Histological percutaneous diagnosis of stage IV microcystic serous cystadenocarcinoma of the pancreas

Abstract

SUMMARYMalignant serous cystic neoplasms (SCN) of the pancreas are exceptionally rare, and only a few cases have been reported. As a result, SCN have been unanimously classified as benign tumours. Contrary to this conviction, in 1989, George et al published the very first case of a patient found to have a malignant pancreatic SCN. Up to the time of the submission of this paper, 27 cases of serous cystoadenocarcinomas have been published. In all the previously published cases of malignant SCN, the correct diagnosis was made postoperatively or at the time of autopsy. The authors present a case of a 68-year-old patient who was incidentally found to have a large liver mass on transthoracic echocardiogram ordered for suspected coronary artery insufficiency. Subsequent investigations revealed an additional large mass in the pancreas and percutaneous biopsies of both lesions revealed histological features consistent with malignant SCN metastasised to the left hepatic lobe. BACKGROUND

Serous Neoplasms of the Pancreas

“…For cases with liver involvement, 24,26,29,30,33,34,39,40,43,44,[46][47][48][49] which naturally had been classified as liver "metastasis" at the time (which is certainly a legitimate impression when each case is considered in isolation), a critical review of our cohort and the literature reveals that true malignant behavior is exceedingly uncommon in these tumors. For cases with liver involvement, which had naturally been classified as "metastasis" at the time (and that certainly is what they appear to be when each case is taken in isolation), a critical review of the literature as a whole brings up an alternate possibility of "multifocal" disease rather than true metastasis at least for some of these cases, because of the following reasons: (1) none of them were reported to have further malignant behavior or fatality; (2) there was no metastasis to organs other than the liver, nor was there remote nodal metastasis (most epithelial tumors that metastasize to the liver also typically metastasize to remote lymph nodes first); (3) in the authors' files the occurrence of a liver SCN without a pancreatic "primary" proves that hepatic SCNs can occur independently; (4) there is the well-known, yet peculiar phenomenon of synchronous and metachronous hepatic and pancreatic affliction by other cystic lesions including VHL-associated (a known factor in SCN) polycystic disease and MCN; and (5) all reported cases had a bland cytology (and lacked histomorphologic evidence of malignancy).…”

“…These patients were predominantly female (F:M, 2.17:1), with a mean age of 55 years (which is younger than that of "noninvasive" serous neoplasms), and had a mean follow-up of 4.3 years (range, 0 mo to 19 y); 9 were asymptomatic or incidentally discovered (Table 4), and 27 were reported to have either direct invasion of locoregional structures or lymph nodes (without liver metastasis) 11,25,27,28,32,[35][36][37][38]41,43,45 and mostly documented radiologic (rather than pathologic) impression of "invasion." Although some of these were characterized by the authors as "malignant" or "cystadenocarcinomas," 28,31,[35][36][37][38][39][40]42,44,45,48,49 they would no longer be classified as cystadenocarcinoma by the 2010 …”

“…Reports in the literature describing serous neoplasms "metastatic" to the liver were limited, 24,26,29,30,33,34,39,40,43,44,[46][47][48][49] and of these 10 (59%) had metachronous 26,29,33,34,39,40,43,44,46,47 and 7 (41%) had synchronous liver serous neoplasms, 24,30,39,43,48,49 with 1 case being clinically suspicious for VHL disease. 24 During the documented follow-up period (range, 0 to 19 y; mean, 4.6 y), 3 of these patients died (1 of unrelated disease, 46 another from surgical complications, 24 and the third reportedly of disease progression [this tumor was never resected, nor confirmed on detailed histologic evaluation]).…”

Malignant pancreatic serous cystic neoplasms: systematic review with a new case

“…Direct invasion of the adjacent organs and the presence of distant metastases are hallmarks of malignant SCNs of the pancreas. Although, the 2010 WHO classification defined malignancy by the presence of distant metastases regardless of benign-looking histologic features, the WHO classification is still under debate as many studies have classified SCNs that invade surrounding organs as malignant SCNs [ 4 , 9 , 12 , 13 , 16 , 21 , 22 , 24 , 25 , 27 , 29 , 33 ]. However, it is difficult to differentiate local invasion from mass effect in a large tumor, particularly on preoperative imaging studies.…”

“…In the 2010 WHO classification, malignancy is defined by the presence of distant metastases regardless of benign-looking histologic features. However, the WHO classification is still under debate as many studies have classified SCNs that invade surrounding organs as malignant SCNs even though there is no distant metastasis [ 4 , 9 , 12 , 13 , 16 , 21 , 22 , 24 , 25 , 27 , 29 , 33 ]. Therefore, in this article, we use the broad term ‘malignant SCNs’ to include either SCNs with distant metastasis or local invasion.…”