Clinical and pathologic correlation of 84 mucinous cystic neoplasms of the pancreas: can one reliably differentiate benign from malignant (or premalignant) neoplasms?

OBJECTIVE

To determine whether the long-term behavior of cystic mucinous neoplasms of the pancreas could be predicted using a novel, precisely defined classification of benign mucinous cystadenomas, noninvasive proliferative cystic mucinous neoplasms, and invasive mucinous cystadenocarcinomas. The primary interest was to obtain long-term follow-up after complete resection to determine the recurrence rates based on this objective classification.

BACKGROUND

Current understanding is that all cystic mucinous neoplasms of the pancreas are potentially malignant and that mucinous cystadenomas, when completely removed, are biologically benign. Cystadenocarcinomas are thought to be less aggressively malignant than ordinary ductal adenocarcinoma, but reported recurrence rates vary widely and are unpredictable.

METHODS

All patients who underwent "curative" resection for cystic mucinous neoplasms at Mayo Clinic Rochester from 1940 to 1997 were identified. All available pathology slides, gross specimens, and clinical records were reviewed, eliminating patients with inadequate documentation. Neoplasms were reclassified as mucinous cystadenomas, noninvasive proliferative mucinous cystic neoplasms, or invasive cystadenocarcinomas based on specific histologic criteria.

RESULTS

Of 84 patients (70 women, 14 men) with cystic mucinous neoplasms of the pancreas, 54 were classified as cystadenomas, 23 as noninvasive proliferative cystic mucinous neoplasms, and only 7 as cystadenocarcinomas. Recurrent disease developed in none of the 77 patients without invasion, but 5 of the 6 patients surviving resection for cystadenocarcinomas died of recurrent cystadenocarcinoma within 5 years.

CONCLUSIONS

When the neoplasm is completely resected and subjected to adequate histopathologic examination based on these objective criteria, absence of tissue invasion predicts a curative operation and detailed follow-up may be unnecessary. In contrast, a histologic diagnosis of invasive cystadenocarcinoma portends a dismal prognosis, similar to that of typical ductal adenocarcinoma of the pancreas.

The care and cost of snowmobile-related injuries

From January 1, 1991, through May 1, 1993, we identified 42 patients from our prospective computer-based trauma registry (38 males, four females; mean age, 25 years) who were hospitalized after snowmobile accidents. The primary reason for hospitalization varied: bone fracture (n = 18), blunt abdominal trauma (n = nine), closed head injury (n = five), and miscellaneous injuries (n = 10). The mean injury Severity Score was 9.3 (range, one to 43; median, nine). Twenty-six patients (62%) required emergent operation. Mean hospital stay was six days (range, one to 16 days). Thirteen patients had complications: seven had wound infection; three, ileus; and three, miscellaneous. One severely injured hypothermic patient died. Medical charges totaled $569,566 (mean, $16,227; range, $1,003 to $51,642). Snowmobiling causes significant accidental injury in young persons. The physical and financial costs of such injuries are high.