Mucinous Cystic Neoplasm : Invasive Carcinoma
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Mucinous Cystic Neoplasm (MCN) with Invasive Carcinoma: About 15% of MCNs have an associated invasive carcinoma. Since invasive areas may be small and focal, thorough sampling (or even submitting entirely) is recommended. The entire circumference of the cyst wall and any solid nodules within or adjacent to the cyst must be evaluated histologically.
The invasive component occurs more frequently in large tumors (> 5 cm) with intracystic mural nodules and grossly recognizable papillary architecture. Despite the presence of invasive carcinoma, lymph node metastases are extremely rare in MCNs.
Microscopically, the invasive component is tubular/ductal type adenocarcinoma. Uncommon patterns include adenosquamous, undifferentiated carcinoma with osteoclast-like giant cells, and MCN with sarcomatous stroma. Colloid carcinoma is not seen in MCNs.
In a large study of 163 MCNs, 82.5% were low-grade, 5.5% were high-grade, and 12% had invasive carcinoma. Of the invasive tumors, 8% were microinvasive with invasion confined to the ovarian stroma (as seen in this case) or capsule and 4% invaded the surrounding pancreas or extrapancreatic tissue.
The invasive component occurs more frequently in large tumors (> 5 cm) with intracystic mural nodules and grossly recognizable papillary architecture. Despite the presence of invasive carcinoma, lymph node metastases are extremely rare in MCNs.
Microscopically, the invasive component is tubular/ductal type adenocarcinoma. Uncommon patterns include adenosquamous, undifferentiated carcinoma with osteoclast-like giant cells, and MCN with sarcomatous stroma. Colloid carcinoma is not seen in MCNs.
In a large study of 163 MCNs, 82.5% were low-grade, 5.5% were high-grade, and 12% had invasive carcinoma. Of the invasive tumors, 8% were microinvasive with invasion confined to the ovarian stroma (as seen in this case) or capsule and 4% invaded the surrounding pancreas or extrapancreatic tissue.