Community Case Saeed Awan R5
18 year old presents to ER with history of pain right lower quadrant for three days. Nauseated, denies vomiting and bowel movements normal and no urinary complaint. Admitted in May 2004 with similar pain and improved after overnight observation. Leukocytosis at admission- became normal the next day. Barium follow through was done which was normal.
Case(continued ) On examination tenderness in the RLQ with guarding. Mild Leukocytosis (increased neutro). Ultrasound? Thick walled appendix with fecolith. Diagnosis appendicitis.
Case(continued ) Operative finding Thickened cecum and 8x6 cm mass probably appendix was noted. Difficult dissection and midline laprotomy. Right hemicolectomy performed On opening the specimen it was found to be appendix with a fecolith in the middle. Patient discharged home on fifth postop day.
Case(continued ) Histopathology Carcinoid tumour of appendix with no lymph node involvement.
Carcinoid Tumours Carcinoid tumours describe a range of neoplasms arising from neuroendocrine cells or their precursors. Of intestinal carcinoids, the most common sites are in the midgut, especially the appendix and terminal ileum. Non-intestinal carcinoids include those of the lung, testes and ovary. They are usually of low-grade malignancy. Carcinoid of GI tract arise from enterochromaffin cells(kulchitsky cells) found in the crypts of lieberkuhn. These are pluripotential cells derived from neural crest. Also known as argentaffin cells(staining by silver)
Carcinoid Tumours These tumors were first described by Lubarsh in 1888 In 1907 Oberndorfer Karzinoide (carcinoma like appearance and presumed lack of malignant potential) Male to female ratio is same. Most patients with small bowel carcinoid are in fifth decade of life. Frequent coexistence of second primary malignant neoplasm (10-20%) colon, breast, lung, and stomach. Associated with MEN in 10% cases.
Carcinoid Tumours Intestinal carcinoid Foregut stomach and duodenum Midgut small bowel (28%) appendix (45%) jejunum Hindgut rectum (16%) and colon Extra intestinal carcinoid Bronchial Thymus Testis Ovary Pancreas
Carcinoid Tumours These tumors produce secretory products depending on the location Foregut carcinoid produced low level of serotonin but may secret 5 hydroxytryptophan and ACTH Midgut produces high serotonin production Hindgut rarely produces serotonin but may produce somatostatin and peptide YY.
Carcinoid Syndrome The carcinoid syndrome develops when products, chiefly serotonin, are released by the tumour in large amounts and escape hepatic degradation. Relatively rare disease and occurs in less than 10% of the carcinoid tumor. Common symptoms and signs include flushing (80%) diarrhea (76%) hepatomegaly (71%) asthma (25%) and cardiac lesion i.e right heart valvular disease. The carcinoid syndrome is seen in two situations: Intestinal carcinoids with hepatic metastases The metastases reach sizes several times larger than that of the primary tumour and secrete products into the hepatic vein The vasoactive tumour products are able to enter the systemic circulation Extra-intestinal carcinoids
Symptoms Mostly incidental found at surgery Abdominal pain associated with partial or complete small bowel obstruction Diarrhea and weight loss.
Grossly these tumors are small firm, submucosal nodules that are usually yellow on cut surface. They tend to grow slowly but invasion of serosa, there often is an intense desmoplastic reaction producing meseteric fibrosis, intestinal kinking and intermittent obstruction. Small bowel carcinoid are multicentric in 20-30% of the patients.
Diagnosis Diagnosis elevated urinary levels of 5 hydroxyindoleacetic acid is measured over 24 hours. A plasma concentration of chromogranin A is elevated more than 80% of the patients. Provocative tests using pentragastrin, calcium or epinephrine.
Diagnosis Small bowel carcinoid rarely diagnosed preoperatively. Upper GI and follow through studies may show multiple filling defects such as kinking and fibrosis Ultrasound CT Scan desmoplastic reaction of mesentry, hepatic and lymphnode metastases. 123miBG scan it is mildly radioactive drug that is absorbed by the carcinoid cells. MRI
Treatment Surgical resection is the standard therapeutic modality. Appendiceal carcinoids For tumors smaller than 1.5 cm in greatest diameter that are confined to mucosa, appendicectomy is adequate, with no need for follow-up care. Cure rates are 100%. Tumors 2 cm or larger in diameter are not common but are considered potentially malignant. Consider more aggressive surgery in the form of a right hemicolectomy and lymphadenectomy, similar to that performed for colonic adenocarcinoma. Metastases is rare. Between 1-2 cm carcinoid have 1% metastases and more than 2 cm have 35-50% metastases.
Small bowel carcinoids At laparotomy, perform a thorough examination of the small bowel because multiple lesions are fairly common. Macroscopic tumor size is a fairly good indictor of malignant potential. For tumors smaller than 1 cm in diameter, a local resection is usually adequate. Tumors larger than 1.5 cm have a risk of recurrence, hence the need for a segmental bowel resection with lymphadenectomy. Majority of the tumors (75%) are less than 1 cm and approximately 2% metastases and between 1-2 cm metastases is 50% and more than 2 cm is 80-90%.
Rectal carcinoids Tumor size again is of essence with regard to the extent of resection. Tumors of up to 1 cm in diameter require only local excision or fulguration, with cure rates close to 100% (Mani, 1994). Consider large tumors (>2 cm) malignant, and manage them similar to adenocarcinoma of the rectum, ie, with extensive resection. Tumors of 1-2 cm can be treated either by limited or more aggressive resection, but each case is guided according to the size, invasive nature, and anatomical location. All patients, except for those with lesions smaller than 1 cm, need conscientious follow-up care.
Chemotherapy Response rates are variable but rarely exceed 30%. Results are usually short-lived (ie, <1-y duration). 5-Fluorouracil and streptozocin (Zanosar) based regimens are commonly used in patients with metastatic carcinoid tumors. The value of using newer agents (eg, taxanes, gemcitabine [Gemzar], irinotecan [Camptosar]) is unknown. Chemotherapeutic regimens are only for palliative purposes; they are included in a clinical trial set-up.
Radiation: This only has a palliative role, particularly for painful bony metastasis. Other modalities High doses of sodium iodine-131 labeled metaiodobenzylguanidine, low-dose interferon alfa, and octreotide have all been used, with some reduction in symptoms; however, tumor reduction is rarely observed. When reductions occur, they are only transient (Gordon, 1989; Diaco, 1995). Patients with problematic diarrhea usually find benefit from antidiarrheal medication. Cyproheptadine and histamine-2 receptor blockers may be of benefit because they suppress the production of vasoactive amines or block their peripheral effects.
Metastatic intestinal carcinoid Surgery is considered worthwhile in most cases because this is the best form of palliation regardless of whether the tumor is of the secretory type. Tailor the procedure accordingly, and avoid attempts at major debulking procedures. Obstructive small bowel lesions could be resected (if possible) or by-passed. Multiple liver metastases in patients with carcinoid syndrome are resected, cauterized, or ablated with percutaneous alcohol injections because this usually results in a dramatic relief of symptoms.
Metastatic intestinal carcinoid Hepatic artery ligation or embolization (eg, collagen fibers, gel foam, alcohol) can result in significant tumor necrosis and is of value in patients with bulky, inoperable, or symptomatic liver metastasis, with up to a 60% reduction of tumor bulk in some cases. This form of treatment can be combined with intrahepatic chemotherapeutic infusion. However, it can result in toxic effects, particularly fever, nausea, vomiting, and abdominal pain. Occasionally, the carcinoid symptoms may worsen (Carrasco, 1986).
Prognosis Carcinoid tumors have best prognosis. Resection of carcinoid tumor localized to its primary site approaches 100% survival and 65% 5 yr survival with regional disease and 25-35% among with distant metastases.