PSU Volume 48 No 01 JANUARY 2017

Retroperitoneal Sarcomas

Renal Cell Carcinoma

Incisional Hernias

PSU Volume 48 NO 02 FEBRUARY 2017

Barrett Metaplasia in Esophageal Atresia

Intrapericardial Teratoma

Tumors of the heart and pericardium are rare causing a variety of cardiac and systemic symptoms depending on the size and anatomic location. Growth rate, friability and ability to invasiveness can determine clinical features and outcome. Intrapericardial teratoma is a very rare congenital tumor which can be diagnosed in-utero or soon after birth due to its association with massive pericardial effusion. Intrapericardial teratoma is a germ cell origin tumor composed of the three primitive germ layers, namely endoderm (gastric and intestinal mucosa), ectoderm (neuroglia) and mesoderm (bone, cartilage, fatty or fibrous tissue) arising from the pericardium. Patient age ranges from intrauterine life to adulthood with most cases occurring in infants. More than 75% of intrapericardial teratomas occur in children under the age of fifteen. Main clinical symptoms include respiratory distress, pericardial tamponade and cyanosis. Most are mature type teratomas followed by immature cases. They can be diagnosed intrauterine using prenatal ultrasound with findings of a large pericardial effusion and intrapericardial multilobulated and cystic mass with calcifications. Diagnosis is confirmed using MRI and fetal echocardiogram. In cases of fetal cardiac tamponade or hydrops intrauterine pericardiocentesis can be performed to permit near full-term birth. Intrapericardial teratomas are usually located in the right side of the heart causing displacement and left-side rotation. The arterial supply is from a pedicle to one of the great vessels or directly from the aorta.  Surgical excision is the only effective management for intrapericardial teratoma. Since most tumors are benign the prognosis is usually good after resection. The presence of immature neuroepithelium carries a poor prognosis needing adjuvant radio- and chemotherapy. Surgical resection of the teratoma in the fetus through EXIT strategy or open fetal surgery is feasible if the tumor is growing fast and causing significant hemodynamic changes including hydrops or impending death.

Tubo-ovarian Abscess

Tube-ovarian abscess (TOA) is a well known complication of pelvic inflammatory disease (PID) in young sexually-active women during reproductive years, including adolescents. TOA is an ascending infection from the cervix and/or vagina through the uterus to the fallopian tubes and ovaries. The infection is usually the result of sexually transmitted disease or after instrumentation of the female genital tract. Patients with TOA usually present with low abdominal/pelvic  pain, vomiting and fever. Pelvic examination shows adnexal mass or tenderness. White blood cell count is elevated. The diagnosis is made with the help of US, CT-Scan or MRI. In occasion the diagnosis cannot be separated from symptoms of appendicitis. Appropriate management of PID complicated with a tubo-ovarian abscess requires prompt initiation of empiric broad spectrum antibiotics effective against both Neisseria gonorrhea and Chlamydia trachomatis. In the majority of patient antibiotics is all the treatment that is needed. At least 24 hours of inpatient observation is recommended during therapy. It is estimated that almost 40% of women with TOA fail to respond within 48-72 hours of therapy needing drainage of the abscess either percutaneously or via laparoscopic approach. PID and TOA are extremely rare in non-sexually active or amenorrheic adolescent females. The etiology in such cases includes inflammatory bowel disease with hematogenous seeding of bacteria, recurrent urinary tract infection with urinary vaginal reflux, poor hygiene, obesity with vulvar adiposity and müllerian abnormalities. The organism most commonly identified in such cases of virginal adolescents is Escherichia Coli, alpha hemolytic streptococcus and Pasteurella multocida. Though most cases of TOA are due to PID, laparoscopy can elucidate the correct diagnosis in atypical cases such as virgins, postmenopausal or those that do not respond to antibiotherapy.

PSU Volume 48 No 03 MARCH 2017

Petersen Hernia

Petersen hernia (PH) is a specific type of internal hernia where the small bowel migrates into the space between the caudal surface of the transverse mesocolon and the mesentery of the gastrojejunostomy limbs when either open or laparoscopic Roux-en-Y gastric bypass are performed for morbid obesity and biliopancreatic diversion. Clinical presentation is characterized by nonspecific symptoms of bowel obstruction such as postprandial abdominal pain, nausea and vomiting leading to delayed diagnosis and producing small bowel ischemia and even death. Some patients may have recurrent transient herniation and intermittent abdominal pain. The Petersen's space was initially described in 1900 as a space between the Roux limb and the transverse mesocolon formed after gastrectomy with Roux-en-Y reconstruction. Body weight loss is considered to be a risk factor for an internal hernia to develop. A greater loss of weight such as it occurs in bariatric surgery can induce an increase in the size of Petersen defect increasing the risk of an internal hernia. Antecolic reconstruction procedures may tend to specifically lead to Petersen hernia. Three types of Petersen hernia have been described: Type A involves the alimentary (Roux) limb, Type B involves the bilio-pancreatic limb and Type C involves the common channel.  The diagnosis of Petersen hernia is confirmed using oral and intravenous contrast CT-Scan with findings of whirl sign, target sign, small bowel obstruction, clustered loop, retraction of the mesentery, congestion of mesenteric fat and vessels, mushroom sign, hurricane sign, small bowel behind SMA and right-sided anastomosis. The whirl signs of mesenteric fat or vessels have been reported to be the best single predictors of Petersen hernia with sensitivity of 80% and specificity of 90%. A high index of suspicion should be maintained to diagnose a Petersen hernia. Management is surgical reduction of the internal hernia on an emergency basis.

Multiple Intestinal Atresias

First Branchial Cleft Anomaly

PSU Volume 48 No 05 MAY 2017

Intrathyroidal Schwannoma

Benign nonepithelial tumors of the thyroid gland are very rare lesions in children and adults. They include lesions such as vascular tumors, smooth muscle tumors and tumors of nerve origin. Primary Schwannoma, also known as neurilemmoma, of the thyroid gland was first reported in 1964 with most cases seen in the adult population. Schwannomas are peripheral nerve tumors originating from neuronal sheath cells (Schwann cells). They mostly occur in the 40 to 60 years old age groups without sex predilection. They are benign tumors that can be found anywhere in the body with half of them originating in the head and neck region. Neurilemmomas of the neck region arise from the cranial nerves with the vagus nerve or its branches being the most frequently affected followed by the cervical sympathetic chain. In the thyroid gland they arise from the sensory nerves or from autonomic innervation of the gland.  Half of all reported cases of intrathyroidal Schwannomas come from Asia. The clinical presentation of a intrathyroidal schwannoma is a typical palpable non-tender thyroid nodule. Thyroid function tests are within normal limits. They have a slow but progressive growth causing compression of vital structures of the neck. Thyroid scintigraphy demonstrates a cold area within the affected lobe. Ultrasound describes a well-delineated, solid or predominantly solid tumor of low echogenicity with variable cystic degeneration. Fine needle aspiration biopsy of the tumor is diagnostic of the histologic nature of the mass. Two growth patterns are seen within the lesion: a predominantly cellular area composed of spindle-shaped Schwann cells with little stromal matrix (Antoni A type tumor), and a less cellular myxoid area with microcyst formation (Antoni type B tumor). On immunohistochemistry Schwannomas are positive for S100 and Vimentin, and negative for Desmin and SMA. Management of intrathyroidal Schwannomas is either enucleation or total thyroid lobectomy. Intrathyroidal Schwannomas are associated with an excellent prognosis once completely removed. 

Glucagonoma

Glucagonoma is a rare neoplasm of the pancreatic neuroendocrine islet alpha-cells where they secrete abundant glucagon occurring in one of every 20 million individuals. Glucagonoma tumors excessive secretion of proglucagon-derived peptides is clinically characterized by a necrolytic migratory erythema (NME), diabetes mellitus, weight loss, anemia, painful glossitis, stomatitis, thromboembolic complications, dilated cardiomyopathy and neuropsychiatric disturbances. Vast majority of glucagonomas are sporadic and occurs in adults. Children with MEN type 1 can harbor this tumor. Median time between onset of symptoms and diagnosis is 3-4 years. Glucagon hypersecretion increase hepatic glucose output antagonizing the effect of insulin and causing Diabetes. Also it exerts a catabolic role attenuating protein synthesis. Glucagonoma syndrome is the triad of glucagon-secreting tumor, diabetes and NME. The NME is the most specific manifestation of glucagonoma with early recognition leading to a rapid diagnosis of the presence of a glucagon-producing tumor. NME distributed in the groin, perineum and distal extremity is characterized by an annular pattern of erythema and centrally formed fragile vesicles, bullae and crusts present in 70% of patient with glucagonoma. Glucagonoma is a slow growing and low malignancy tumor. Metastasis represent the main prognostic factor for glucagonoma with 100% survival in cases without metastasis.  Metastasis occur to the liver and peripancreatic lymph nodes. Somatostatin analog therapy may be useful in relieving glucagonoma syndrome by inhibiting glucagon secretion and counteracting its effect. CT-Scan is the diagnostic modality to diagnosed a glucagon producing tumor of the pancreas. Glucagonoma typically occurs in the distal pancreas. Fasting glucagon levels are elevated. Complete resection of the primary pancreatic tumor and limiting metastasis, including liver transplantation, is the only chance of cure.   

Vipoma

Vipoma is a very rare malignant neuroendocrine tumor. Most Vipomas arise in the pancreas with 10% of them arising from other tissues of neural crest origin of the body. In children a ganglioneuroblastoma can behave as a Vipoma. Most neurogenic tumors associated with the Vipoma syndrome have been found in children. Vipomas secrete vasoactive intestinal peptide (VIP), a hormone which stimulates adenosines 3',5'-cyclic phosphate (cAMP) production by the intestinal tract causing watery diarrhea, hypokalemia, hypophosphatemia, hypomagnesemia, hyperchloremic metabolic acidosis from severe intestinal loss of bicarbonate and achlorydia syndrome due to inhibition of gastric acid production. Occasionally hypercalcemia due to release of PTH by the tumor, glucose intolerance and hypotension can occur. With the diarrhea the patient can develop  flushing similarly to the carcinoid syndrome. Majority of Vipomas are sporadic cases and 50-60% have metastasized by the time the diagnosis is made. VIP is elevated in all cases of Vipomas and can be measured in blood. Diagnosis can be confirmed using imaging such as US, CT-Scan (hyperattenuating lesion in the arterial phase that becomes inconspicuous in the venous phase), MRI, Somatostatin-receptor scintigraphy or PET-Scan. Vipomas appear as well-defined homogenous mass with central necrosis and hypervascularized. Most Vipomas tumors in the pancreas occur in the tail. Surgical extirpation is the mainstay of treatment of Vipomas. If a tumor has been identified, complete surgical excision is the primary form of treatment. If the tumor cannot be removed completely surgical debulking may have a palliative effect. Medical therapy with somatostatin analogue can be used for symptomatic relieve in cases of inability to remove the tumor completely. Others alternatives include peptide receptor radionuclide therapy, streptotozin chemotherapy, ablation, hepatic artery embolization or liver transplant.     

PSU Volume 48 NO 06 JUNE 2017

Epigastric Artery Flap Extremity Reconstruction

Recurrent Achalasia after Esophagomyotomy

Achalasia is the most common motility disorder of the esophagus causing dysphagia due to loss of primary esophageal peristalsis and impaired relaxation of the lower esophageal sphincter (LES). Balloon dilatation and Botox injection are considered short-lived method of managing achalasia. Effective long-term management of achalasia results with laparoscopic Heller esophagomyotomy and Dor partial fundoplication. Factors known before the procedure such as patient characteristic, degree of esophageal dilatation or tortuosity, manometry findings and prior treatments have little effect on long-term outcome. Common causes of surgical failure are gastroesophageal reflux and recurrent dysphagia. When dysphagia occurs after myotomy is more often recurrent than persistent. Changes in the esophagus and/or LES that develops after the operation is more important in defining recurrence of symptoms. Almost 25% of all patients still experience dysphagia once per week after surgery. It is believed obstructive scar tissue or distortion of the myotomy develop in theses cases. The only predictor of the need for postop dilation is history of preop dilation. Specific causes of recurrent achalasia after surgery include: 1- Incomplete myotomy or scarring of the distal edge of the myotomy. Longer and more separated myotomy reduces this problem; 2- Not performing a fundoplication. This causes abnormal symptoms of reflux and heartburn. A 360-degree fundoplication aggravates dysphagia. Partial fundoplication prevents reflux and does not impair esophageal emptying; 3- GE reflux is considered a common cause of recurrent dysphagia due to esophagitis, scarring and development of Barrett's esophagus; 4- the effects of previous treatment due to scar tissue created from endoscopic manipulation or Botox injections; 5- Esophageal cancer since achalasia patients are at increased risk of developing squamous cell carcinoma. Diagnostic evaluation of recurrent symptoms must include: barium swallow, upper endoscopy and manometry. Management of recurrent achalasia include pneumatic balloon dilatation, revisional surgery, POEM or esophagectomy.  

Nontuberculous Mycobacteria Lymphadenitis

Atypical mycobacteria, also known as nontuberculous mycobacteria (NTM) are acid-fast bacteria other than Mycobacterium tuberculosis. Nontuberculous mycobacteria can cause difficult to diagnosed lymphadenitis in immunocompetent children. Exposure of the human oral cavity and respiratory tract to NTM comes from soil, specially after putting wet dirt or soil into their mouths. Incubation periods are variable but can reach five years in some cases. A diagnosis of NTM lymphadenitis should be suspected in children less than five years of age, female predominance, with subacute, unilateral, non-tender cervicofacial lymphadenitis resistant to standard antibiotic therapy. Submandibular and anterior cervical lymph are most commonly involved. Diagnosis is established by acid-fast staining, mycobacterial culture and histopathology. Sampling method for diagnosis includes FNA aspiration, curettage, drainage or complete excision. Polymerase-chain reaction testing of lymph node material has the highest diagnostic yield, followed by mycobacterial culture and microscopy for acid-fast bacilli. Positive culture will confirm the diagnosis but it can take six weeks. Growth characteristic of NTM lymphadenitis include slow-growing (M Fortuitum, Chelonei and Abscessus) and fast-growing mycobacteria (M. Marinum, Kansasii, Avium-intracellulare). In the US the majority of NTM lymphadenitis in children are caused by M Avium complex. A PPD skin test might be positive. The course of NTM lymphadenitis might be variable and involve eruption of the lymph node and tract formation with drainage; the lymph node might also remain indurated. Systemic symptoms are unusual in immunocompetent children. Reactivation of NTM can occur after trauma or injury near the affected area. Management of NTM lymphadenitis includes surgical (complete resection is gold standard if technically feasible), less likely prolonged antimycobacterial oral therapy (Clarithromycin is preferred).