Melt the butter in a large saucepan over medium-low heat. Add the mushrooms, onion, celery and carrot. Cook and stir until tender, about 10 minutes. Stir in the chicken stock and season with salt and cayenne pepper. Bring to a boil, then simmer for 10 minutes.
Pour the vegetable and stock mixture into the container of a blender and add 1/4 cup of the lobster meat. Cover and blend until smooth. Return to the saucepan and stir in the cream, white wine and remaining lobster meat. Cook over low heat, stirring frequently until thickened, about 30 minutes.