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| Journal of the New Zealand Medical Association,
05-November-2010, Vol 123 No 1325
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The pathology request form is a crucial communication
document between treating physician and
histopathologist.1 The data set should include
demographics (age and sex of patient), site and type of specimen, clinical
history and preferably the diagnostic query the treating physicians wants
answered by the pathologist.
Anecdotal evidence suggests that the information routinely
captured on the pathology request form is often minimal, thereby affecting the
ability of the histopathologist to correctly report the
specimen.2–6
In addition, the recent Australasian / New Zealand Melanoma
guidelines recommend that the optimal biopsy approach for a pigmented skin
lesion suspicious of melanoma is complete excision with a 2 mm margin, as
partial biopsies may not be fully representative of the
lesion.6 They do however, go on to comment,
“Incisional, punch or shave biopsies may be appropriate in carefully
selected clinical circumstances, for example, for large facial or acral lesions,
or where the suspicion of melanoma is low.”
This study aimed to assess the quality of information
available to the pathologist from the histology request forms, the accuracy of
the preliminary clinical diagnosis, and the appropriateness of the biopsy sample
provided.
MethodsThe histology request forms of skin lesions, read by a
single pathologist over a 4-week period, were prospectively assessed for the
quality of information. Particulars assessed included demographic data (age and
sex of patient), body site of specimen, nature of specimen and all clinical
information included on the form.
The histopathologist graded each request form as to
whether it contained enough information to determine the purpose of the
procedure (was it diagnostic or therapeutic), the type of sample provided
(whether curettage, shave, punch or excision), the anatomical site, and whether
the specimen was thought to potentially be a melanoma, a pigmented lesion, a
non-melanoma skin cancer, or some other skin lesion. The histopathological
diagnosis was then compared to the preliminary clinical diagnosis. The
suitability of the specimen was also determined according to the clinical and
histological diagnosis.
ResultsOver a 4-week period during October/November 2009, 375 skin
specimens were received. These were from 196 women and 179 men, with a mean age
of 58.4 years (SD 16.4 yrs, range 6 - 105 yrs). The majority of the skin
specimens had been taken in the primary care setting (317 lesions, 84.5%), with
the remainder by plastic surgeons (43 lesions, 11.5%), dermatologists (eight
lesions, 2%) and ‘other’ specialist surgeons (seven lesions,
2%).
The face was the most common site (92 lesions) followed by
the back (66), trunk (62), legs (59), arms (58) and neck (28). In 10 instances,
body site of the specimen was not specified. The majority of specimens were
removed by excision (233 lesions, 62%), with 57 (15%) lesions removed by shave
and three by curettage (Table 1). Seventy-six (20%) lesions were punch biopsies
and six were incisional diagnostic biopsies. Eighty-one specimens (22%) were
marked as being diagnostic, 74 (20%) therapeutic, with the majority not
specified (220, 59%).
Table 1. Type of biopsy with number of
specimens inadequate to make a histological diagnosis
From the request form, the histopathologist concluded that
the referring doctor thought 123 (33%) lesions might be a non-melanoma skin
cancer, 77 (20.5%) a pigmented lesion, 27 (7%) a melanoma with 42 (11%) other
types of skin lesions. In 106 (28%) lesions, it was not possible to determine
what the referring practitioners thought the lesion might be.
The most common clinical diagnoses offered were basal cell
carcinoma (54 cases), naevus (48), squamous cell carcinoma or keratoacanthoma
(47), seborrhoeic keratosis (15), and melanoma (12) (Table 2). The clinical
diagnosis was either not specified in 56 cases (15%), or simply labelled as
‘lesion’ in 84 (22%) patients. Therefore in 140/375 cases (37%), no
useful clinical information was available to the pathologist.
Table 2. Clinical diagnosis with number (%)
confirmed by histology
The clinical diagnosis matched the histopathological
diagnosis in 145 cases (39%) (Table 3). Of the 230 (61%) cases where the
clinical diagnosis (or lack of one) did not match the histological diagnosis, in
136 instances (36%) this was not considered clinically significant. Examples
include a histological diagnosed seborrhoeic keratosis having been diagnosed
clinically as a benign naevus, or a squamous cell carcinoma having been
diagnosed as a basal cell carcinoma. Sixty percent (78/131) of histologically
confirmed malignant lesions had not been identified on the request form as being
malignant: only two of 12 (17%) melanomas, 33 of 74 (45%) BCCs and 18 of 45 SCCs
(57%) were diagnosed clinically.
Table 3. Histological diagnosis with number (%)
of patients diagnosed clinically
The specimen and/or request form were considered inadequate
to make a histopathological diagnosis in 25 cases (6.7%) (Table 1).
There were 82 punch and incisional biopsies; of these there
were no clinical details in 23% and in a further 22%, it was simply labelled
‘lesion’. Despite the 2008 Australian/NZ Melanoma Guidelines, punch
biopsy was used in 40% of lesions where a melanoma was being considered
clinically. Punch biopsy was used for 32.5% of lesions identified as pigmented
and in a third of suspect non-melanoma skin cancer.
DiscussionDermatosurgery is increasingly being performed by general
practitioners. Whilst many GPs have up-skilled themselves technically by
attending surgical skills workshops, little attention seems to have been devoted
to the communication between doctor and pathologist.
Communication between the medical disciplines is an
essential component of quality medical care. Few of us would regard an
inter-specialist referral with no clinical information as being either
appropriate or adequate. Despite this, practicing clinicians tend not to regard
referral to specialist diagnostic services in the same light. This is
particularly unfortunate as our colleagues in specialist diagnostic services
often have no direct contact with the patient, and are therefore unable to
obtain any clinical information independently.
This study has shown that, in a third of cases, the
histopathologist is not provided with any clinical information to help in the
diagnostic process. There may be a number of reasons for this including both
cognitive and procedural. The referring practitioner may be so confident of
their clinical diagnosis they do not feel it is necessary to share their
opinion. Alternatively they may not know what the lesion is and are embarrassed
to show this. The request form may be completed by a surgical assistant,
ignorant of the potential diagnoses. It may be pressure of time; most request
forms were generated electronically and it requires an extra few minutes to fill
the diagnostic/clinical sections. Most likely however, is a simple lack of
appreciation of the value the pathologist places on good clinical information.
Skin lesions are removed/biopsied for a variety of concerns
including that they are of health, cosmetic, or diagnostic concern (both current
or potential), or because they are a nuisance to the patient. The biopsy
technique used generally reflects the technical ability of the doctor, but it
may also reflect the patient/doctor’s degree of concern about the skin
lesion. Unfortunately, in this study, a significant number of lesions were not
sampled/removed in the most appropriate manner.
Punch biopsy is generally used for diagnostic purposes. It
is simple and heals well, often without sutures. However, it only provides the
pathologist with small, 2 to 5 mm tissue samples to work with and therefore,
clinical information is essential.7-8 Of the 82
punch and incisional biopsies taken, there were unfortunately no clinical
details in 23%, and a further 22% were simply labelled
‘lesion’.
In addition, punch/shave biopsies may not be appropriate in
certain circumstances.8 In a study of 2470
patients with melanoma, punch and shave biopsy significantly increased the odds
of misdiagnosis by 16.6- and 2.6-fold respectively, compared to excisional
biopsy. Moreover, punch biopsy increased the risk of a misdiagnosis with adverse
outcome by 20-fold (p < 0.001). The 2008 Australian/New Zealand guidelines
recommend complete excision of suspect pigmented lesions with a 2 mm
margin.6 This audit showed that 40% of lesions
where a melanoma was considered, and 32.5% of lesions identified as pigmented
lesions, and therefore potentially a melanoma, were punch biopsied. Some of this
may reflect the regional public plastic surgery service’s request for
histological confirmation of non-melanoma skin cancer, prior to allocating
priority for first specialist assessment.
As surgical techniques go, the shave biopsy appears very
simple, although it actually requires a certain degree of understanding of
cutaneous pathology to perform correctly. Whilst it may be appropriate for the
removal of benign lesions such as papillomatous melanocytic naevi, skin tags and
seborrhoeic keratoses, it is not the most appropriate technique for pigmented
lesions where there is diagnostic concern. This study shows that 16% of shave
specimens were inadequate to make a histopathological diagnosis compared to only
1.7% of lesions that had been sampled by excision.
ConclusionThis audit shows that in over a third of histology requests,
diagnostic clinical information was absent. Sixty percent of histologically
confirmed malignant lesions had not been identified on the request form as being
malignant, including 87% of melanomas, 55% of BCCs and 43% of SCCs. The specimen
was inadequate to make a histopathological diagnosis in 6.7% of cases. Finally,
40% of lesions suspected of being a melanoma were sampled by punch biopsy.
Clearly there is room for improvement.
Quality medicine requires good communication. Pathologists
need good clinical information to interpret subtle histological features. Whilst
the size of the tissue sample may never satisfy the pathologist, small
incisional punch biopsies of pigmented lesions, particularly if melanoma is
being considered, may not be appropriate. Shave excisions, whilst simple, are
often suboptimal.
Competing interests: None.
Author information: Marius Rademaker, Hon
Associate Professor, Department of Dermatology, Waikato Hospital, Hamilton;
Murray Thorburn, Specialist Histopathologist, PathLab, Hamilton
Correspondence: Associate Professor Marius
Rademaker, Dermatology Department, Waikato Hospital, Private Bag 3200, Hamilton,
New Zealand. Email: Marius.Rademaker@waikatodhb.health.nz
References:
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