InsideSurgery Medical Information Blog

Major Depression

February 13th, 2010

Pathophysiology

1) depressed mood daily for a minimum of 14 days 2) not associated with general medical condition or bereavement

Signs and Symptoms

1) diminished pleasure or interest in daily activities 2) sadness, thoughts of death, suicidal ideation 3) irritability 4) feelings of hopelessness or worthlessness 5) insomnia or hypersomnia 6) early morning awakening 7) fatigue 8) weight loss or gain 9) decrease in concentration and/or ability to make decisions

Characteristic Test Findings

Laboratory – 1) decreased plasma tryptophan 2) increased plasma cortisol Radiology – 3) PET scan shows decreased glucose metabolism in caudate nucleus and frontal lobes

Histology/Gross Pathology

decreased noradrenergic neurons in locus ceruleus

Associated Conditions

1) suicide (15%) 2) bipolar disease 3) trauma or assault 4) seasonal affective disorder 5) decreased REM sleep onset (latency)

Biochemistry

1) decreased serotonin levels 2) involvement of prefrontal cortex and basal ganglia in abnormal neurotransmitter functioning

Inheritance/Epidemiology

1) affects 15% of USA population sometime in lifetime 2) female to male, 2:1 3) incidence increases with age 4) 45% concordance rate in identical twins

Treatment

1) selective serotonin reuptake inhibitors (fluoxetine, sertraline, paroxetine) 2) tricyclic antidepressants (nortriptyline) 3) monoamine oxidase inhibitors (no longer first-line treatment owing to hypertensive crisis that arises with ingestion of tyramine-containing substances 4) psychotherapy 5) electroconvulsive therapy in drug-resistant cases

Tips for USMLE

if a 50 year-old woman has lost 25 pounds from “losing her appetite”, reports “feeling like her life has been a waste” and is thinking of suicide, and reports waking up at 4 am each morning without being able to get back to sleep, think depression

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Obsessive Compulsive Disorder

Posted in Surgpedia

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Obsessive-Compulsive Disorder

February 13th, 2010

Pathophysiology

1) compulsive behavior and/or obsessive thoughts that impair everyday functioning 2) usually occurs for at least one hour a day

Signs and Symptoms

1) repetitive handwashing 2) repetitive counting 3) checking repeatedly as to whether a task has been accomplished 4) fear of germs or contamination 5) repetitive hair pulling (trichotillomania) with bald spots or missing eyebrows or lashes 6) wish to conceal their compulsion 7) feeling of anxiety if compulsive behavior is denied 8) tends to have a prolonged and waxing and waning course

Characteristic Test Findings

Radiology – positive PET scan findings in caudate nucleus and frontal white matter (PET scans “light up positive) in areas that have high glucose metabolism)

Histology/Gross Pathology

1) decreased size of caudate nucleus 2) abnormal frontal lobe white matter

Biochemistry

increased glucose metabolism in head of caudate nucleus and orbital cortex of frontal lobes

Associated Conditions

Tourette’s disorder

Inheritance/Epidemiology

1) lifetime prevalence is 2% worldwide 2) onset is usually in early adulthood but adolescent onset does occur 3) more common in males and firstborn 4) familial predisposition does occur with increased concordance in monozygotic twins

Treatment

1) drugs – fluoxetine, fluvoxamine (sometimes in combination with buspirone and benzodiazepine) 2) behavior therapy – with gradual increase in stressors and substitions of less disruptive activity for compulsions

Tips for USMLE

if the patient is a 23 year old man who cannot start work in the morning without washing off the surface of his desk exactly 17 times, think obsessive compulsive disorder

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Panic Disorder

Posted in Surgpedia

Tags: missing eyebrows missing eyelashes positive PET caudate nucleus repetitive checking on task repetitive hair pulling repetitive handwashing trichotillomania

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Non-Hodgkin’s Lymphoma

February 13th, 2010

Pathophysiology

1) a group of 20 conditions all marked by clonal neoplastic transformation of lymphoid cells 2) initial phase involves infiltration of lymph nodes with a variable secondary leukemic phase in which malignant cells circulate in the bloodstream 3) can be either of B cell (90% of patients) or T cell origin 4) classified as low-grade or indolent (small cell or mixed cell), intermediate grade, or high grade (large cell or lymphoblastic)

Signs and Symptoms

1) fever and night sweats 2) painless adenopathy 3) enlarged spleen 4) enlarged liver

Histology/Gross Pathology

1) lymph nodes have a pale color on cut surface 2) obliteration of normal lymph node architecture with white pulp enlargement 3) adults – 40% of patients have a follicular/nodular pattern of lymph node involvement (better prognosis) and 60% have a diffuse pattern 4) children – virtually all patients have the diffuse pattern 5) infiltration of spleen, liver (discrete nodules occur in intermediate and high-grade neoplasms), and bone marrow occurs 6) some children have a “starry sky pattern” of lymph node infiltrate.

Associated Conditions

increased incidence with – 1) organ transplantation 2) HIV/AIDS 3) rheumatoid arthritis 4) sicca syndrome 5) Sjogren’s syndrome 6) Chediak-Higashi disease 7) Wiskott-Aldrich disease 8) ataxia telangiectasia 9) IgA deficiency 10) celiac disease 11) post-treatment for Hodgkin’s disease 12) lupus 13) Klinefelter’s syndrome 14) dioxin exposure 15) treatment with alkylating agents 16) herbicides 17) benzene

Biochemistry

1) Burkitt’s lymphoma – associated with Ebstein-Barr virus 2) follicular small cell cleaved variant – associated wtih bcl-2 gene and translocation of chromosomes 14 and 18 3) mature T cell lymphoma – associated with hypergammaglobulinemia 4) low-grade B cell variant – associated with monoclonal immunoglobulin

Inheritance/Epidemiology

1) increased in frequency in USA in past 50 years 2) slightly more common in men 3) median age of onset is 50 years

Treatment

1) chemotherapy 2) radiation

Tips for USMLE

if question mentions a 68 year-old man with a 2 month history of night sweats, fever, and painless adenopathy in the left axilla, think of a non-Hodgkin’s lymphoma

Related Posts

Non-Hodgkin’s Lymphoma
Burkitt’s Lymphoma
Ataxia-telangiectasia

Posted in Surgpedia

Tags: bcl-2 Burkitt's lymphoma leukemic phase lymph cancer lymphoblastic painless adenopathy starry sky pattern

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Dr. Elizabeth Bellino and Other Physicians Haunted by Grim Reality in Haiti

February 13th, 2010

Tulane pediatrician Dr. Elizabeth Bellino, Massachusetts physician Dr. Laurence Ronan, and others talk about the heartache of watching patients die in front of them.

Posted in Medical News Wire

Tags: Elizabeth Bellino Laurence Ronan Tulane University

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Osteosarcoma

February 13th, 2010

Pathophysiology

1) neoplasm that produces bone (both mineralized and unmineralized) 2) most common in long-bone metaphyses (proximal humerus and tibia and distal femur) 3) metastases are to lung and skeleton

Signs and Symptoms

1) pain and enlargement of affected area 2) fever

Characteristic Test Findings

Radiology – 1) Codman’s triangle (new bone formation at margin of soft tissue) 2) sunburst appearance (spiculations in reactive periosteal tissue) 3) mass lesion with moth-eaten appearance

Histology/Gross Pathology

1) hypervascular, spindle-cell neoplasm 2) main subtypes – fibroblastic, chondroblastic, osteoblastic 3) rarer subtypes – malignant fibrous histiocytosis, telangiectatic, small cell, and epitheliod

Associated Conditions

1) radiation therapy 2) Paget’s disease

Inheritance/Epidemiology

1) 70% occur at age 10-30 years 2) at ages 40-60 occurs as malignant transformation (of Paget’s disease, in radiated tissues) 3) male to female, 2:1

Treatment

preoperative chemotherapy (doxorubicin, ifosfamide, cisplatin), surgical resection (limb-sparing if possible), postoperative chemotherapy

Tips for USMLE

1) osteosarcomas are radiation resistant 2) if Codman’s triangle is mentioned, think osteosarcoma 3) if “sunburst” tumor is mentioned, think osteosarcoma

Posted in Surgpedia

Tags: Codman's triangle malignant fibrous histiocytosis radiation resistant spindle-cell tumor sunburst appearance sunburst tumor

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Ovarian Tumors (Primary)

February 11th, 2010

Pathophysiology

1) neoplastic transformation of the ovaries (can be malignant or benign) 2) classified by cell origin of abnormal growth – epithelial (70%), sex cord stromal (5%-10%), or germ cell (15%-20%) tumors

Signs and Symptoms

1) abdominal pain 2) bloating 3) urinary frequency 4) constipation 5) palpable pelvic mass on gynecologic exam 6) granulosa cell tumor (type of sex cord stromal tumor) causes vaginal bleeding and precocious puberty 7) Sertoli/Leydig cell tumors cause virilization and hirsuitism 8) generally do not become symptomatic until late stage

Characteristic Test Findings

Laboratory – 1) presence of CA-125 tumor marker (occurs in 85% of patients, but very controversial when used as a screening test because other conditions cause increased levels) 2) increased serum levels of alpha fetoprotein (AFP) in germ cell tumors 3) presence of beta-HCG in germ cell tumors 4) increased serum androgens in Sertoli/Leydig cell tumors Radiology – 5) mass on ovary in vaginal and/or abdominal ultrasound

Histology/Gross Pathology

1) epithelial subtypes – serous, mucinous, endometroid, clear cell, Brenner tumors 2) sex cord stromal subtypes – granulosa cell, theca cell, Sertoli’s cell, Leydig’s cell, and collagen-producing tumors 3) germ cell subtypes – teratomas, dysgerminoma, and endodermal sinus (yolk sac) tumors

Associated Conditions

increased incidence with – 1) nulliparity 2) infertility 3) clomiphene use 4) frequent miscarriages 5) family history of ovarian cancer 6) presence of BRCA1 and/or BRCA2 genes 7) Lynch’s syndrome (nonpolyposis colorectal cancer, endometrial cancer, ovarian cancer) 8) oncogenes c-myc, H-ras, K-ras, and neu

Inheritance/Epidemiology

1) 23,000 new cases in USA yearly 2) epithelial and some sex cord stromal tumors (Sertoli/Leydig cell tumors) are unusual before age 40 years 3) germ cell tumors and granulosa and theca cell tumors usually occur before age 30 years

Treatment

Surgery – 1) epithelial and sex cord stromal tumors – TAHBSO, omentectomy, biopsy of pelvic and periaortic nodes, and inspection of paracolic gutters with a “second-look” surgery after chemotherapy 2) germ cell tumors – removal of affected ovary only and no second look surgery Chemotherapy – 3) not for low-grade, stage 1 tumors 4) platinum-based with paclitaxel in epithelial and germ cell tumors; bleomycin-based in sex cord stromal tumors

Tips for USMLE

1) Krukenberg tumors are not primary ovarian tumors but rather metastatic “drop” tumors from the GI tract – classically described as originating in the stomach 2) if a 47 year-old woman who tried fertility drugs for 7 years develops diffuse lower abdominal pain, urinary frequency, and has a palpable mass on bimanual gynecologic exam, think ovarian cancer 3) CA-125 is usually followed post-treatment to see if tumor has recurred 4) germ cell tumors do not generally require removal of both ovaries and uterus, and fertility can be preserved.

Posted in Surgpedia

Tags: AFP alpha fetoprotein Brenner tumor CA-125 dysgerminoma germ cell tumor granulosa cell tumor sex cord stromal tumor theca cell tumor

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Orthopedic Surgeon Dr. John Keeve Discusses His Time on Board USNS Comfort

February 10th, 2010

Dr. John Keeve of Washington state has been operating on severely injured Haitians and says enthusiasm for their work must be tempered by the realization that many patients will lack all semblance of badly needed follow-up care.

Posted in Medical News Wire

Tags: Haiti follow up care

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Astrocytoma

February 10th, 2010

Pathophysiology

1) primary brain tumor dervied from astrocytes 2) wide variation in differentiation – grade 1 (astrocytoma), grade 2 (anaplastic astrocytoma), grade 3 (glioblastoma multiforme)

Signs and Symptoms

1) headaches (especially on waking) 2) vomiting 3) confusion leading to obtundation and coma 4) seizures 5) transtentorial (with fixed and dilated pupils due to CN III damage) or foramen magnum herniation

Characteristic Test Findings

Radiology – 1) poorly demarcated mass on MRI and CT scan 2) grade 3 – often crosses the midline and assumes “butterfly shpae” 3) grade 3 often with hemorrhage and frequent necrosis

Histology/Gross Pathology

Grade 1 – 1) well-differentiated astrocytes with a matrix of thin glial processes; but, grossly, tumor is poorly demarcated 2) occurs in cerebellum and midbrain in children (pilocytic subtype is cystic) and cerebrum in adults 3) some subtypes have Rosenthal’s fivers (thick eosinophilic fibers) Grade 2 – 4) increasing cellular pleomorphism Grade 3 – 5) endothelial cell proliferation in “glomeruloid” pattern 6) marked cellularity 7) serpentine areas of necrosis surrounded by “palisading” cells 8) areas of hemorrhage with red and yellow butterfly tumor

Biochemistry

1) if grade 3 tumors arise de novo, they are associated with a gene defect of amplification of epidermal growth factor receptors 2) if grade 3 tumor arises from a pre-existing grade 1 or 2, it is associated with the p53 or INK4a gene alterations

Inheritance/Epidemiology

1) life expectancy – 5 years for grade 1, 3 years for grade 2, and 9-12 months for grade 3 2) occasionally, the pilocytic subtype of grade 1 tumors can be resected for cure 3) grade 1 tumors mostly occur in children 4) grade 3 tumors are the most common intracranial primary tumor

Treatment

1) surgery for resection for cure (unlikely) or debulking 2) focused external beam radiation 3) sterotactic radiation with gamma knife 4) glucocorticoids 5) chemotherapy with nitrosureas (carmustine, lomustine) 6) many experimental therapy trials are underway with catheter based therapies

Tips for USMLE

1) astrocytomas almost never metastasize outside the CNS 2) if a 76 year old man with no medical problems has been having headaches every morning for the past month, now wakes up acutely confused, and has an MRI that shows a lesion in his frontal lobes in the shape of a butterfly, think glioblastoma multiforme.

Posted in Surgpedia

Tags: brain tumor crossing midline butterfly shaped brain tumor glioblastoma multiforme headache on waking palisading cells Rosenthal fibers

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Pancreatic Cancer (ductal adenocarcinoma)

February 10th, 2010

Pathophysiology

1) development of solid tumor originating from ductal system 2) metastases are most common to liver and regional lymph nodes

Signs and Symptoms

1) abdominal pain (gnawing or burning nature typically) 2) jaundice 3) enlarged, palpable gallbladder in 40% of patients (Courvoisier’s sign) 4) light-colored stools 5) dark urine 6) pruritus 7) weight loss 8) splenomegaly 9) venous thrombosis 10) migratory thrombophlebitis (Trousseau’s sign)

Posted in Surgpedia

Tags: burning abdominal pain Courvoisier's sign palpable gallbladder

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Peutz-Jeghers Syndrome

February 10th, 2010

Pathophysiology

1) inherited disorder marked by numerous GI polyps (usually in small bowel but occasionally from stomach to rectum) and mucocutaneous pigmentation 2) heavy freckles on the face, hands, feet, and perineal areas usually fade at puberty but the buccal (mouth) pigmented spots do not 3) although the polyps are considered benign, 2-3% of patients develop adenocarcinoma in the small bowel

Signs and Symptoms

1) abdominal obstruction 2) intussusception

Histology/Gross Pathology

polyps are hamartomas with smooth muscle and intestinal glands

Associated Conditions

increased risk of – 1) pancreatic cancer 2) breast cancer 3) ovarian cancer 4) endometrial cancer 5) testicular cancer

Biochemistry

affected gene codes for serine threonine kinase

Inheritance/Epidemiology

1) autosomal dominant 2) affected gene is LKB1 on chromosome 19

Treatment

close surveillance for development of adenocarcinoma

Tips for USMLE

1) if question mentions a 10 year-old boy with heavy freckles, including inside his mouth, and his freckles do not fade with age, think Peutz-Jeghers 2) the other common disease with pigmented intraoral lesions is Addison’s disease

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Turcot’s Syndrome

Posted in Surgpedia