Mucinous components assessed by magnetic resonance imaging in primary rectal cancer tissue before and after chemoradiotherapy and tumor response.

BACKGROUND: Mucinous rectal carcinoma has been reported to have a lower survival rate and a poorer histologic response to chemoradiotherapy(CRT). Magnetic resonance imaging (MRI) can accurately evaluate the amount of mucin pools (MP) in primary cancer tissue. We compared the degree of MP on MRI before and after CRT with the histologic findings of resected specimens to investigate the predictors of response to CRT. METHODS: The study group comprised 205 patients with rectal adenocarcinoma who received preoperative CRT. MPs were measured on MRI before and after CRT and in resected specimens. The degree of MP was classified into five classes according to the MP area ratio: 0%, class I; 1 to 19%, class II; 20 to 49%, class III; and 50% or higher, class IV. RESULTS: The degree of MP on MRI was largely unchanged after CRT; however, the MP on MRI after CRT was underestimated in 26.3% of patients as compared with that in resected specimens. A pathological complete response was obtained in patients who initially had no MP or had an MP ratio of less than 20%. The tumor volume was significantly greater, and the rates of tumor shrinkage and T downstaging were significantly lower in patients who had an MP area ratio of 20% or higher before CRT than in those who had an MP area ratio of less than 20%. CONCLUSIONS: The MP area ratio measured on MRI before treatment was closely associated with the response to CRT and is a potentially useful predictor of treatment response.

Clinical significance of carcinoembryonic antigen expression of acellular mucin pools after preoperative chemoradiotherapy of rectal carcinoma.

INTRODUCTION: Although several studies have shown that the presence of acellular mucin pools in surgical specimens with rectal carcinomas examined after preoperative chemoradiotherapy indicated complete response to therapy, the proper meaning of these pools has yet to be elucidated. The aims of this study were to analyze the immunoprofile of acellular mucin pools and to review the relevant literature. METHODS: In 30 consecutive rectal cancers that were preoperatively treated with chemoradiotherapy, the clinicopathologic features were correlated with the immunoexpression of AE1/AE3 keratin and carcinoembryonic antigen (CEA). RESULTS: Acellular mucin pools were present in all the cases, independently by their preoperative histological aspect. In remnant tumors (n=20), they were present at the invasion front and were marked by CEA. In cases without remnant tumor cells (n=10), they also displayed CEA positivity. In 2 of the 10 cases, isolated tumor cells were identified after multilevel sectioning of paraffin-embedded blocks. CONCLUSIONS: The presence of acellular mucin pools in surgical specimens of rectal cancers cannot be interpreted as an indicator of complete response to radiotherapy if at least 10 multilevel sections are performed in at least three tumor blocks per case, and CEA negativity is not proved.

A Case of Primary Mucinous Eccrine Carcinoma in the Lower Eyelid Skin

Primary mucinous eccrine carcinoma(MEC) of the skin, one of sweat gland tumor, is a rare. These tumors usually occur in one's fifties and seventies, and are characterized by the secretion of mucin that usually forms the pools surrounding the clusters of tumor cells. The common sites are the eyelids and medial canthus. Pathologically it is difficult to distinguish between primary mucionus carcinoma and metastatic cancers from breast, rectum, colon, bronchus, kidney, ovary, stomach, lacrimal glands, salivary glands, and paranasal sinuses. Therefore study for primary focus is needed. A 62-year-old mand has had a mass on left lower eyelid skin without palpable neck lymph nodes for about five years. In a fine needle aspiration, there were tumor cells floating in a mucin pool. The authors examined several tests including complete blood cell count, liver function test, renal function test, urinalysis, electrocardiography, VDRL, TPHA-S, chest X-ray, chest computed tomography(CT), neck CT, abdominopelvic CT, etc. All the tests showed the origin was the skin. It is diagnosed to primary MEC on skin. The tumor was treated by wide excision with 0.5cm in safe margin and full thickness skin graft was done. There has been no recurrence 10 months after operation.

A Case of Gastric Mucinous Adenocarcinoma Presenting as a Characteristic Mucin Pool / 대한소화기내시경학회지

Mucinous adenocarcinoma is a rare histologic type of gastric carcinoma. Most mucinous gastric carcinoma is diagnosed by histology after surgical resection. However, in this report, we preoperatively predicted the type of a tumor (mucinous type) from its characteristic endoscopic finding. An endoscopic examination showed a cauliflower-like mass on the upper body of the posterior wall. At first we could not find the mass because it was covered with a thick mucin-like substance. After gastric lavage and mucin aspiration we found a tumor mass which was surrounded with a characteristic mucin pool. Abdominal CT showed a 6 cm sized-mass connected with the gastric fundus. Total gastrectomy with esophagojejunostomy was performed. The pathology of the tumor proved to be a mucinous adenocarcinoma.