Skin Neoplasms: Uncover the Facts for More Precise Diagnosis Coding
Stellar skin cancer coding requires more than just an understanding of ICD-9-CM principles for neoplasms.
By Betty Hovey, CPC, CPMA, CPC-I, CPB, CPC-H, CPCD
The more you know about skin cancer and anatomy, the easier it will be to code for benign and malignant neoplasms diagnoses using ICD-9-CM guidelines and proper sequencing. Let’s start with the basics.
Differentiate Skin Cancers
According to the Centers for Disease Control and Prevention (CDC), skin cancer is the most common form of cancer in the United States. The primary cause is ultraviolet radiation, most often from the sun. Skin cancers are named for the type of cells affected. The three principal types are basal cell carcinoma, squamous cell carcinoma, and melanoma.
Basal Cell Carcinoma (BCC)
Basal cell carcinoma is the most common form of skin cancer, and the most common of all cancers. More than one in three cancers is a skin cancer, and most of these (more than two million per year in the United States) are BCC, ac-cording to the American Academy of Dermatology (AAD).
Basal cell carcinoma starts in the epidermis and usually develops on the sun-exposed areas of the body, such as the scalp, face, and (especially) the nose. BCC almost never spreads to other parts of the body.
Squamous Cell Carcinoma (SCC)
Squamous cell carcinoma is the second most common skin cancer. The AAD reports about 700,000 new cases of SCC each year.
This form of skin cancer usually remains confined to the epidermis for some time, but eventually will penetrate to the underlying tissues if not treated. As with basal cell carcinoma, SCC most often occurs on sun-exposed areas of the body, including the face, neck, bald scalps, hands, arms, and back.
Melanoma is the most serious type of skin cancer. In 2009, the CDC indicated over 61,000 newly diagnosed cases of melanoma and over 9,000 melanoma-related deaths. If diagnosed and treated early, however, melanoma is almost 100 percent curable.
There are four types of melanoma: superficial spreading melanoma (most common), lentigo maligna (melanoma in situ), acral lentiginous melanoma, and nodular melanoma.
Ready to Code? Refer to ICD-9-CM Guidelines
Guidelines for neoplasms may be found in section I.C.2 of the ICD-9-CM manual. Chapter 2 of ICD-9-CM contains the codes for most benign and all malignant neoplasms (the relevant codes are in the range 140-239). To assist in code selection, the ICD-9-CM Index contains a Neoplasm Table located under the primary heading “Neoplasm.” To confirm neoplasm location and behavior (primary, secondary, in situ, etc.), you ideally should have a pathology report available. It’s important to have a confirmed diagnosis because to label a patient with an unconfirmed diagnosis (especially a diagnosis of cancer) may lead to serious negative consequences.
If a histologic term (adenoma, melanoma, etc.) is documented, you should first reference that term, rather than going to the Neoplasm Table. Sometimes the referenced term will instruct you to go to the Neoplasm Table; sometimes it will give you code choices to reference in the Tabular List.
Melanoma is a good example of when you should use the alphabetical Index to locate a code in the Tabular List.
Case In Point
A patient has a melanoma on the skin of the nose. If you use the Neoplasm Table, you would look up “skin,” with the subterm “nose,” which would send you to “Neoplasm, skin, face.” Under “face,” there are choices of “basal cell,” “specified type,” and “squamous cell.” You might consider the “specified type” as the correct choice because melanoma is specified, which would lead you to 173.39 Other specified malignant neoplasm of skin of other and unspecified parts of face. But if you first reference the alphabetical Index for the term “melanoma,” with the subterm “nose,” you would instead be sent to 172.3 Malignant melanoma of other and unspecified parts of face, which is the more precise and correct code.
Always look first under any documented terms provided before accessing the Neoplasm Table to ensure the most ap-propriate code selection.
Sequencing Is Important
Sequencing of codes may be a factor when reporting neoplasms. Instructions may be found in the ICD-9-CM Official Guidelines for Coding and Reporting (I.C.2.a – I.C.2.c).
If treatment is directed at the malignancy, the malignancy should be the first-listed code. The exception to this rule is when a patient presents solely for administration of chemotherapy/immunotherapy/radiation therapy. At that point, an appropriate code from category V58 Encounter for other and unspecified procedures and aftercare would be the first-listed code because that is the main reason the patient is presenting, followed by the neoplasm code.
The V58 category code choices are:
V58.0 Encounter for radiotherapy
V58.11 Encounter for antineoplastic chemotherapy
V58.12 Encounter for antineoplastic immunotherapy
If the patient has a metastatic malignancy, the order of the codes is driven by the reason for the encounter. If it’s for the primary site, that is the first-listed code. If it’s for the secondary site, it will be the first-listed code. Documentation must be clear to ensure codes are properly reported in the correct order.
Case In Point
A patient with melanoma of the thigh that has spread to the inguinal lymph nodes presents for interferon alpha 2-b im-munotherapy treatment for the metastatic site of the lymph nodes.
Proper coding and sequencing is:
196.5 Secondary malignant neoplasm of the lymph nodes of inguinal region and lower limb
172.7 Malignant melanoma of skin of lower limb, including hip
In a second example, a patient presents to have a basal cell carcinoma excised from his nose and a basal cell carcinoma excised from his back.
Proper coding is:
173.31 Basal cell carcinoma of other and unspecified parts of the face
173.51 Basal cell carcinoma of skin of trunk, except scrotum
There is no sequencing rule when a patient has two primary carcinomas and presents for treatment for both. 173.31 and 173.51 are the proper codes, but the codes do not have to be in this order.
The ICD-9-CM Official Guidelines for Coding and Reporting also gives instruction on many other issues pertaining to skin cancer, including coding for complications, encounters for surgical removal, and encounters for pain control/pain management. Be sure to look to these guidelines if you need clarification on a diagnosis coding issue.
Know Skin Anatomy and Function
The skin is the largest organ system of the body. It’s made up of two layers: the epidermis and the dermis. The epidermis has four to five layers, called stratum, which include the stratum corneum, stratum lucidem, stratum granulosum, stratum spinosum, and stratum basale. The stratum basale is the layer of reproducing cells that lies at the base of the epidermis and receives its nourishment from dermal blood vessels.
The epidermis contains mostly dead cells and has no blood vessels. The epidermis contains melanocytes, which are cells that produce melanin, a dark brown pigment. The difference in people’s skin color comes from the amount of melanin melanocytes produce and distribute.
The epidermis is important because it protects against water loss, mechanical injury, chemicals, and microorganisms.
The dermis has two layers (papillary dermis and reticular dermis) and lies under the epidermis. The dermis contains structures that nourish and innervate the skin. They are nerves/nerve endings, cutaneous blood vessels, hair, nails, and glands. The dermis binds the epidermis to underlying tissues and consists of connective tissue with collagen and elastic fibers within a gel-like ground substance.
Below the dermis lies the subcutaneous tissue. The subcutaneous tissue is made up of loose connective tissue and adipose tissue, which provides insulation and protection for deeper structures. It binds the skin to underlying organs and contains the blood vessels that supply the skin with blood.
Betty Hovey, CPC, CPMA, CPC-I, CPB, CPC-H, CPCD, is AAPC’s director of ICD-10 Development and Training. She is a member of the Frankfort, Ill. local chapter.