Nicholas Brennan
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Nicholas Brennan has a total of 34 co-authors. Here are the top co-authors by number of shared publications:
- Antonio Manzelli
Hepatobiliary and Pancreatic Surgical Department, Oxford Radcliffe Hospitals NHS Foundation Trust
3 shared publications - Athanasios Petrou
Nicosia Department of Surgery/Div. HPB, 93 Agiou Nikolaou Street, Engomi, 2408, Nicosia, Cyprus
3 shared publications - Alexandros Papalampros
1st Surgical Department, Athens University School of Medicine, "Laiko" General Hospital, Agiou Thoma 17, 11527, Athens, Greece
2 shared publications Athanasios Petrou
2 shared publications- Athanasios Petrou
Dipartimento di Chirurgia, Cattedra di Chirurgia Generale Università Tor Vergata, Direttore Prof. Giuseppe Petrella, Policlinico Tor Vergata, Viale Oxford 81, 00133 Roma, Italia
2 shared publications - Evangelos Felekouras
First Department of Surgery, National and Kapodistrian University of Athens, Laikon General Hospital, 11527 Athens, Greece
2 shared publications
Latest Publications
- 1 October 2012
- Published by International College of Surgeons in International Surgery
- Vol. 97 (2) , 140-144
Hemobilia Due to Cystic Artery Stump Pseudoaneurysm Following Laparoscopic Cholecystectomy: Case Presentation and Literature Review
Hemobilia is the process of bleeding into the biliary tree and is an unusual cause of upper gastrointestinal hemorrhage. When this event results from a cystic artery pseudoaneurysm, it is a particularly rare phenomenon; fewer than 20 cases are described in the literature. Alongside the literature review, we report a case of a 34-year-old woman presenting 3 months post laparoscopic cholecystectomy with hematemesis. Computed tomography (CT) angiography revealed a cystic artery pseudoaneurysm. Following an ineffective hyperselective arterial embolization, the patient was successfully treated by surgical ligation of the right hepatic artery. Even though this complication is uncommon, all surgeons need to be aware of its presentation and of available therapeutic options.
- 1 October 2012
- Published by International College of Surgeons in International Surgery
- Vol. 97 (2) , 140-144
Hemobilia Due to Cystic Artery Stump Pseudoaneurysm Following Laparoscopic Cholecystectomy: Case Presentation and Literature Review
Hemobilia is the process of bleeding into the biliary tree and is an unusual cause of upper gastrointestinal hemorrhage. When this event results from a cystic artery pseudoaneurysm, it is a particularly rare phenomenon; fewer than 20 cases are described in the literature. Alongside the literature review, we report a case of a 34-year-old woman presenting 3 months post laparoscopic cholecystectomy with hematemesis. Computed tomography (CT) angiography revealed a cystic artery pseudoaneurysm. Following an ineffective hyperselective arterial embolization, the patient was successfully treated by surgical ligation of the right hepatic artery. Even though this complication is uncommon, all surgeons need to be aware of its presentation and of available therapeutic options.
- Open Access
- 8 March 2012
- Published by Springer Nature in World Journal of Surgical Oncology
- Vol. 10 (1) , 51
Serous cystadenocarcinoma of the pancreas: report of a case and management reflections
Background: Serous adenomas represent 1-2% of pancreatic neoplasms and typically are asymptomatic not requiring any treatment and simple observation is the option of choice. Although, they carry a realistic risk of malignancy despite the general view that they never become malignant. We report a case, which, according to our best knowledge is the 27th case reported in the literature. Methods: We reviewed the literature by performing a search in Pub Med and Medline. Results: A 86-year old patient known to have a serous cystadenoma of the pancreas treated conservatively through a close clinical and radiological follow up which was unattended for 4 years ending up to our emergency department suffering an acute abdomen. Exploratory laparotomy revealed a perforated prepyloric ulcer which was treated accordingly. Patient died some weeks later due to severe medical co morbidities. Conclusion: Serous cystic neoplasms of the pancreas carry a realistic risk of malignancy despite the general view that they never become malignant. In our opinion the treatment strategy of serous cystic neoplasms of the pancreas should be aggressive even in cases of remote metastases since prognosis of the disease is satisfactory
- 8 March 2012
- Published by Springer Nature in World Journal of Surgical Oncology
- Vol. 10 (1) , 51
Open AccessSerous cystadenocarcinoma of the pancreas: report of a case and management reflections
Background: Serous adenomas represent 1-2% of pancreatic neoplasms and typically are asymptomatic not requiring any treatment and simple observation is the option of choice. Although, they carry a realistic risk of malignancy despite the general view that they never become malignant. We report a case, which, according to our best knowledge is the 27th case reported in the literature. Methods: We reviewed the literature by performing a search in Pub Med and Medline. Results: A 86-year old patient known to have a serous cystadenoma of the pancreas treated conservatively through a close clinical and radiological follow up which was unattended for 4 years ending up to our emergency department suffering an acute abdomen. Exploratory laparotomy revealed a perforated prepyloric ulcer which was treated accordingly. Patient died some weeks later due to severe medical co morbidities. Conclusion: Serous cystic neoplasms of the pancreas carry a realistic risk of malignancy despite the general view that they never become malignant. In our opinion the treatment strategy of serous cystic neoplasms of the pancreas should be aggressive even in cases of remote metastases since prognosis of the disease is satisfactory
- Open Access
- 28 September 2011
- Published by Springer Nature in Journal of Medical Case Reports
- Vol. 5 (1) , 484
Solitary skin metastasis from sarcomatoid carcinoma of the bladder: a case report
Introduction: Cutaneous metastases from carcinomas of the bladder are very rare. They are related to advanced stages of the disease and have poor prognosis with low survival rates. The common treatment modality of cutaneous metastases from a primary bladder cancer is wide local excision followed by chemotherapy. Case presentation: We report a case of solitary skin metastasis from a rare type of urinary bladder carcinoma in a 68 year-old Caucasian man. Urinary bladder carcinoma metastasizing to the skin is an uncommon finding despite the high incidence of this tumor. Skin metastasis generally presents in the late stages of this disease and indicates a poor outcome. Conclusions: Because of the extremely aggressive malignant potential of sarcomatoid carcinomas, the indications for a transurethral resection of the bladder should be carefully assessed and suitable therapeutic strategies should be examined further.
- 28 September 2011
- Published by Springer Nature in Journal of Medical Case Reports
- Vol. 5 (1) , 484
Open AccessSolitary skin metastasis from sarcomatoid carcinoma of the bladder: a case report
Introduction: Cutaneous metastases from carcinomas of the bladder are very rare. They are related to advanced stages of the disease and have poor prognosis with low survival rates. The common treatment modality of cutaneous metastases from a primary bladder cancer is wide local excision followed by chemotherapy. Case presentation: We report a case of solitary skin metastasis from a rare type of urinary bladder carcinoma in a 68 year-old Caucasian man. Urinary bladder carcinoma metastasizing to the skin is an uncommon finding despite the high incidence of this tumor. Skin metastasis generally presents in the late stages of this disease and indicates a poor outcome. Conclusions: Because of the extremely aggressive malignant potential of sarcomatoid carcinomas, the indications for a transurethral resection of the bladder should be carefully assessed and suitable therapeutic strategies should be examined further.
- 6 May 2011
- Vol. 12 (3) , 230-3
Groove pancreatitis. A mini-series report and review of the literature.
Groove pancreatitis is a rare condition characterized by fibrotic inflammation affecting the groove anatomical area between the head of the pancreas, the duodenum and the common bile duct. We report a miniseries of five cases treated surgically in our centre over a period of four years. A review of the literature is also discussed. Patients undergoing pancreaticoduodenectomy over a four-year period were retrospectively reviewed. Patients with a confirmed histological diagnosis of groove pancreatitis were assessed under the headings; patient demographics, presenting symptoms, radiological and histological findings. One-hundred and 60 pancreaticoduodenectomies were performed. Thirty-nine cases demonstrated benign disease and within this, five cases (3.1% of total series; 12.8% of benign cases) were groove pancreatitis. All patients presented with abdominal pain and weight loss, and the majority consumed excess alcohol and were smokers. Radiological findings (CT/MRCP/EUS) revealed duodenal wall thickening in all cases, abnormalities at the head of pancreas and bile duct dilation in four, and cystic changes in the duodenal wall and pancreatic duct dilation in three cases. Groove fibrosis, Brunner's gland hyperplasia and cystic changes in duodenal wall were present in all cases on histological review. All patients reported significant improvement in quality of life at 12 months after surgery. Groove pancreatitis can present in a similar fashion to head of pancreas cancer and chronic pancreatitis. For this reason it is paramount for clinicians to be aware of groove pancreatitis, as this can lead to the correct diagnosis and management of this unique disease.
- 6 May 2011
- Vol. 12 (3) , 230-3
Groove pancreatitis. A mini-series report and review of the literature.
Groove pancreatitis is a rare condition characterized by fibrotic inflammation affecting the groove anatomical area between the head of the pancreas, the duodenum and the common bile duct. We report a miniseries of five cases treated surgically in our centre over a period of four years. A review of the literature is also discussed. Patients undergoing pancreaticoduodenectomy over a four-year period were retrospectively reviewed. Patients with a confirmed histological diagnosis of groove pancreatitis were assessed under the headings; patient demographics, presenting symptoms, radiological and histological findings. One-hundred and 60 pancreaticoduodenectomies were performed. Thirty-nine cases demonstrated benign disease and within this, five cases (3.1% of total series; 12.8% of benign cases) were groove pancreatitis. All patients presented with abdominal pain and weight loss, and the majority consumed excess alcohol and were smokers. Radiological findings (CT/MRCP/EUS) revealed duodenal wall thickening in all cases, abnormalities at the head of pancreas and bile duct dilation in four, and cystic changes in the duodenal wall and pancreatic duct dilation in three cases. Groove fibrosis, Brunner's gland hyperplasia and cystic changes in duodenal wall were present in all cases on histological review. All patients reported significant improvement in quality of life at 12 months after surgery. Groove pancreatitis can present in a similar fashion to head of pancreas cancer and chronic pancreatitis. For this reason it is paramount for clinicians to be aware of groove pancreatitis, as this can lead to the correct diagnosis and management of this unique disease.
- Open Access
- 12 April 2011
- Published by Springer Nature in World Journal of Surgical Oncology
- Vol. 9 (1) , 39
Spontaneous intraperitoneal rupture of pyonephrosis in a patient with unknown kidney carcinosarcoma: a case report
Seventeen cases of peritonitis due to rupture of a pyonephrosis have been reported. The majority of these cases occur secondary to renal stones. Only two cases of ruptured pyonephrosis with concurrent kidney neoplasm have been described and only one of these presented as an acute peritonitis. In this presentation we discuss an unusual case of a 68 year old man with a chronic history of bilateral nephrolithiasis and recent pyonephrosis. He presented acutely with peritonitis and was later found to have a carcinosarcoma of the kidney. The case highlights the importance of recognizing the possibility of underling renal carcinoma in patients presenting with a ruptured pyonephrosis and discuss steps to avoid this serious complication.
- 12 April 2011
- Published by Springer Nature in World Journal of Surgical Oncology
- Vol. 9 (1) , 39
Open AccessSpontaneous intraperitoneal rupture of pyonephrosis in a patient with unknown kidney carcinosarcoma: a case report
Seventeen cases of peritonitis due to rupture of a pyonephrosis have been reported. The majority of these cases occur secondary to renal stones. Only two cases of ruptured pyonephrosis with concurrent kidney neoplasm have been described and only one of these presented as an acute peritonitis. In this presentation we discuss an unusual case of a 68 year old man with a chronic history of bilateral nephrolithiasis and recent pyonephrosis. He presented acutely with peritonitis and was later found to have a carcinosarcoma of the kidney. The case highlights the importance of recognizing the possibility of underling renal carcinoma in patients presenting with a ruptured pyonephrosis and discuss steps to avoid this serious complication.
- 5 January 2011
- Vol. 12 (1) , 50-4
Intraductal papillary mucinous neoplasm (IPMN) and chronic pancreatitis: overlapping pathological entities? Two case reports.
Intraductal papillary mucinous neoplasms (IPMNs) are a recently classified pancreatic neoplasm with an increasing incidence. IPMN is often misdiagnosed as chronic pancreatitis because of symptoms of relapsing abdominal pain, pancreatitis, and steatorrhea and imaging findings of a dilated pancreatic duct of cystic lesions that are frequently confused with pseudocysts. Early recognition of IPMN allows for prompt surgical resection before malignant transformation. We report two cases of patients with long histories of chronic pancreatitis (more than 15 years) that went on to develop IPMN. Both patients presented with symptoms of abdominal pain, nausea, steatorrhoea and eventually weight loss. Biochemical and radiological findings were suggestive of chronic pancreatitis although no clear causes for this were identified. Both patients were followed up with multiple repeat scans with no reported sinister findings. Many years after the initial diagnosis of chronic pancreatitis, radiological investigations identified pathological changes suggestive of neoplastic development and histology confirmed IPMN. The cases demonstrate the ongoing challenges in diagnosing and managing IPMN effectively; highlights the important aspects of epidemiology in differentiating chronic pancreatitis and IPMN; continues the discussion surrounding the relationship between IPMN and chronic pancreatitis.
- 5 January 2011
- Vol. 12 (1) , 50-4
Intraductal papillary mucinous neoplasm (IPMN) and chronic pancreatitis: overlapping pathological entities? Two case reports.
Intraductal papillary mucinous neoplasms (IPMNs) are a recently classified pancreatic neoplasm with an increasing incidence. IPMN is often misdiagnosed as chronic pancreatitis because of symptoms of relapsing abdominal pain, pancreatitis, and steatorrhea and imaging findings of a dilated pancreatic duct of cystic lesions that are frequently confused with pseudocysts. Early recognition of IPMN allows for prompt surgical resection before malignant transformation. We report two cases of patients with long histories of chronic pancreatitis (more than 15 years) that went on to develop IPMN. Both patients presented with symptoms of abdominal pain, nausea, steatorrhoea and eventually weight loss. Biochemical and radiological findings were suggestive of chronic pancreatitis although no clear causes for this were identified. Both patients were followed up with multiple repeat scans with no reported sinister findings. Many years after the initial diagnosis of chronic pancreatitis, radiological investigations identified pathological changes suggestive of neoplastic development and histology confirmed IPMN. The cases demonstrate the ongoing challenges in diagnosing and managing IPMN effectively; highlights the important aspects of epidemiology in differentiating chronic pancreatitis and IPMN; continues the discussion surrounding the relationship between IPMN and chronic pancreatitis.
- Open Access
- 20 December 2010
- Published by Hindawi Limited in HPB Surgery
- Vol. 2010, 1-5
Pleomorphic Giant Cell Carcinoma of the Pancreas with Hepatic Metastases—Initially Presenting as a Benign Serous Cystadenoma: A Case Report and Review of the Literature
Introduction. Pleomorphic giant cell pancreatic cancer is a very rare and aggressive pancreatic neoplasm. A case of pleomorphic giant cell pancreatic cancer presenting as a cystic lesion and in association with a serous cystadenoma presents a unique case which has not been described before. Case Presentation. A 44-year-old alcoholic man presented with abdominal pain, vomiting, and weight loss. Initially, imaging suspected a pancreatic pseudocyst measuring 4.2 cm. Endoscopic ultrasound- (EUS-) guided fine-needle aspiration revealed a serous cystadenoma. With conservative intervention only (fluid resuscitation, analgesia, and antiemetics) the patient improved and was discharged under close observation. Follow-up scan at four months revealed minimal change. Three months later, he was admitted acutely. Repeat scans demonstrated mild cyst enlargement with new liver lesions. Laparoscopic biopsy revealed pleomorphic giant cell carcinoma with the organ of origin the pancreas. Conclusion. This unusual case highlights the challenges in managing pancreatic cystic lesions and emphasizes the importance of considering less common forms of pancreatic cystic masses when the findings are atypical for the presentation. Surgical excision in these cases over conservative steps may be the most appropriate management.
- 20 December 2010
- Published by Hindawi Limited in HPB Surgery
- Vol. 2010, 1-5
Open AccessPleomorphic Giant Cell Carcinoma of the Pancreas with Hepatic Metastases—Initially Presenting as a Benign Serous Cystadenoma: A Case Report and Review of the Literature
Introduction. Pleomorphic giant cell pancreatic cancer is a very rare and aggressive pancreatic neoplasm. A case of pleomorphic giant cell pancreatic cancer presenting as a cystic lesion and in association with a serous cystadenoma presents a unique case which has not been described before. Case Presentation. A 44-year-old alcoholic man presented with abdominal pain, vomiting, and weight loss. Initially, imaging suspected a pancreatic pseudocyst measuring 4.2 cm. Endoscopic ultrasound- (EUS-) guided fine-needle aspiration revealed a serous cystadenoma. With conservative intervention only (fluid resuscitation, analgesia, and antiemetics) the patient improved and was discharged under close observation. Follow-up scan at four months revealed minimal change. Three months later, he was admitted acutely. Repeat scans demonstrated mild cyst enlargement with new liver lesions. Laparoscopic biopsy revealed pleomorphic giant cell carcinoma with the organ of origin the pancreas. Conclusion. This unusual case highlights the challenges in managing pancreatic cystic lesions and emphasizes the importance of considering less common forms of pancreatic cystic masses when the findings are atypical for the presentation. Surgical excision in these cases over conservative steps may be the most appropriate management.
- Open Access
- 14 October 2010
- Published by Springer Nature in World Journal of Surgical Oncology
- Vol. 8 (1) , 90
GIST suture-line recurrence at a gastrojejunal anastomosis 8 years after gastrectomy: can GIST ever be described as truly benign? A case report
We present the case of a 71 year old man with recurrence of a Gastro Intestinal Stromal Tumour (GIST) at the gastrojejunal anastomosis eight years following partial gastrectomy for a very small primary gastric GIST. He presented acutely on both occasions with haemodynamic shock secondary to massive haematemesis. During his initial presentation in 2001, an emergency laparotomy was performed, demonstrating a pre-pyloric ulcerative lesion. The histopathology was in keeping with a diagnosis of a gastric GIST with a < 2 cm tumour, with <5 mitosis per 50/HPF, no signs of necrosis and invasion limited to the mucosa. Eight years later the same patient presented with a similar clinical picture of haemodynamic instability secondary to haematemesis. Emergency endoscopy showed an irregularly shaped elevated lesion on the gastrojejunostomy line suggestive of recurrence. He subsequently underwent completion gastrectomy and the histology revealed a 0.8 cm GIST tumour composed of spindle cells with <5 mitosis per 50/HPF, tumor invasion into the submucosa and positive expression of c-kit and SMA. The patient remains recurrence free 18 months post surgery. The literature suggests that tumour size, mitotic rate and tumour site are the most important predictive factors of recurrence. Additional features such as the presence of necrosis, local tumour invasion and positive resection margins, can also influence recurrence rates. In this case the lesion was a gastric GIST, very small (<2 cm), had low proliferation rate (<5 mitosis/HPF), lacked necrosis and was limited to the mucosa. Recurrence of such a primary GIST at the anastomotic line, eight years after initial resection has never been demonstrated among review of several thousand primary GISTs. This case highlights how even the most innocent GISTs can never be described as truly benign.
- 14 October 2010
- Published by Springer Nature in World Journal of Surgical Oncology
- Vol. 8 (1) , 90
Open AccessGIST suture-line recurrence at a gastrojejunal anastomosis 8 years after gastrectomy: can GIST ever be described as truly benign? A case report
We present the case of a 71 year old man with recurrence of a Gastro Intestinal Stromal Tumour (GIST) at the gastrojejunal anastomosis eight years following partial gastrectomy for a very small primary gastric GIST. He presented acutely on both occasions with haemodynamic shock secondary to massive haematemesis. During his initial presentation in 2001, an emergency laparotomy was performed, demonstrating a pre-pyloric ulcerative lesion. The histopathology was in keeping with a diagnosis of a gastric GIST with a < 2 cm tumour, with <5 mitosis per 50/HPF, no signs of necrosis and invasion limited to the mucosa. Eight years later the same patient presented with a similar clinical picture of haemodynamic instability secondary to haematemesis. Emergency endoscopy showed an irregularly shaped elevated lesion on the gastrojejunostomy line suggestive of recurrence. He subsequently underwent completion gastrectomy and the histology revealed a 0.8 cm GIST tumour composed of spindle cells with <5 mitosis per 50/HPF, tumor invasion into the submucosa and positive expression of c-kit and SMA. The patient remains recurrence free 18 months post surgery. The literature suggests that tumour size, mitotic rate and tumour site are the most important predictive factors of recurrence. Additional features such as the presence of necrosis, local tumour invasion and positive resection margins, can also influence recurrence rates. In this case the lesion was a gastric GIST, very small (<2 cm), had low proliferation rate (<5 mitosis/HPF), lacked necrosis and was limited to the mucosa. Recurrence of such a primary GIST at the anastomotic line, eight years after initial resection has never been demonstrated among review of several thousand primary GISTs. This case highlights how even the most innocent GISTs can never be described as truly benign.