Human Anatomy at Colby

Cameron Matticks: JanPlan 2015 Internship talk to Bi265j Human A&P

January 31st, 2015 · Comments Off on Cameron Matticks: JanPlan 2015 Internship talk to Bi265j Human A&P

Cameron Matticks, (’15, Cell & Molecular Biology) was the 2015 Bi265j TA and intern. Listen to his talk to the class about his experience below.

Tags: Guest Speakers · Human Health · Internship Talks

Grand Rounds: 49-Year-Old Male with Adenocarcinoma of the Rectum and Novel Bacterial Therapy

January 29th, 2014 · Comments Off on Grand Rounds: 49-Year-Old Male with Adenocarcinoma of the Rectum and Novel Bacterial Therapy

By: Cameron, Lizzy, & Cody

Adenocarcinoma is cancerous disease that originates in mucus-secreting glandular tissues, most commonly in the lungs, pancreas, prostate, esophagus, colon/rectum. 95% of all colorectal cancers (CRC) are adenocarcinomas. Three months prior to diagnosis, the patient (Male, 49 years) notes blood in his stool. He went to his primary physician who found his physical examination to be normal. His father had colonic polyps, and his paternal grandmother had colon cancer in her 80s. Although family history of CRC is most significant in first degree family members, his father’s history of polyps may suggest a hereditary CRC predisposition in the patient. Six weeks before the patient’s presentation at MGH, he noted decreased stool caliber, and prolonged presence of blood and mucus in his feces. He went to see a gastroenterologist who performed a colonoscopy and discovered an exophytic mass 15 cm from the anal verge and 2 polyps in the descending colon.

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At higher magnification, small infiltrating glands in desmoplastic stroma are diagnostic of moderately differentiated adenocarcinoma. The depth of invasion cannot be assessed from this small biopsy specimen.

Biopsy of the mass revealed dense stroma covered by villiform dysplastic epithelium, with stromal hypertrophy and small infiltrating glands, a characteristic that is indicative of moderately-differentiated adenocarcinoma. An axial CT image of the abdomen/pelvis revealed a rectal mass causing abrupt narrowing of the rectal lumen (3.2×3.1×6.8 cm). An MRI image showed the rectal mass extending through the muscularis propria and into the outer layer (serosa) of the colon. Ultrasonography-guided fine-needle aspiration and core biopsy of the inguinal lymph node determined that the cancer had not spread into the lymph node and was still limited to the colon (although locally advanced). Final diagnosis of the case was moderately differentiated, invasive rectal adenocarcinoma (Stage IIA).

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An axial image from the CT study with oral and intravenous contrast material that was performed at the other hospital  shows a soft-tissue density in the rectum causing abrupt narrowing of the rectal lumen

The patient’s rectal cancer is advanced, and as such the first major treatment decision is whether to resect immediately or use preoperative (neoadjuvant) chemotherapy, radiation, and/or postoperative chemoradiation. The team of doctors recommended preoperative chemoradiation therapy with fluorouracil and radiation therapy. Stage I rectal cancer is often successfully treated with resection, but advanced rectal cancer cases such as Stage II or III typically need multiple treatment modalities (e.g. radiation). Lynch syndrome is an autosomal dominant disorder, and in this case is likely the cause of his colorectal cancer. According to the Amsterdam criteria, this patient did not qualify as having lynch syndrome. However, the Bethesda guidelines, which are more sensitive to subtle cases of Lynch syndrome, did suggest Lynch syndrome. Between 50 and 70% of people with Lynch Syndrome develop colon cancer in their lifetime, and the risk of syndrome is 50% to immediate family members–making clinical diagnosis important not only for the patient but for immediate family members as well. Postoperative treatment was complicated by a Superficial femoral-vein thrombosis which was treated with a 6 month course of heparin. The take down of his ileostomy was successful, with colon function being restored. He is now alive without recurrence more than 4 years after resection, and undergoes annual endoscopic surveillance and visits his doctor biannually.

Scientists at Chonnam National University in South Korea have developed a way to selectively attach flagellar bacteria to polystyrene microbeads. The team modified Salmonella typhimurium with a selectively BSA (bovine serum albumin) pattered PS (polystyrene) microbead. S. typhimurium has been shown to aggregate around quiescent or necrotic tumors due to chemoattraction to tumor cell lysates and spheroids. The attached microbead can release the therapeutic compound inside of the tumor. The bacteria are also useful in detecting metastases and small tumors. One of the most significant challenges of chemotherapeutic treatments is the continuous, specific delivery of optimal quantities of drugs to target cells – which would allow the bacteriobot to shine in efficiency and selectivity of drug delivery. The advancement of this treatment could mean that a total colectomy may not be necessary if the cancer recurs in the colon. The treatment also could help eliminate the negative gastrointestinal issues associated with chemotherapy by reducing general cytotoxicity and negative body response to treatment.


Tags: Grand Rounds