LCD L35702: Mohs Micrographic Surgery

Coverage Indications, Limitations, and/or Medical Necessity

As defined by the American Medical Association Current Procedural Terminology (American Medical

Association, Chicago, IL), Mohs Micrographic Surgery (MMS) is a technique for the removal of complex or ill-defined skin cancer with histologic examination of 100% of the surgical margins. It is a combination of surgical excision and surgical pathology that requires a single physician to act in 2 integrated but separate and distinct capacities: surgeon and pathologist. If either of these responsibilities is delegated to another physician who reports the services separately, these codes should not be reported. The Mohs surgeon removes the tumor tissue and maps and divides the tumor specimen into pieces, and each piece is embedded into an individual tissue block for histopathologic (hematoxylin-eosin or toluidine blue) examination. Thus, a tissue block in MMS is defined as an individual tissue piece embedded in a mounting medium for sectioning. (American Medical Association. Mohs Micrographic Surgery. CPT Assistant 2006;16:1-7)

Mohs micrographic surgery is a two-step process: the tumor is removed in stages, followed by immediate histologic evaluation of the margins of the specimen(s). Further excision is performed until all margins are clear. The physician performing MMS furnishes both the surgical and pathological services, i.e., the excision and the histologic evaluation of the specimen(s).

Mohs surgery is usually an outpatient procedure done under local anesthesia (with or without sedation).

The majority of simple skin cancers can be managed by simple excision or destruction techniques. The medical records should clearly document that Mohs surgery was chosen because of the complexity (e.g. poorly defined clinical borders, possible deep invasion, prior irradiation), size or location (e.g. maximum conservation of tumor-free tissue is important).

Indications:

After careful review Medicare Jurisdictions E and F have adopted coverage for Mohs Micrographic Surgery in accordance with the 2012 Appropriate Use Criteria (AUC) for Mohs Micrographic Surgery as published in the Journal of the American Academy of Dermatology Volume 67, Issue 4, pp 531-550, October 2012. These criteria were compiled based on collaboration of the American Academy of Dermatology, the American College of Mohs Surgery, the American Society of Dermatologic Surgery Association and the American Society for Mohs surgery based on evidence based medicine, clinical practice experience and expert judgment.

Clinical settings that are supported by the criteria as denoted by the CPT ® codes and ICD-10-CM codes listed in the Billing and Coding Article will be considered for coverage when properly performed and the indications, procedure and findings/results clearly and legibly documented within the beneficiary’s clinical record. Clinical settings noted to be inappropriate by the criteria and not otherwise covered in this LCD will be denied and should NOT be billed to Medicare as MMS.

The majority of simple skin cancers can be managed by simple excision or destruction techniques. The medical records should clearly show that MMS was chosen because of the complexity (e.g. poorly defined clinical borders, possible deep invasion, prior irradiation), size or location (e.g. maximum conservation of tumor-free tissue is important).

Definitions:

1. Area H: Mask areas of the face (central face, eyelids [including inner/outer canthi], eyebrows, nose, lips [cutaneous/mucosal/vermillion], chin, ear and periauricular skin/sulci, temple), genitalia (including perineal and perianal areas), hands, feet, nail units, ankles, nipples/areola.

2. Area M: Cheeks, forehead, scalp, neck, jawline, pretibial surface.

3. Area L: Trunk and extremities (excluding pretibial surfaces, hands, feet, nail units and ankles).

4. Immunocompromised: a patient with HIV/AIDS, organ transplant, hematologic malignancy or pharmacologic suppression.

5. Genetic Syndromes: basal cell nevus syndrome, xeroderma pigmentosa, or other syndromes at high risk for skin cancer.

6. Healthy: no immunosuppression, no prior radiation therapy to affected area, no chronic infections and no genetic syndromes that predispose to skin cancer.

7. Prior Radiated Skin: patient has previously received therapeutic radiation in this area of the body.

8. Aggressive features:

a. For Basal Cell Carcinoma

i. Morpheaform, fibrosing, sclerosing

ii. Infiltrating

iii. Perineural

iv. Metatypical/keratotic

v. Micronodular

b. For Squamous Cell Carcinoma

i. Sclerosing

ii. Basosquamous excluding keratotic BCC

iii. Small cell

iv. Poorly or undifferentiated, i.e. high degree of polymorphism, high mitotic rate and/or low degree of keratinization

v. Perineural or perivascular

vi. Spindle cell

vii. Pagetoid

viii. Infiltrating

ix. Keratoacanthoma (KA) type: central facial

x. Single Cell

xi. Clear Cell

xii. Lymphoepithelial

xiii. Sarcomatoid

xiv. Breslow depth below 2mm or greater

xv. Clark level IV or greater

9. Tissue Block:

A block is the plate that tissue is placed upon, coated with embedding medium, frozen, and then placed into the microtome for cutting. Thus, a block is a plate with tissue and mounting medium on it. How many tissue pieces go onto the plate (block) does not matter. The technician, with possible input from the physician, decides how many tissue pieces from a given excision stage would fit on one tissue plate (block). For example, a specimen may be butterflied and put on one block (tissue plate), or the same specimen could be bisected and both tissue pieces put on one plate (block). It is still one block.

Another example: one may take a subsequent Mohs excision stage as three separate, non-contiguous pieces (specimens). Each of the tissue pieces is considered as a separate tissue specimen; however, depending upon their size and the technician's proficiency, all three pieces could be placed upon one plate (one block), or two pieces on one plate and one on another plate (2 blocks), or each of the three tissue pieces (specimens) could be placed on individual plates (3 blocks).

The block is the billing unit, not the tissue piece.

Indications:

Medicare will consider reimbursement for MMS for the following indications and anatomic locations:

I. Basal Cell Carcinoma

A. Recurrent BCC of any size or unexpected positive margin on recent excision (healthy or immunocompromised or genetic syndrome(s))

i. Aggressive Pathology

1. Area H, M, and/or L

ii. Nodular pathology

1. Area H, M, and/or L

iii. Superficial pathology

1. Area H and M only

2. No coverage for Area L

B. Primary Aggressive

i. Size ≤ 0.5 cm

1. Area H and M.

2. Area L may be covered on redetermination

ii. Size ≥ 0.6 cm

1. Area H, M, and L

C. Primary Nodular BCC (Healthy patient)

i. Size ≤ 0.5 – 1 cm

1. Area H and M only

2. No coverage for Area L

ii. Size 1.1 – 2 cm

1. Area H and M.

2. Area L may be covered on redetermination

iii. Size ≥ 2

1. Area H, M, and L

D. Primary Nodular BCC (Immunocompromised patient)

i. Size ≤ 0.5 cm

1. Area H and M only

2. No coverage for Area L.

ii. Size 0.6 – 1 cm

1. Area H and M.

2. Area L may be covered on redetermination

iii. Size ≥ 2 cm

1. Area H, M, and L

E. Primary Superficial BCC (Healthy Patient)

i. Size ≤ 0.5 cm

1. Area H.

2. Area M may be considered for coverage on redetermination.

3. No coverage for Area L.

ii. Size ≥ 0.6 cm

1. Area H and M.

2. No coverage for Area L.

F. Primary Superficial BCC (Immunocompromised Patient)

i. Size ≤ 1.0 cm

N/A