3Surgical pathologyExamined all tissues and foreign objects removed from living patientsSpecimens not to be submitted must be written as hospital policyPractice of pathologistsPathological diagnosis : “ Gold standard in medicine ”
4Specimen collection in surgical pathology Incisional biopsy : for diagnostic purposeExcisional biopsy : for diagnostic and therapeutic purposesTissue collection by instruments : needle biopsy, core biopsy, punch biopsy, curettage, shave biopsy, Bard biopsy, endoscopic biopsyNecropsy = biopsy from dead bodyOrgans from operation rooms
5General rules for the biopsy Larger the lesion - more numerous biopsiesUlcerated tumor – recommend peripheral biopsyAvoid necrosis and hemorrhage areasAll fragments must be sent to the pathology departmentNot crushing, squeezing, cauteryImmediately fix in fixativesOrientating specimen e.g. deep margin, superior and inferior margins by using sutured threads (long, short)
6Containers Transparency Lid Leak-proof Wide mouth, flat bottom Size corresponding to specimen volumeLabel
7Fixation of the tissueHard tissues take more time to thoroughly fixed than soft tissue.Penetration rate, around 1 mm./hr. in general (variable, depends on consistency of the tissue).10 times volume of fixative over the specimen volume is needed.
8Fixatives Neutral buffered formalin - fixation time 12-24 hours. Formalin (40% aqueous solution of formaldehyde) - 100mlSodium dihydrogen orthophosphate (monohydrate) - 4gDisodium hydrogen orthophosphate (anhydrous) - 6.5gDistilled water - 900mlThis fixative is suitable for most histological purposes. It is to be preferred to formol-saline (a single 10% solution of formalin in 9% aqueous NaCl) as formalin pigment is avoided. Specimens may be stored in this fluid. The solution is isotonic.
11Filling the request forms (1) 1. identified of the patient2. identified specimen ( gross appearance, cyst, vascular, inking for margin) type of surgery ( biopsy, wide excision) surgical finding3. adequate clinical history (necessary)prior diagnosis, immune status (HIV), prior treatment : radiation, chemotherapy bone lesion : X-ray finding
12Filling the request forms (2) bone lesion : X-ray finding hematolgic disease : CBC, bone marrowfemale reproductive lesion : LMP, hormonehepatitis : LFT 4. Clinical diagnosis or differential diagnosis
19Indications for frozen section Benign or malignant lesionsAdequacy of surgical marginsMetastatic lymph node : sentinel nodes in breast carcinomaPresence or absence of ganglion cells in large intestinal wall of Hirschsprung disease
20Diagnosis of frozen section Benign VS malignant : not specific diagnosisIn case of doubt – wait for permanent section
21Specimens for frozen section Fresh tissue< 1cm. in size is recommended.Put in plastic bag, tightly closed with rubber bandsLabel on the plastic bagPlace the plastic bag in iceSend it to pathology lab immediately
22Inappropriate specimens for frozen section Large tumor or specimensHighly infectious specimens : TB, HIVFollicular lesion of thyroid (can not diffentiate between benign and malignant)
23CytopathologyThe study of individual cells or small clusters of cells for diagnosis and screening of diseases, including cancerspractice of screeners, cytotechnicians, cytopathologists
33Cytogenetics Study structure of chromosome from cell culture FISH in chromosome of leukemiaSpecimensWhole bloodBone marrowAmniotic fluid
34Specimen collection for cytogenetics Sterile techniques2-5 ml. of blood or bone marrow in heparinized tube or sterile heparinized syringe20 ml. of amniotic fluid in sterile disposable syringeSend to lab immidiately (with request form) or keep in refrigerator not more than 12 hours
35Service hours for cytogenetics For blood specimen : Mon, Tue, FriFor Bone marrow : Mon, ThurFor amniotic fluid : TueBlood and bone marrow for FISH : Mon-Fri