## Core Concept
Mohs Micrographic Surgery (MMS) is a precise surgical technique used for the excision of skin cancers, particularly for tumors with high recurrence rates or in cosmetically sensitive areas. It involves the examination of the entire tumor margin to ensure complete removal while sparing as much normal tissue as possible. Basal cell carcinoma (BCC) is a type of skin cancer for which MMS can be an effective treatment.

## Why the Correct Answer is Right
The correct answer, **D. Large and deeply invasive tumors**, indicates a scenario where Mohs Micrographic Surgery might not be the preferred initial treatment. MMS is highly effective for well-defined, localized tumors, especially in cosmetically sensitive areas or where tissue sparing is crucial. Large and deeply invasive tumors, however, may require a more extensive surgical approach or other treatments like excision with clear margins followed by reconstruction, due to their size and depth of invasion.

## Why Each Wrong Option is Incorrect
- **Option A: Tumors in cosmetically sensitive areas** - Mohs Micrographic Surgery is particularly beneficial for tumors located in areas like the face, where preserving as much normal tissue as possible is crucial for cosmetic and functional reasons.
- **Option B: Tumors with aggressive histology** - For aggressive forms of basal cell carcinoma, such as infiltrative or morpheaform types, Mohs surgery provides the advantage of margin control, which is critical for ensuring complete removal.
- **Option C: Recurrent tumors** - Mohs Micrographic Surgery is often recommended for recurrent basal cell carcinomas because it allows for precise margin assessment and can be more effective in achieving clear margins in previously treated and potentially scarred tissue.

## Clinical Pearl / High-Yield Fact
A key point to remember is that Mohs Micrographic Surgery is highly effective for well-defined, localized skin cancers, particularly in cosmetically sensitive areas or for tumors with aggressive histological features. It's essential to consider the size, location, and histology of the tumor when deciding on the most appropriate surgical approach.

## Correct Answer: D. Large and deeply invasive tumors