Histology specimen

Histology specimen

On arrival in the pathology laboratory , specimens receive a unique identification number, usually with a barcode. They proceed to macroscopic assessment and sampling (colloquially - known as ‘cut up’). The largest specimens require initial open - ing (e.g. gastrointestinal tract) or slicing (e.g. uterus, pancreas, breast) to allow further and adequate fixation in formalin, usually over 24–48 hours ( Figure 11.2 ). When fixation is complete and the specimen is in a suitable condition for cutting - and sampling, a pathologist or BMS describes the appearances and lists the method of sampling. Specimens a few millimetres in size such as endoscopic biopsies are suitable for submission in their entirety . Small resections, e.g. skin excision biopsies, may be suitable for slicing into two or more pieces and, again, submission in their entirety . For any specimen that is too large for these approaches, the prosector takes representative samples of areas of interest or relevance ( Figure 11.3 ). This is traditionally the remit of the histopathologist, but BMSs or other non-medical sta ff with specific training increasingly contribute. In the UK and many other countries, there is often adher ence to a regional, national or international guideline that includes a protocol for sampling. For e xample, samples from most types of cancer should include tumour, resection mar gins, lymph nodes, non-neoplastic tissue and any other abnor mal areas. Inks of various colours help to identify resection margins and surfaces during microscope assessment as they remain in place after processing ( Figure 11.4 ). The prosector places specimens, or samples from speci mens, in plastic cassettes ( Figure 11.5 ). BMSs/technical sta ff then embed the tissue in para ffi n wax while in the cassette to produce a tissue block ( Figure 11.6 ). BMSs then cut sections with a thickness of approximately 5 /uni00A0 µm from the block using a microtome ( Figure 11.7 ), place the sections on a glass slide and stain them with haemato xylin and eosin (H&E) ( Figure 11.1 ) . These steps require training and skill. A poor quality sec tion may have various artefacts, such as lines, folds and shatter e ff ect, which impede accurate assessment. H&E remains by far the most common initial stain for his topatholog y assessment, probably because it is inexpensive, safe, fast, reliable, familiar and informative. There is a wider variety of stains for cytolog y preparations including H&E and Giemsa. Traditionally , a pathologist examines stained sections with a microscope ( Figure 11.8 ) and correlates the appearances with the clinical details and the macroscopic description. After special stains, completion of any additional studies such as immunohistochemistry and molecular analysis, the pa thologist enters a report onto a computer system and allocates specific topography and morphology codes that will facilitate future searches. Recent improvements in technology and informa - tion technology (IT) mean that some laboratories use scan - - ning machines to create digital images of the glass slides that pathologists and others can then access locally or remotely at any time (see Digital pathology and artificial intelligence ). - - Summary box 11.3 Histological processing: sequence of events - /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF - /uni25CF /uni25CF /uni25CF - /uni25CF /uni25CF /uni25CF

Figure 11.2 (a) A colon from a patient with familial adenomatous polyposis has been opened longitudinally, and the brown appearance re /f_l ects adequate /f_i xation. Numerous polyps and a carcinoma are apparent. after opening. In this example, there is less /f_i xation, as a result of which the mucosa in the lower part of the picture remains red rather brown. (c) A uterus and an adjacent cystic lesion after slicing to allow /f_i xation (all /f_i gures courtesy of Dr J Chin Aleong, Barts Health NHS Trust, London, UK). (b) An oesophagogastrectomy containing a distal oesophageal tumour than Receipt of specimen Macroscopic (gross) description Sampling of specimen (unless small enough to submit in its entirety) Specimen or samples placed in cassette(s) Production of paraf /f_i n wax block(s) Cutting of 5-µm sections with microtome Sections placed on glass slides Sections stained with H&E Histopathologist examines slides, taking clinical and macroscopic /f_i ndings into account Further studies on tissue, if necessary Entry of report onto computer system Authorisation of report by pathologist

Figure 11.3 A pathologist takes a sample from a resection specimen with a scalpel and forceps. (a) (b) Figure 11.4 (a) An unopened pancreatoduodenectomy specimen (posterior view). Four inks of different colours have been painted onto separate margins and surfaces. (b) Yellow ink on the edge of a histol ogy section (thick arrow). Tumour (thin arrow) lies close to the surface. The pathologist can measure the distance between the tumour and a surface or a resection margin (double-headed arrow). Figure 11.5 A pathologist places a tissue sample from a resection specimen in a cassette. Figure 11.6 Paraf /f_i n wax blocks. Cassettes of different colours allow the organisation of samples and specimens into groups, e.g. accord

ing to specialty or degree of urgency. Figure 11.7 A section (thick arrow) being cut from a paraf /f_i n wax block (thin arrow) with a microtome.

Figure 11.8 A double-headed microscope allows a consultant histo

pathologist and a trainee to view a slide simultaneously.

Frozen section diagnosis is useful when a very rapid answer is necessary . Surgeons are the main users. The surgeon supplies a small representative fresh tissue sample of the area of interest. A BMS freezes the tissue quickly in the pathology laboratory and can produce sections for microscopic examination within several minutes. There are a few disadvantages in comparison with routine processing: fresh tissue carries a higher risk of infection; the quality is inferior to that of routine material, resulting in a potential reduction in diagnostic accuracy and precision; small but representative samples are necessary; certain types of tissue (e.g. fat) are di ffi cult to process; and the process is time-consuming and disruptive ( Summary box 11.4 ). Summary box 11.4 Frozen section: advantages and disadvantages /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF

Advantages Quick diagnosis Disadvantages Poorer quality sections Potential reduction in accuracy and precision of histological diagnosis Labour intensive Disruptive Risk of infection Small sample required Some tissue types dif /f_i cult to process

Histology specimen

On arrival in the pathology laboratory , specimens receive a unique identification number, usually with a barcode. They proceed to macroscopic assessment and sampling (colloquially - known as ‘cut up’). The largest specimens require initial open - ing (e.g. gastrointestinal tract) or slicing (e.g. uterus, pancreas, breast) to allow further and adequate fixation in formalin, usually over 24–48 hours ( Figure 11.2 ). When fixation is complete and the specimen is in a suitable condition for cutting - and sampling, a pathologist or BMS describes the appearances and lists the method of sampling. Specimens a few millimetres in size such as endoscopic biopsies are suitable for submission in their entirety . Small resections, e.g. skin excision biopsies, may be suitable for slicing into two or more pieces and, again, submission in their entirety . For any specimen that is too large for these approaches, the prosector takes representative samples of areas of interest or relevance ( Figure 11.3 ). This is traditionally the remit of the histopathologist, but BMSs or other non-medical sta ff with specific training increasingly contribute. In the UK and many other countries, there is often adher ence to a regional, national or international guideline that includes a protocol for sampling. For e xample, samples from most types of cancer should include tumour, resection mar gins, lymph nodes, non-neoplastic tissue and any other abnor mal areas. Inks of various colours help to identify resection margins and surfaces during microscope assessment as they remain in place after processing ( Figure 11.4 ). The prosector places specimens, or samples from speci mens, in plastic cassettes ( Figure 11.5 ). BMSs/technical sta ff then embed the tissue in para ffi n wax while in the cassette to produce a tissue block ( Figure 11.6 ). BMSs then cut sections with a thickness of approximately 5 /uni00A0 µm from the block using a microtome ( Figure 11.7 ), place the sections on a glass slide and stain them with haemato xylin and eosin (H&E) ( Figure 11.1 ) . These steps require training and skill. A poor quality sec tion may have various artefacts, such as lines, folds and shatter e ff ect, which impede accurate assessment. H&E remains by far the most common initial stain for his topatholog y assessment, probably because it is inexpensive, safe, fast, reliable, familiar and informative. There is a wider variety of stains for cytolog y preparations including H&E and Giemsa. Traditionally , a pathologist examines stained sections with a microscope ( Figure 11.8 ) and correlates the appearances with the clinical details and the macroscopic description. After special stains, completion of any additional studies such as immunohistochemistry and molecular analysis, the pa thologist enters a report onto a computer system and allocates specific topography and morphology codes that will facilitate future searches. Recent improvements in technology and informa - tion technology (IT) mean that some laboratories use scan - - ning machines to create digital images of the glass slides that pathologists and others can then access locally or remotely at any time (see Digital pathology and artificial intelligence ). - - Summary box 11.3 Histological processing: sequence of events - /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF - /uni25CF /uni25CF /uni25CF - /uni25CF /uni25CF /uni25CF

Figure 11.2 (a) A colon from a patient with familial adenomatous polyposis has been opened longitudinally, and the brown appearance re /f_l ects adequate /f_i xation. Numerous polyps and a carcinoma are apparent. after opening. In this example, there is less /f_i xation, as a result of which the mucosa in the lower part of the picture remains red rather brown. (c) A uterus and an adjacent cystic lesion after slicing to allow /f_i xation (all /f_i gures courtesy of Dr J Chin Aleong, Barts Health NHS Trust, London, UK). (b) An oesophagogastrectomy containing a distal oesophageal tumour than Receipt of specimen Macroscopic (gross) description Sampling of specimen (unless small enough to submit in its entirety) Specimen or samples placed in cassette(s) Production of paraf /f_i n wax block(s) Cutting of 5-µm sections with microtome Sections placed on glass slides Sections stained with H&E Histopathologist examines slides, taking clinical and macroscopic /f_i ndings into account Further studies on tissue, if necessary Entry of report onto computer system Authorisation of report by pathologist

Figure 11.3 A pathologist takes a sample from a resection specimen with a scalpel and forceps. (a) (b) Figure 11.4 (a) An unopened pancreatoduodenectomy specimen (posterior view). Four inks of different colours have been painted onto separate margins and surfaces. (b) Yellow ink on the edge of a histol ogy section (thick arrow). Tumour (thin arrow) lies close to the surface. The pathologist can measure the distance between the tumour and a surface or a resection margin (double-headed arrow). Figure 11.5 A pathologist places a tissue sample from a resection specimen in a cassette. Figure 11.6 Paraf /f_i n wax blocks. Cassettes of different colours allow the organisation of samples and specimens into groups, e.g. accord

ing to specialty or degree of urgency. Figure 11.7 A section (thick arrow) being cut from a paraf /f_i n wax block (thin arrow) with a microtome.

Figure 11.8 A double-headed microscope allows a consultant histo

pathologist and a trainee to view a slide simultaneously.

Frozen section diagnosis is useful when a very rapid answer is necessary . Surgeons are the main users. The surgeon supplies a small representative fresh tissue sample of the area of interest. A BMS freezes the tissue quickly in the pathology laboratory and can produce sections for microscopic examination within several minutes. There are a few disadvantages in comparison with routine processing: fresh tissue carries a higher risk of infection; the quality is inferior to that of routine material, resulting in a potential reduction in diagnostic accuracy and precision; small but representative samples are necessary; certain types of tissue (e.g. fat) are di ffi cult to process; and the process is time-consuming and disruptive ( Summary box 11.4 ). Summary box 11.4 Frozen section: advantages and disadvantages /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF

Advantages Quick diagnosis Disadvantages Poorer quality sections Potential reduction in accuracy and precision of histological diagnosis Labour intensive Disruptive Risk of infection Small sample required Some tissue types dif /f_i cult to process

Histology specimen

On arrival in the pathology laboratory , specimens receive a unique identification number, usually with a barcode. They proceed to macroscopic assessment and sampling (colloquially - known as ‘cut up’). The largest specimens require initial open - ing (e.g. gastrointestinal tract) or slicing (e.g. uterus, pancreas, breast) to allow further and adequate fixation in formalin, usually over 24–48 hours ( Figure 11.2 ). When fixation is complete and the specimen is in a suitable condition for cutting - and sampling, a pathologist or BMS describes the appearances and lists the method of sampling. Specimens a few millimetres in size such as endoscopic biopsies are suitable for submission in their entirety . Small resections, e.g. skin excision biopsies, may be suitable for slicing into two or more pieces and, again, submission in their entirety . For any specimen that is too large for these approaches, the prosector takes representative samples of areas of interest or relevance ( Figure 11.3 ). This is traditionally the remit of the histopathologist, but BMSs or other non-medical sta ff with specific training increasingly contribute. In the UK and many other countries, there is often adher ence to a regional, national or international guideline that includes a protocol for sampling. For e xample, samples from most types of cancer should include tumour, resection mar gins, lymph nodes, non-neoplastic tissue and any other abnor mal areas. Inks of various colours help to identify resection margins and surfaces during microscope assessment as they remain in place after processing ( Figure 11.4 ). The prosector places specimens, or samples from speci mens, in plastic cassettes ( Figure 11.5 ). BMSs/technical sta ff then embed the tissue in para ffi n wax while in the cassette to produce a tissue block ( Figure 11.6 ). BMSs then cut sections with a thickness of approximately 5 /uni00A0 µm from the block using a microtome ( Figure 11.7 ), place the sections on a glass slide and stain them with haemato xylin and eosin (H&E) ( Figure 11.1 ) . These steps require training and skill. A poor quality sec tion may have various artefacts, such as lines, folds and shatter e ff ect, which impede accurate assessment. H&E remains by far the most common initial stain for his topatholog y assessment, probably because it is inexpensive, safe, fast, reliable, familiar and informative. There is a wider variety of stains for cytolog y preparations including H&E and Giemsa. Traditionally , a pathologist examines stained sections with a microscope ( Figure 11.8 ) and correlates the appearances with the clinical details and the macroscopic description. After special stains, completion of any additional studies such as immunohistochemistry and molecular analysis, the pa thologist enters a report onto a computer system and allocates specific topography and morphology codes that will facilitate future searches. Recent improvements in technology and informa - tion technology (IT) mean that some laboratories use scan - - ning machines to create digital images of the glass slides that pathologists and others can then access locally or remotely at any time (see Digital pathology and artificial intelligence ). - - Summary box 11.3 Histological processing: sequence of events - /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF - /uni25CF /uni25CF /uni25CF - /uni25CF /uni25CF /uni25CF

Figure 11.2 (a) A colon from a patient with familial adenomatous polyposis has been opened longitudinally, and the brown appearance re /f_l ects adequate /f_i xation. Numerous polyps and a carcinoma are apparent. after opening. In this example, there is less /f_i xation, as a result of which the mucosa in the lower part of the picture remains red rather brown. (c) A uterus and an adjacent cystic lesion after slicing to allow /f_i xation (all /f_i gures courtesy of Dr J Chin Aleong, Barts Health NHS Trust, London, UK). (b) An oesophagogastrectomy containing a distal oesophageal tumour than Receipt of specimen Macroscopic (gross) description Sampling of specimen (unless small enough to submit in its entirety) Specimen or samples placed in cassette(s) Production of paraf /f_i n wax block(s) Cutting of 5-µm sections with microtome Sections placed on glass slides Sections stained with H&E Histopathologist examines slides, taking clinical and macroscopic /f_i ndings into account Further studies on tissue, if necessary Entry of report onto computer system Authorisation of report by pathologist

Figure 11.3 A pathologist takes a sample from a resection specimen with a scalpel and forceps. (a) (b) Figure 11.4 (a) An unopened pancreatoduodenectomy specimen (posterior view). Four inks of different colours have been painted onto separate margins and surfaces. (b) Yellow ink on the edge of a histol ogy section (thick arrow). Tumour (thin arrow) lies close to the surface. The pathologist can measure the distance between the tumour and a surface or a resection margin (double-headed arrow). Figure 11.5 A pathologist places a tissue sample from a resection specimen in a cassette. Figure 11.6 Paraf /f_i n wax blocks. Cassettes of different colours allow the organisation of samples and specimens into groups, e.g. accord

ing to specialty or degree of urgency. Figure 11.7 A section (thick arrow) being cut from a paraf /f_i n wax block (thin arrow) with a microtome.

Figure 11.8 A double-headed microscope allows a consultant histo

pathologist and a trainee to view a slide simultaneously.

Frozen section diagnosis is useful when a very rapid answer is necessary . Surgeons are the main users. The surgeon supplies a small representative fresh tissue sample of the area of interest. A BMS freezes the tissue quickly in the pathology laboratory and can produce sections for microscopic examination within several minutes. There are a few disadvantages in comparison with routine processing: fresh tissue carries a higher risk of infection; the quality is inferior to that of routine material, resulting in a potential reduction in diagnostic accuracy and precision; small but representative samples are necessary; certain types of tissue (e.g. fat) are di ffi cult to process; and the process is time-consuming and disruptive ( Summary box 11.4 ). Summary box 11.4 Frozen section: advantages and disadvantages /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF

Advantages Quick diagnosis Disadvantages Poorer quality sections Potential reduction in accuracy and precision of histological diagnosis Labour intensive Disruptive Risk of infection Small sample required Some tissue types dif /f_i cult to process