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CASE REPORT |
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Year : 2013 | Volume
: 3
| Issue : 2 | Page : 185-188 |
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Primary adenosquamous carcinoma of the pancreas
Mohammad S Iqbal, Aisha Tabassum, Veeragandam Satyanarayana, Mahantappa Shavantagiri
Department of Pathology, Kamineni Institute of Medical Sciences, Narketpally, Andhra Pradesh, India
Date of Web Publication | 13-Dec-2013 |
Correspondence Address: Mohammad S Iqbal Department of Pathology, Kamineni Institute of Medical Sciences, Narketpally - 508 254, Andhra Pradesh India
Source of Support: None, Conflict of Interest: None | Check |
DOI: 10.4103/2278-9596.122983
Adenosquamous carcinoma of the pancreas is a rare subtype of pancreatic cancer. A 55-year-old female patient was admitted in our hospital for evaluation of her epigastric pain of 2 months duration. On physical examination, there was no jaundice. Diffuse tenderness was present over the right upper quadrant and epigastrium. There was a mass located in the epigastrium. Computed tomography scan of the abdomen showed an 8 × 9 cm solid mass with partly cystic areas in the region of body and tail of the pancreas. Other investigations including liver function tests, complete blood count, and urea and electrolytes were normal. A clinical diagnosis of pancreatic tumor was made. Distal pancreatectomy with gastric reconstruction and small bowel anastomosis with splenectomy was done. Histologically, the tumor was diagnosed as adenosquamous carcinoma of the pancreas with infiltration into the wall of duodenum. Adenosquamous carcinoma of the pancreas is an uncommon variant of exocrine pancreatic cancer which demonstrates characteristic immunoprofile and distinct clinical and pathologic features with a worse prognosis than ductal adenocarcinoma. Keywords: Adenosquamous carcinoma, ductal adenocarcinoma, pancreas
How to cite this article: Iqbal MS, Tabassum A, Satyanarayana V, Shavantagiri M. Primary adenosquamous carcinoma of the pancreas. Arch Int Surg 2013;3:185-8 |
Introduction | | |
Adenosquamous carcinoma of the pancreas is a rare aggressive subtype of pancreatic adenocarcinoma with a worse prognosis than the usual type of ductal adenocarcinoma. [1] It is characterized by both ductal adenocarcinoma and squamous cell carcinoma within the same tumor. [1] It has been variously referred to as adenoacanthoma, mixed squamous and adenocarcinoma, and mucoepidermoid carcinoma. [2] Approximately only 150 cases have been reported in the literature. [2] The objective of the present study was to investigate the clinical and morphological features of this rare variant of carcinoma of pancreas with a review of literature.
Case Report | | |
A 55-year-old female was admitted to our hospital because of abdominal pain and weakness. She had epigastric pain of 2 months duration. There was no history suggestive of peptic ulcer or abdominal trauma. On physical examination, she was not jaundiced. Tenderness was present over right upper quadrant. A palpable mass measuring 5 × 5 cm was present in the epigastrium. Further examination of the abdomen did not reveal any abnormality. Computed tomography (CT) scan revealed an 8 × 9 cm pancreatic mass, solid with partly cystic areas present in the body and tail. No central necrosis was evident on CT. The mass was encroaching onto posterior wall of body of the stomach. Calcification in major pancreatic duct was present. There was no evidence of peritoneal or hepatic metastasis. Other investigations including liver function tests, complete blood count, and urea and electrolytes were normal. A diagnosis of pancreatic tumor was made. At operation, there was a tumor on the body and tail of the pancreas. Tumor appeared to be infiltrating the spleen. The liver was normal and there was no ascites. Distal pancreatic resection with splenectomy was performed. The affected wall of stomach along with small bowel at duodenojejunal flexure was also resected and end-to-end anastomosis done. The first postoperative day was uneventful. The patient developed sepsis with circulatory collapse. She died on the third postoperative day probably due to myocardial infarction.
On gross examination, the mass measuring 10 × 7 × 5 cm was present involving the body and tail of pancreas [Figure 1]. It was gray white on cut section and firm in consistency. Normal pancreatic tissue could not be identified on gross examination. A part of posterior wall of body of stomach was seen adherent to the mass. There was also resected small bowel measuring 3 × 2 × 2 cm. Two lymph nodes were isolated. Histological examination revealed a tumor comprising moderately differentiated adenocarcinoma component and well to moderately differentiated squamous cell carcinoma element. The squamous cell carcinoma element comprised more than 30% of the tumor tissue. The adenocarcinoma component was composed of ductal or glandular structures with intracellular or extracellular mucin. Squamous cell carcinoma component was characterized by infiltrative nests and sheets of large polygonal cells with distinct cell margins, intercellular bridges with eosinophilic abundant cytoplasm, and keratinization. Individual cell keratinization was not seen. Both components were seen separated within the substance of the tumor with occasional areas of transition [Figure 2]. Perineural invasion was also evident [Figure 3]. Immunohistochemically, the tumor cells were positive for AE1 and AE3 [Figure 4], and carcinoembryonic antigen (CEA) [Figure 5]. Duodenum showed tumor infiltrating all the layers of wall. Spleen was totally free from the tumor. There was no evidence of tumor in the isolated lymph nodes and peripancreatic fat. It was diagnosed as primary adenosquamous carcinoma of the pancreas. | Figure 2: Histopathology shows glandular adenocarcinoma foci and nests of squamous cell carcinoma (H and E, ×400)
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| Figure 4: AE1/AE3 strong positivity in squamous cell component (AE1/AE3 ×400)
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Discussion | | |
The first report of adenosquamous carcinoma is credited to Herxheimer in 1907. [3] Four theories regarding the histogenesis of adenosquamous carcinoma may be summarized as follows: Adenocarcinoma transforming into squamous cell carcinoma; bipotential undifferentiated cell origin; collision tumor, and squamous metaplasia origin. [3] Pancreatic cancer includes ductal adenosquamous carcinoma, endocrine neoplasm, cystic tumors, solid pseudopapillary tumors, acinar cell carcinoma, adenocarcinoma, squamous cell carcinoma, primary lymphoma of pancreas, and metastatic lesions to the pancreas. [4] Malignant tumors that contain both squamous cell and glandular elements are described in a number of different anatomic sites, including the respiratory tract, gastrointestinal tract, genitourinary tract, pancreaticobiliary tract, salivary glands, and thyroid. [5] Squamous metaplasia of the pancreatic ductal epithelium occurs most commonly in the setting of chronic pancreatitis, but is noted in the adjacent ducts of only about 4% of adenocarcinomas. In our case, we were unable to demonstrate a transition from squamous metaplasia to squamous cell carcinoma. [5]
According to the World Health Organization (WHO) classification, adenosquamous carcinoma is defined as a rare pancreatic neoplasm characterized by the presence of a variable proportion of mucin-producing glandular elements and squamous components. The squamous component should account for at least 30% of the tumor tissue. [6] Our case fulfills this criterion. However, it is still unknown whether the degree of squamous cell differentiation in pancreatic adenosquamous carcinoma is clinically relevant. [7] Similar to the findings in our case, clinically the most common presenting complaint is abdominal pain. [3],[5] Nabae et al. [2] have reported the presence of central necrosis on CT imaging as a feature suggestive of adenosquamous carcinoma, but our case did not show any evidence of necrosis on CT. Similar to our case, Madura et al. [8] reported the tumor location as the body and tail of pancreas in two out of six cases in their study. In our case, pseudoglandular squamous carcinoma or acantholytic pattern was noted, which is a rare finding reported in the literature only by Al Waheeb et al. [1] They also reported the presence of pleomorphic and osteoclastic giant cells which were not seen in our case. Perineural invasion was present, which is widely reported in the literature. [2]
Adenosquamous carcinoma of the pancreas is a rare aggressive tumor with a poor prognosis. The mean prognosis period is about 6 months, which is shorter than for ductal adenocarcinoma of the pancreas. [6] The most involved site is the head of pancreas, followed by the body and tail. [6] In our case, the tumor was present in the body and tail of pancreas. It is worth noting that adenosquamous carcinoma may also present as metastasis to the pancreas, arising from lungs, colon, esophagus, salivary glands, and female reproductive organs. [9] Kardon et al. [5] reviewed 25 cases of adenosquamous carcinoma of the pancreas, all of which showed biphasic malignant components. Most metastases reported in the literature were from the adenocarcinomatous components and not from the squamous component. In our case, local invasion into duodenal and gastric walls was seen. However, no lymph node metastasis was seen. Microscopically spleen was totally normal without any evidence of tumor. Postoperative survival in adenosquamous carcinoma of the pancreas is very short with a mean ± SD survival of 5.04 ± 3.58 months. [8] In the present case, the patient died on the third postoperative day due to myocardial infarction. The incidence of this unusual lesion is really not known, but estimates from review and classification of pancreatic tumors from autopsy and surgically resected specimens have demonstrated it to be approximately 4%. [8]
A number of reports suggest that many of these lesions are large and inoperable; therefore, analysis limited to surgical cases may not be totally indicative of the true incidence since many of these patients have not undergone subsequent surgery or autopsy. Accurate preoperative diagnosis of this lesion is difficult. There are no characteristics on imaging studies to differentiate if from the more common exocrine neoplasms of the pancreas. Once these lesions are identified, with or without accurate preoperative or intraoperative cytologic diagnosis, the question arises as to the extent of treatment and whether aggressive resection should be undertaken. Review of literature shows that there are only five known patients who have survived 1 year or longer, in contrast to the reported series of highly selected patients with invasive ductal carcinomas in whom 5-year survival rates of 20-30% have been reported. In addition, mean survival with or without resection is less than 6 months. [8] One has to consider the risk and complications of major resective surgery in light of this rather short postoperative survival. In the near future, more effective chemotherapy combined with radiation may allow survival with an acceptable quality of life.
Conclusion | | |
Adenosquamous carcinoma of the pancreas is a rare type of exocrine pancreatic tumor which demonstrates characteristic immunoprofile and has distinct clinical and pathologic features, with a worse prognosis than ductal adenocarcinoma.
References | | |
1. | Alwaleeb S, Chetty R. Adenosquamous carcinoma of the pancreas with an acantholytic pattern together with osteoclast-like and pleomorphic giant cells. J Clin Pathol 2005;58:987-90. |
2. | Lampropoulos P, Filippou G, Skafida E, Vasilakaki T, Paschalidis N, Rizos S. Adenosquamous carcinoma of the pancreas,a rare tumor entity: A case report. Cases J 2009;2:9129. [PUBMED] |
3. | Hsu J, Chen H, Wu R, Yeh C, Yeh T, Hwang T, et al. Clinicopathologic features and outcomes following surgery for pancreatic adenosquamous carcinoma. World J Surg Oncol 2008;6:95. |
4. | Na YJ, Shim K, Cho MS, Sung SH, Jung S, Yoo K, et al. Primary adenosquamous cell carcinoma of the pancreas: A case report with a review of the Korean literature. Korean J Intern Med 2011;26:348-51. |
5. | Kardon DE, Thomson LD, Przygodzki RM, Heffess CS. Adenosquamous carcinoma of the pancreas: A clinicopathologic series of 25 cases. Mod Pathol 2001;14:443-51. |
6. | Terada T. Adenosquamous carcinoma and pure squamous cell carcinoma of the pancreas: Report of two cases. Case Rep Gastroenterol 2010;4:369-73. [PUBMED] |
7. | Trikudanthan G, Dasanu CA. Adenosquamous carcinoma of the pancreas: A distinct clinicopathologic entity. South Med J 2010;103:903-10. |
8. | Madura JA, Jarman BT, Doherty MG, Yum M, Howard TJ. Adenosquamous carcinoma of the pancreas. Arch Surg 1999;134:599-603. |
9. | Skafida E, Grammatoglou X, Glava C, Zissis D, Paschalidis N, Katsamagkou E, et al. Adenosquamous carcinoma of the pancreas: A case report. Cases J 2010;3:41. [PUBMED] |
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
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