A multi-institutional study was undertaken to determine whether mandibular canal (MC) invasion and mandibular medullary bone invasion are independent factors in lower gingival squamous cell carcinoma (SCC). A total of 345 patients with lower gingival SCC were retrospectively reviewed. Mandibular bone invasion was categorized into three types; no bone invasion; invasion through cortical bone (me...

BACKGROUND Melanin production in medullary carcinoma is extremely uncommon. CASE PRESENTATION We report a rare variant of medullary carcinoma of thyroid with melanin production in a 52-year-old woman who presented with swelling in the thyroid of 3 months duration. This tumor recurred thrice in two years after surgery and patient died with metastasis. Microscopic examination showed typical mor...