Adenosquamous carcinoma of the pancreas: preoperative diagnosis and molecular alterations

Abstract

Adenosquamous carcinoma of the pancreas is a rare tumor which has a less favorable prognosis than common ductal cell carcinoma of the pancreas, and a definite preoperative diagnosis of this tumor is quite difficult. We herein report two cases of this rare variant. The patients were a 41-year-old man (patient 1) and a 67-year-old woman (patient 2). Patient 1 had a hypoechoic mass measuring 3 cm in the uncus of the pancreas, while patient 2 had a huge mass, measuring 8 cm, in the tail of the pancreas. Patient 2 was successfully diagnosed preoperatively as having an adenosquamous carcinoma, by cytological examination of the pure pancreatic juice obtained by endoscopic retrograde pancreatic juice aspiration. A pylorus-preserving pancreatoduodenectomy was performed for patient 1, and a distal pancreatectomy with resection of the spleen and the left kidney was performed for patient 2. Subsequent pathological findings of these two tumors revealed adenosquamous carcinoma of the pancreas. K- ras point mutation, p53 overexpression, and telomerase activity in both tumor specimens were detected by the mutant allele specific amplification method, immunohistochemical staining, and telomeric repeat amplification protocol assay, respectively. The two patients died of recurrent disease 5 and 4 months, respectively, after surgery. Cytological examination of pure pancreatic juice is a useful modality for the preoperative diagnosis of this tumor, and frequent molecular alterations may be associated with the poor prognosis of adenosquamous carcinoma of the pancreas.

Adenosquamous carcinoma of the pancreas: Molecular characterization of 23 patients along with a literature review

“…The KI-67 index for one patient with ASCP with approximately a 70%-80% squamous carcinoma component was 33% [32] . As in pancreatic adenocarcinoma, KRAS mutations have also been observed in ASCP [18,27,31,34] . A molecular study involving analysis for p53, Dpc4/SMAD4, p16, E-cadherin, EGFR protein expression levels, KRAS mutational analysis; p16/CDKN2a amplification, and HPV DNA detection was carried out on 8 patients with ASCP [27] .…”

“…The proportion of squamous differentiation in ASCP did not influence survival in one case series of 38 patients [22] . Some have proposed that presence of any squamous cell carcinoma component in a pancreatic tumor should classify the cancer as adenosquamous [16,26,31] . Prior immunohistochemistry (IHC) analysis on patients with adenosquamous carcinoma have shown the cancer to be positive for cytokeratin (CK) 5/6, CK 7, and p63 and negative for CK 20, p16, and p53 [18,32] .…”

415 Patients With Adenosquamous Carcinoma Of The Pancreas: A Population-Based Analysis Of Prognosis and Survival

“…In our literature search, we identified a total of 307 reported patients with adenosquamous carcinoma of the pancreas. A number of studies examined fewer than 5 patients each with adenosquamous carcinoma [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] . Table 1 (including studies with five or more patients) summarizes the number of patients, tumor location, resection status, and survival reported in previous studies.…”

Surgical outcome of adenosquamous carcinoma of the pancreas

“…The tumors in the 27 cases for which the relevant data was available had a mean size of 4.8 ± 1.8 cm (range, 2-10 cm; Table 1). Preoperative cytological or pathological diagnosis of adenosquamous carcinoma of the pancreas is reportedly rare [12,[16][17][18]21,24,26,30] . However, the two malignant cellular components of adenosquamous carcinoma can be recognized in aspirated smears [17,18,24] .…”

“…Preoperative cytological or pathological diagnosis of adenosquamous carcinoma of the pancreas is reportedly rare [12,[16][17][18]21,24,26,30] . However, the two malignant cellular components of adenosquamous carcinoma can be recognized in aspirated smears [17,18,24] . A careful search for glandular differentiation is warranted when the squamous component predominates, particularly if squamous carcinoma specimens only are obtained by biopsy or fine needle aspiration biopsy [12,16] .…”