Radiation Oncology/Pancreas/Squamous Cell


 * Squamous cells not normally present in pancreas, so four theories have been proposed:
 * Metaplasia of pancreatic ductal epithelium present during inflammation (eg during pancreatitis)
 * Pluripotent progenitor cell capable of differentiating to adeno or squamous undergoes malignant transformation
 * Pre-existing adenocarcinoma undergoes transformation to squamous cell
 * Aberrant squamous cell undergoes malignant transformation
 * Reported incidence between 0.005% (pure squamous) and 2% (adenosquamous) tumors of pancreatic tumors
 * 61 cases reported in English literature (PMID 16208119)
 * Mean age 62 years
 * Presenting symptoms: abdominal or back pain, weight loss, anorexia
 * Average tumor size 7.8 cm
 * Equal distribution between head, body and tail
 * Median survival: resected 7 months, non-resectable 3 months
 * Given its rarity, it is important to exclude metastatic disease from elsewhere
 * Enhances on triphasic contrast CT
 * Consider gemcitabine-based chemotherapy

Adenosquamous carcinoma

 * PMID 10367867, 1999 &mdash; "Adenosquamous carcinoma of the pancreas." (Madura JA. Arch Surg. 1999 Jun;134(6):599-603.)
 * Retrospective review of 6 patients
 * Approximately 4% of all pancreatic neoplasms (only 134 cases reported at the time of publication - 1999)
 * Discussion states positive Ca 19-9, ST 439, keratin staining
 * Survival = 5.4 +/- 4 months