Adenosquamous pancreatic cancer producing parathyroid hormone-related protein

Abstract

An autopsy case of adenosquamous pancreatic cancer in a 61-year-old male patient with an elevated serum level of parathyroid hormone-related protein (PTH-rP) is reported. He was admitted to our hospital with a 1-month-long history of abdominal discomfort and progressive abdominal fullness. A computed tomography (CT) scan of the abdomen showed a retroperitoneal mass, approximately 10 cm in diameter, involving the pancreas, with round enhancement on contrast examination. Histological examination of a specimen taken by CT-guided needle biopsy suggested squamous cell carcinoma or transitional cell carcinoma. Laboratory data on admission revealed a high serum calcium level and high PTH-rP level. The calcium level initially responded to intravenous hydration, furosemide, calcitonin, and bisphosphonates, decreasing from 15.0 to 9.0 mg/dl. However, the hypercalcemia recurred after 10 days. The patient developed carcinomatous peritonitis and acute renal failure, and died on the 25th hospital day. Autopsy revealed a mass in the pancreatic body to tail, invading the retroperitoneum, with progressive carcinomatous peritonitis. Histological examination of the mass revealed infiltrating carcinoma, showing squamous differentiation with focal intracytoplasmic lumina formation, consistent with pancreatic adenosquamous carcinoma. Immunohistological examination showed positive staining for PTH-rP. Adenosquamous carcinoma of the pancreas is relatively rare; only a few cases associated with hypercalcemia and for which PTH-rP has been identified as a causative factor have been reported. This is the first case in which immunohistochemistry proved localized PTH-rP in adenosquamous pancreatic cancer cells, associated with persistent hypercalcemia.

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

“…Of note is that malignancy associated hypercalcemia is more commonly associated with squamous cell carcinomas of the head, neck, lung, and esophagus. Case reports have also described patients with adenosquamous pancreatic cancer having elevated levels of calcium due to elevated levels of parathyroid hormone related protein [50,51] . In both reported cases, hypercalcemia persisted despite bisphosphonate treatment [50,51] .…”

“…Other factors such as age, tumor size, differentiation, margin, node status, type of surgery were not shown to affect survival in this case series [16] . Malignancy associated hypercalcemia, which is a rare phenomenon of exocrine pancreatic carcinoma, has been described in ASCP [50,51] . Of note is that malignancy associated hypercalcemia is more commonly associated with squamous cell carcinomas of the head, neck, lung, and esophagus.…”

Hypercalcemia associated with adenosquamous pancreatic carcinoma: a reason to initiate palliative treatment

“…However, in some cases hypercalcemia can recur. These cases have a dismal prognosis heralding imminent death (9,11,12). In our case, medical treatment proved effective.…”

“…To our knowledge, only two cases of adenosquamous pancreatic cancer associated with humoral hypercalcemia in which PTH-rP was identified as the causative factor have been properly reported before (9,10). Our case represents the third in the literature.…”

“…Remarkably the case reported by Inoue and ours showed similar findings: rapid tumor growth in close association with increased calcium levels; in spite that our patient had leukocytosis and severe cachexia at the time of diagnosis. Importantly, in all reported cases (8)(9)(10), hypercalcemia represented an advanced stage of disease and appropriate time to initiate palliative treatment. However, in our case we decided to explore the abdominal cavity because the condition of the patient had greatly improved since admission and the diagnosis was not totally clear.…”