Zheng ZJ, et al: Coexistence of Pancreatic Carcinoma and Pancreatic Tuberculosis: Case Report 537 and a second hypodense mass in the tail of the pancreas. Both masses exhibited peripheral enhancement. No evidence of dila- tion of the bile duct system or pancreatic duct was seen. The hepatic artery was encased by the pancreatic head mass and lymph nodes (Fig. 1). Based on the available data, an initial di- agnosis of pancreatic carcinoma with intrapancreatic metastasis was made. A diagnosis of TB was considered, as it is endemic in China; however, supportive evidence was lacking. The patient presented with no personal or family history of TB, a normal chest X-ray, and none of the typical symptoms of TB. Subse- quently, the patient and his relatives consented to laparotomy. The operation revealed a firm mass in the head of the pan- creas and another mass in the tail of the pancreas, measuring 4.0×3.8×3.5 cm and 1.2×1.0×1.0 cm, respectively. Enlarged lymph nodes were identified along the hepatic artery and hepa- toduodenal ligament. Excisional biopsy of the lymph nodes and fine needle aspiration biopsy (FNAB) of the pancreatic masses were performed. Caseating granulomas with Langhans giant cells were found in the specimens from the lymph nodes and the mass in the pancreatic head, consistent with TB (Fig. 2). Adenocarcinoma was identified in the biopsy specimens taken from the mass in the pancreatic tail. Resection of the distal pan- creas and spleen was then performed. Postoperatively, the histo- pathology on paraffin section confirmed the diagnosis of pan- creatic carcinoma (Fig. 3) and TB. However, the acid-fast stain of the caseous material was negative, and the incisional margin, spleen, and a total of 7 lymph nodes were free of tumor. The pathology report indicated pathologic stage IA (T1N0M0) pan- creatic carcinoma. The patient was treated with isoniazid, rifam- picin, and ethambutol according to the protocol for standard TB chemotherapy. His family members refused anti-tumor chemo- therapy. At the 7-month follow-up, the CT examination showed resolution of the mass in the pancreatic head (Fig. 4). There was no evidence of tumor recurrence or metastasis. DISCUSSION TB is still a common disease in developing countries. With the high prevalence of HIV, it has also been resurgent in devel- oped countries. Pancreatic TB remains a clinical rarity. In India, Bhansali2 found no pancreatic TB in 300 patients with abdomi- nal TB. Auerbach3 reported on 1,656 autopsies with TB; among these cases, 297 (17.9%) had acute generalized TB, but only 14 (4.7%) had pancreatic involvement. Paraf et al.4 identified only 11 (2.1%) cases with pancreatic or peripancreatic involvement in 526 miliary TB cases between 1891 and 1961. The pathogenesis of pancreatic TB has been described: 1) lympho-hematogenous spread from an active focus; 2) direct invasion into adjacent celiac and retroperitoneal lymph nodes; 3) toxic allergic reaction of the pancreas in response to general- ized TB.5,6 The pancreas is biologically resistant to the infection of Mycobacterium tuberculosis . Intraparenchymal injection of M. tuberculosis can cause pancreatic lesions, only if abundant Fig. 3. This histological section demonstrates an appearance consis- tent with moderate differentiated adenocarcinoma (H&E stain, ×50). Fig. 2. Biopsy specimens from the mass of the pancreatic head shows caseating granulomas and Langerhans giant cells (arrow) (H&E stain, ×100). Fig. 4. Follow-up computed tomography scan 7 months later shows resolution of the mass in the pancreatic head.