Table 4.
Characteristics of False-Positive Cases of Nonmelanoma Skin Cancer Identified in a Random Sample of 1988–2007 All-Payer Claims Data, by Identification Method, Henry Ford Health System, Detroit, Michigan
| Noncase Reason | ICD-9-CM Alone (n = 185) |
CPT Alone (n = 89) |
Both ICD-9-CM and CPT Codes (n = 15) |
|||
| No. | % | No. | % | No. | % | |
| Atypical melanocytic lesion incorrectly labeled as NMSC (including atypical nevus, blue nevus, melanoma, melanoma in situ) | 16 | 9 | 15 | 17 | 3 | 20 |
| Benign lesion incorrectly labeled with a malignancy code, other than melanocytic | 109 | 59 | 66 | 74 | 1 | 7 |
| Malignancy other than melanoma with its own unique ICD-9-CM code (including mycosis fungoides, vulvar intraepithelial neoplasia, angiosarcoma) | 6 | 3 | 6 | 7 | 1 | 7 |
| Surgical defect repair linked to neoplasm (i.e., repair by plastic surgery after Mohs chemosurgery) and unlinked to neoplasm (i.e., hernia repair) | 1 | 0.5 | 1 | 1 | 7 | 47 |
| Lesion diagnosed visually (without confirmed biopsy/no histopathologic confirmation) and referred for malignant lesion excision | 13 | 7 | 0 | 2 | 13 | |
| New diagnosis discussed/preoperative visit | 6 | 3 | 0 | 0 | ||
| Follow-up or postoperative visit/history of NMSC | 34 | 18 | 1 | 1 | 1 | 7 |
Abbreviations: CPT, Current Procedural Terminology; ICD-9-CM, International Classification of Diseases, Ninth Revision, Clinical Modification; NMSC, nonmelanoma skin cancer.