Bread loafing
Encyclopedia
Bread loafing is a common method of processing surgical specimen for histopathology
. The process involves cutting the specimen into 3 or more sections. The cut sections are mounted by embedding in paraffin or frozen medium. The cut edge is then thinly sliced with a microtome
or a cryostat
. The thin slices are then mounted on a glass slide, stained, and covered with another layer of glass.
This method is used to determine surgical margin
for skin tumor
s, and is also known as POMA (Post Operative Margin Assessment as referred to by the National Comprehensive Cancer Network
). It has a higher false negative error rate than CCPDMA
method of tissue processing. The error rate is reduced when the surgical margin
is increased, and the error rate is increased when the surgical margin
is decreased. For this reason, it is not used near the eyelids, and in other cosmetically important areas of the body.
Bread loafing false negative error rate can be reduced by "cutting through the block". Basically, the entire surgical specimen is sliced, and mounted. Even though this method will approach CCPDMA
, frequently, about 1 out of 10 sections are discarded - thus, only 10% of the surgical margin is examined. If the whole "ribbon" was mounted, it would take an inordinate number of glass slides, and not feasible.
Histopathology
Histopathology refers to the microscopic examination of tissue in order to study the manifestations of disease...
. The process involves cutting the specimen into 3 or more sections. The cut sections are mounted by embedding in paraffin or frozen medium. The cut edge is then thinly sliced with a microtome
Microtome
A microtome is a sectioning instrument that allows for the cutting of extremely thin slices of material, known as sections. Microtomes are an important device in microscopy preparation, allowing for the preparation of samples for observation under transmitted light or electron radiation...
or a cryostat
Cryostat
A cryostat is a device used to maintain cold cryogenic temperatures. Low temperatures may be maintained within a cryostat by using various refrigeration methods, most commonly using cryogenic fluid bath such as liquid helium. Hence it is usually assembled into a vessel, similar in construction...
. The thin slices are then mounted on a glass slide, stained, and covered with another layer of glass.
This method is used to determine surgical margin
Surgical margin
Surgical margin, also known as tumor free margin, free margin, normal skin margin, and normal tissue margin, usually refers to the visible normal tissue or skin margin that is removed with the surgical excision of a tumor, growth, or malignancy.-Definition:Surgical margin in a surgery reports...
for skin tumor
Tumor
A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...
s, and is also known as POMA (Post Operative Margin Assessment as referred to by the National Comprehensive Cancer Network
National Comprehensive Cancer Network
National Comprehensive Cancer Network is an alliance of twenty-one cancer centers in the United States, most of which are designated by the National Cancer Institute as comprehensive cancer centers...
). It has a higher false negative error rate than CCPDMA
CCPDMA
CCPDMA is the acronym for "complete circumferential peripheral and deep margin assessment". It is the preferred method for the removal of certain cancers, especially skin cancers.A classical example of CCPDMA is Mohs surgery...
method of tissue processing. The error rate is reduced when the surgical margin
Surgical margin
Surgical margin, also known as tumor free margin, free margin, normal skin margin, and normal tissue margin, usually refers to the visible normal tissue or skin margin that is removed with the surgical excision of a tumor, growth, or malignancy.-Definition:Surgical margin in a surgery reports...
is increased, and the error rate is increased when the surgical margin
Surgical margin
Surgical margin, also known as tumor free margin, free margin, normal skin margin, and normal tissue margin, usually refers to the visible normal tissue or skin margin that is removed with the surgical excision of a tumor, growth, or malignancy.-Definition:Surgical margin in a surgery reports...
is decreased. For this reason, it is not used near the eyelids, and in other cosmetically important areas of the body.
Bread loafing false negative error rate can be reduced by "cutting through the block". Basically, the entire surgical specimen is sliced, and mounted. Even though this method will approach CCPDMA
CCPDMA
CCPDMA is the acronym for "complete circumferential peripheral and deep margin assessment". It is the preferred method for the removal of certain cancers, especially skin cancers.A classical example of CCPDMA is Mohs surgery...
, frequently, about 1 out of 10 sections are discarded - thus, only 10% of the surgical margin is examined. If the whole "ribbon" was mounted, it would take an inordinate number of glass slides, and not feasible.