charged, the physician should determine whether he or she performed a partial mastectomy.

Medicodes Coders Desk Reference offers a clue that may resolve this problem. In the description of 19160, CDR says the procedure is often referred to as a segmental mastectomy or quadrantectomy, which implies that a significant segment of the breastat least 25 percentwould have to be removed before 19160 could be billed.

Lets say the surgeon started out to do a lumpectomy, but then notes after looking at the tumor or mass that the margins or edges are pretty far out. The surgeon will want to go beyond that to ensure he or she has got the entire mass. If you look at that in relation to the entire breast, and if it equals a quadrant (25 percent), the procedure now becomes a partial mastectomy. But if its less than a quarter, it would have to be billed out as a lumpectomy, Edford says.

Typically, 19120 is coded on the initial excision of the breast mass because most surgeons take a margin of tissue just in case the biopsy returns as malignant so they will not have to perform another excision. Surgeons rarely use 19160 for the initial biopsy because most tumors do not involve 25 percent of the breast. If the margins return positive, which means the tumor has extended beyond the tissue that was excised, they will go back in and do a wider excision. Partial mastectomy usually comes into play at this time and often is combined with axillary lymph node dissection.

Partial Mastectomy and Excision
of Lymph Nodes

When surgeons perform lumpectomies or partial mastectomies, they often perform an axillary lymphadenectomy to remove the lymph nodes between the pectoralis major and the pectoralis minor muscles. They also may remove the nodes in the axilla through a separate incision.

The removal of the axillary lymph node, if performed on its own, would be coded 38745 (axillary lymphadenectomy; complete). But when performed in conjunction with a partial mastectomy or a lumpectomy, both procedures are coded jointly as 19162 (mastectomy, partial; with axillary lymphadenectomy). For coding, Edford says that in such a scenario the use of 19162 means that the lumpectomy is considered a partial mastectomy.

Finally, Edford notes that with partial mastectomies, the surgeon often will return during the postoperative period to see if there has been any lymph node involvement and at that time may remove the nodes. In that case, the lymphadenectomy would be coded 38745 with a -58 modifier (staged or related procedure or service by the same physician during the postoperative period) to indicate it was a staged procedure.