Chapter 3 Discussion Questions and Answers

Question 3.1 The process of specimen dissection involves many steps. How would you minimise the risks involved at each of the following levels?

Specimen reception
Staff protection
Waste disposal

Answer

Standard operating procedure in place, robust acceptance criteria, careful matching pot to request form, unique identifier laboratory number, labelling and segregation of high risk specimens, separating similar tissue types, pre-dissection checks of patient identifiers on request form with corresponding pot and numbered cassette
PPPE, staff inoculation, appropriate staff training including Health and Safety, minimise exposure to hazardous chemicals, e.g. downdraft benching, safe clean working environment, careful handling and disposal of sharps, chemical spill kits, working within scope of practice,
Waste management system, segregation of waste into appropriate streams, Licensed waste contractor, HTA issues, respectful disposal, RCPath Retention and storage of pathological records and specimens

Question 3.2 What are the possible consequences of mislabelling a sample?

Answer

Wrong diagnosis given to patient, inappropriate treatment to wrong patient and possibly no treatment to correct patient, medico-legal issue, inappropriate dissection and laboratory investigations on specimen submitted which is dependent on clinical history given

Question 3.3 Macule, papule and keratotic horn are macroscopic terms used to describe skin lesions. Do you understand the terms and can you give examples of benign and malignant conditions which may show these features?

Answer

Macule: flat pigmented area which can have well circumscribed or irregular borders (eg benign examples are junctional naevus, lentigo simplex, flat intradermal naevus, dermatofibroma; Malignant examples are lentigo maligna, melanoma)
Papule: small raised well defined usually smooth nodule (eg benign examples are condyloma, haemangioma, raised intradermal naevus, neurofibroma; malignant examples are BCC, nodular melanoma)
Keratotic horn: hard protrusion made up of keratin arising from an underlying epidermal lesion (eg benign examples are verruca vulgaris [viral wart], actinic keratosis; malignant examples are SCC, keratoacanthoma, Bowen’s disease)

Question 3.4 A 25-year-old male is referred by GP with pilonidal sinus. What is the most common site and how does it arise? Which surgical procedure would you expect to be performed? Do you know the laboratory procedure for dissection and block selection of the specimen? Outline the possible macroscopic and microscopic features.

Answer

Natal cleft most common but also between fingers of hairdressers/barbers/groomers as thought to be caused by loose hairs embedding in skin or broken hair from blocked/ruptured hair follicles. Wide elliptical skin excision including subcutaneous tissue performed, dye can be injected to reveal extent the sinus tract facilitating complete excision where feasible. Check patient demographics and pot match. Examine the specimen noting any features on surface and underlying tissue, look for sinus openings, evidence of tracts opening onto surgical margins. Describe and measure in three dimensions, ink if appropriate, and bread slice perpendicular to the long axis to reveal the full extent of any sinus tract. Select blocks showing any features you described and showing extent of tract, show tract in continuity with any involved surgical margin as this will demonstrate incomplete excision and possibility of re-occurrence +/- abscess formation. Macroscopic findings: sinus openings, tracts, hairs, abscesses. Microscopic features: granulation tissue, hair filled cystic areas, inflammatory cells, foreign body giant cell reaction.

Question 3.5 Request card gives a clinical history of alopecia. Where does the handling of this specimen vary from punch biopsy for diagnosis of actinic keratosis, and explain why?

Answer

Expect to receive two punch biopsy samples for alopecia investigation, one will be dissected in the perpendicular plane (scarring alopecia) while the other is cut in the horizontal plane (for non-scarring alopecia); instructions given to embedders to ensure this orientation adhered to. Sections will be taken at several levels through the embedded blocks. If only one punch received then attempt to bisect and instruct tissue embedders to embed one half for vertical section and other for horizontal sectioning. It is important to view status of hair follicles through the underlying tissue. The punch biopsy for actinic keratosis, like all epidermal lesions, would always be cut in the vertical plane to ensure the epidermis is present and assessable for diagnosis.

Question 3.6 Describe the techniques available to reach a pre-operative diagnosis in a 64-year-old female with a palpable lump in her breast.

Answer

Surgical/radiological technique	Process	Removal of
Cyst aspiration	Drainage of cyst fluid	All or part of cyst fluid. May or may not be sent for analysis depending on appearance and clinical/radiological impression
Fine-needle aspiration	Sample lesional breast cells	Part of lesion for diagnosis
Core biopsy	Needle biopsy (free hand, ultrasound or stereo-guided), normally 3-5 cores	Part of lesion for diagnosis
Vacuum assisted biopsy	Needle biopsy under vacuum, more tissue removed than in core biopsy, so greater sampling achieved	Breast tissue up to 2-3cm, can be diagnostic or therapeutic (excision, for example of a fibroadenoma)
Excision biopsy	Surgical removal of breast tissue <20g for diagnosis and pre-operative diagnosis not possible	All or part of lesion for diagnosis

Question 3.7 A sigmoid colectomy specimen is sent to the laboratory with the clinical details ‘perforated diverticular disease’. What is diverticular disease and what are its complications?

Answer

Diverticular disease can be congenital or acquired. The most common form is acquired diverticular disease. Increased intraluminal pressure leads to the formation of diverticula, which typically form where arteries pierce the muscularis propria, as this is where the colonic wall is weakest.

•Diverticulum: blind pouch leading off the alimentary tract, lined by mucosa that communicates with the intestinal lumen

•Acquired: lack or have attenuated muscularis propria due to focal weakness in wall and increased intraluminal pressure

Note: colonic longitudinal muscularis propria layer is gathered into taeniae coli; focal defects occur where nerves and arterial vasa recta penetrate inner circular muscle wall

Most people with diverticular disease remain asymptomatic, with only up to a quarter becoming symptomatic. Complications include diverticular inflammation (diverticulitis), bleeding, abscess formation, fistula formation, stenosis, adhesions, and rupture with associated peritonitis.