|Year : 2020 | Volume
| Issue : 6 | Page : 648-652
Clinicopathological correlation in the diagnosis of skin diseases: A retrospective study
Ruby Venugopal1, Prerna Shankar2, Vikas Pathania1
1 Department of Dermatology, Command Hospital, Pune, Maharashtra, India
2 Department of Community Medicine, AFMC, Station Health Organization, Pune, Maharashtra, India
|Date of Submission||05-Jan-2020|
|Date of Decision||17-Feb-2020|
|Date of Acceptance||25-Jun-2020|
|Date of Web Publication||6-Nov-2020|
Station Health Organization, Pune - 411 040, Maharashtra
Source of Support: None, Conflict of Interest: None
Introduction: Skin biopsy is an indispensable tool in dermatological diagnosis.Various factors that influence the outcome of a biopsy include information recorded on the histopathology request form by the treating dermatologist to the reporting pathologist. Conversely, a good biopsy report is vital for the clinician to arrive at a diagnosis. Materials And Methods: The present study was conducted at a tertiary care hospital in the form of a retrospective investigation of histopathology requisition forms and reports of skin and mucosal biopsies done over a period of one year.If the pathological diagnosis was definite and matched one of the clinical diagnoses, it was grouped under the category definite and consistent. If the pathologist gave a descriptive diagnosis that matched one of the clinical diagnoses, it was grouped under the category descriptive and consistent. If the pathologist gave a definite diagnosis that did not match any of the clinical diagnoses, it was grouped under definite and inconsistent and if the pathological diagnosis was descriptive and did not match any clinical diagnoses, it was grouped under descriptive and inconsistent. Data analysis was done using R Statistical Software v3.6.0 (R Statistical Corp, Vienna, Austria). Level of significance was set at p<0.05. Results: A total of 403 skin biopsy requisition forms and their reports were analysed. 46.5% were given a definite pathological diagnosis consistent with the clinical diagnosis, 21% were given a descriptive pathological diagnosis consistent with the clinical diagnosis, 6% had a definite pathological diagnosis inconsistent with clinical diagnosis and 26.5% had a descriptive pathological diagnosis inconsistent with the clinical diagnosis. Conclusion: The present study has shown that clinicopathological consistency in diagnosing skin diseases is 67.5%. Providing comprehensive clinical description and repeat biopsy increases the diagnostic accuracy rate.
Keywords: Clinicopathological correlation, histopathology, skin biopsy
|How to cite this article:|
Venugopal R, Shankar P, Pathania V. Clinicopathological correlation in the diagnosis of skin diseases: A retrospective study. Med J DY Patil Vidyapeeth 2020;13:648-52
|How to cite this URL:|
Venugopal R, Shankar P, Pathania V. Clinicopathological correlation in the diagnosis of skin diseases: A retrospective study. Med J DY Patil Vidyapeeth [serial online] 2020 [cited 2020 Dec 3];13:648-52. Available from: https://www.mjdrdypv.org/text.asp?2020/13/6/648/300149
| Introduction|| |
Skin biopsy is one of the most important diagnostic procedures performed in dermatology practice. There are various factors that can influence the outcome of a biopsy. The information recorded on the histopathology request form is a crucial data set provided by the treating dermatologist to the reporting pathologist. Pathologists rely upon clinical information provided to interpret the histopathology findings. Similarly, a good biopsy report is vital for the clinician to arrive at a diagnosis. Many previous studies on clinicopathological consistency have observed that dermatologists have a significantly higher rate of clinical diagnostic accuracy compared to other specialties.,, The aim of our study was to investigate the consistency of clinical diagnoses with subsequent pathological diagnoses in various categories of skin diseases and to determine the factors that affected consistency.
| Materials and Methods|| |
Our study was conducted at the department of dermatology of a tertiary care hospital. A retrospective investigation of histopathology requisition forms and their reports of skin and mucosal biopsies done over a period of 1 year was analyzed. Prior approval by the institutional ethics committee was obtained. Clinical parameters recorded in the requisition forms and pathological information provided in the biopsy reports were recorded, and unavailable data were recorded as missing.
Age and gender of every patient were recorded. The type of biopsy was classified as incisional, excisional, punch, and shave. The site of biopsy was classified into seven categories as head/neck, hair/scalp, oral mucosa, trunk, upper extremity, lower extremity, and genital region. The disease duration was recorded in days. The location of skin disease was recorded as mentioned or not mentioned. The clinical description provided by the dermatologist was categorized as sufficient, insufficient, or absent based on the clinical information and differential diagnoses provided. The number of clinical differential diagnoses provided was also recorded. Based on the clinical diagnoses, each biopsy was categorized into broad clinical groups.
The pathological diagnosis provided was classified as a definite report or descriptive report. Any additional tests performed on the biopsies were noted and classified as histochemical tests, immunohistochemical tests, and immunofluorescence. The time taken for reporting was also noted. We recorded the cases where a repeat biopsy was taken due to clinical or pathological indications.
The biopsies that were investigated were grouped into four categories based on the clinicopathological correlation. If the pathological diagnosis was definite and matched one of the clinical diagnoses, it was grouped under the category definite and consistent. If the pathologist gave a descriptive diagnosis that matched one of the clinical diagnoses, it was grouped under the category descriptive and consistent. If the pathologist gave a definite diagnosis that did not match any of the clinical diagnoses, it was grouped under definite and inconsistent, and if the pathological diagnosis was descriptive and did not match any clinical diagnoses, it was grouped under descriptive and inconsistent. Categories one and two were considered as clinicopathological consistency, and categories three and four were considered as clinicopathological inconsistency. The clinicopathological consistency was evaluated separately for each broad clinical group. We also analyzed various factors that may affect the clinicopathological consistency, including the type of biopsy, disease duration, location of disease, clinical description, time taken to report, and the use of additional evaluations.
Data analysis was done using R-Statistical software v3.6.0 (R Statistical Corp., Vienna, Austria). Descriptive statistics were elaborated in the form of measures of central tendency (means/medians) and measures of dispersion (standard deviations/interquartile ranges) for continuously distributed data and frequencies and percentages for categorical data. Group comparisons were made using t-test/Wilcoxon test for continuously distributed data and Chi-squared test/Fisher's exact test for categorical data. The level of statistical significance was set at P < 0.05. Ethical approval for the study was obtained from the Institutional Review Board (letter no. IEC S. no. IEC/2018/115 dated August 7, 2018).
| Results|| |
A total of 403 skin biopsy requisition forms and their reports were analyzed. Out of the 403, 250 (62%) were male patients and 153 (38%) were female patients. The age of the patients was found recorded in 400 forms. Patients' age ranged from 5 to 87 years with a mean age of 44 ± 19 years. The type of biopsy performed was mentioned in all forms and was categorized as follows: 73% incisional, 7.7% excisional, 19.4% punch, and 0% shave. Out of the 384 (95.28%) biopsies in which the site of the biopsy was indicated, the most frequent region was lower extremity (31%), followed by trunk (20.8%), upper extremity (19.1%), head/neck (17.9%), hair/scalp (3.2%), genital region (2.7%), and oral mucosa/lip (0.5%). The disease duration was mentioned in 396 (98.3%) biopsy forms. The disease duration ranged from 1 to 14,600 days, and the average duration was 563 ± 1532 days.
Clinical description was found entered in all 403 reports, out of which 376 (93.3%) had sufficient description and 27 (6.7%) had insufficient description. The location of skin disease was recorded in 399 (99%) of reports. The number of clinical diagnoses ranged from 0 to 6 (mean 2.12 ± 1.08). The time taken for pathological reporting ranged from 2 to 15 days (mean 6.86 ± 1.95).
Additional tests were performed in 173 (42.92%) biopsies. The additional tests performed included histochemical tests in 94 (23.3%) cases, immunofluorescence tests in 50 (12.4%) cases, immunohistochemical tests in 24 (6%) cases, histochemical and immunohistochemical tests in 3 (0.7%) cases, and immunofluorescence and immunohistochemical tests in 1 (0.2%) case. Pathological report recorded a definite diagnosis in 211 cases (52.4%) and a descriptive diagnosis in 192 cases (47.6%). Repeat skin biopsy was done in 21 (5.2%) cases.
Out of the 403 cases examined, 46.5% were given a definite pathological diagnosis consistent with the clinical diagnosis, 21% were given a descriptive pathological diagnosis consistent with the clinical diagnosis, 6% had a definite pathological diagnosis inconsistent with clinical diagnosis, and 26.5% had a descriptive pathological diagnosis inconsistent with the clinical diagnosis. Based on these findings, it was determined that 67.5% of the cases were clinicopathologically consistent and 32.5% of the cases were clinicopathologically inconsistent [Table 1].
The cases were grouped as per the clinical diagnosis and were further ranked as per clinicopathological consistency or inconsistency. In the group which had clinicopathological consistency, 33.3% were given a diagnosis of inflammatory dermatoses, 23% of infectious diseases, 7% of bullous diseases, and 7% of benign diseases.
Among the reports with clinicopathological consistency, it was found that in 71% of the cases, the pathological diagnosis was consistent with the first clinical diagnosis; in 20.8% of the cases, it was consistent with the second clinical diagnosis; in 5.5% of the cases, it was consistent with the third clinical diagnosis; in 1.1% of the cases, it was consistent with the fourth clinical diagnosis; and in 1.4% of the cases, it was consistent with the fifth clinical diagnosis.
When we analyzed the relationship between the disease groups and clinicopathological consistency, we found that there was a high level of clinicopathological consistency in the genetic diseases (100%), followed by bullous diseases (79.1%), environmental diseases (73.3%), and inflammatory dermatoses (72%). Clinicopathological consistency was low for malignant tumors, metabolic diseases, diseases of adnexal structures, regional and special dermatoses, and pigmentary disorders [Table 2].
There were a total of 125 reports classified as inflammatory dermatoses. Out of these 125, 66 (52.8%) were given a definite pathological diagnosis that was consistent with the clinical diagnosis, 24 (19.2%) were given a descriptive pathological diagnosis that was consistent with the clinical diagnosis, 7 (5.6%) were given a definite pathological diagnosis that was inconsistent with the clinical diagnosis, and 28 (22.4%) were given a descriptive pathological diagnosis that was inconsistent with the clinical diagnosis. Therefore, in the inflammatory dermatoses group, the clinicopathological consistency was 72%.
Clinicopathological consistency was found to be higher in those patients in whom sufficient clinical description was provided and also in the group where additional tests were performed on the biopsy specimen. No correlation was observed between clinicopathological consistency and type of biopsy. Specifying the site of biopsy or location of skin disease had no effect on clinicopathological consistency [Table 3].
|Table 3 : Distribution of factors influencing clinicopathological consistency and their association with|
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| Discussion|| |
The outcome of a skin biopsy is influenced by various factors such as quality of clinical data provided in the histopathological requisition forms, type of biopsy, selection of lesion biopsied, processing of tissue, and use of additional tests such as special stains, immunohistochemistry, or direct immunofluorescence wherever indicated. Our study has shown that clinicopathological consistency in diagnosing skin diseases is 67.5%. In a retrospective study of clinicopathological consistency in 3949 skin biopsy reports, the diagnostic accuracy rate was 76.8%. A similar retrospective audit of skin biopsies investigating all types of skin diseases arrived at a clinicopathological concordance of 59.8%. Prior studies performed mainly in isolated groups of skin disorders such as benign and malignant skin tumors arrived at a concordance rate ranging from 44% to 96.5%.,,,,,,,
Many of the previous research on clinicopathological consistency have supported the importance of providing adequate clinical information to the pathologist. Aslan et al. observed a significant decrease in clinicopathological concordance rate when biopsy specimens were re-examined without clinical diagnosis. Rajaratnam et al. observed that pathologists when blind-folded about clinical details of patients made an accurate diagnosis in 55% of cases which increased to 78% when they were provided with the requisite clinical information. Rademaker and Thornburg assessed the quality of clinical information provided in the biopsy requisition forms and observed that in over a third of them, sufficient clinical information was absent. A study on influence of evaluation of clinical pictures on the histopathologic diagnosis of inflammatory skin disorders observed that evaluation of clinical images by pathologists increased the diagnostic accuracy by 16.6%. In our study, 93.3% of biopsy requisition forms had sufficient clinical description. Our study also observed a significant association between adequacy of clinical data provided and clinicopathological correlation. In contrast, Balasubramanian et al. observed no significant association between diagnostic outcome and adequacy of clinical details provided.
We observed that clinicopathological consistencies varied in different disease groups. The highest concordance was observed in genetic diseases (100%), followed by bullous diseases (79.1%), environmental diseases (73.3%), and inflammatory dermatoses (72%). Aslan et al. observed the highest concordance in connective tissue diseases (96.8%), followed by metabolic diseases (95.1%), bullous diseases (94.6%), inflammatory dermatoses (93.9%), and hereditary diseases (92.5%). In contrast, our study showed a much lower degree of correlation in connective tissue diseases (68.4%) and metabolic diseases (50.0%).
The lower concordance rates that we observed could be attributed to inadequate or inappropriate (wrong biopsy site selection) specimen. The variation in concordance rates could also be due to the variations in referral of cases for skin biopsy as clinically evident cases were mostly not biopsied in our study.
Cutaneous malignancies had a clinicopathological consistency of 46.4% in our study. A study conducted in the Indian population had a similar lower concordance rate (55% in Balasubramanian et al.) for cutaneous malignancies in contrast to much higher concordance rate (89%) in Aslan et al. The lower incidence of cutaneous malignancies in the Indian skin type may account for the low diagnostic accuracy in this category.
In our study, the pathological diagnosis was consistent with the first clinical diagnosis in the majority (47.4%) of cases. The pathological diagnosis was consistent with the second and third clinical diagnoses in 13.9% and 3.7% of the cases, respectively. Aslan et al. observed a similar finding in their study. These results indicate that the clinical differential diagnoses listed in the requisition forms are in the correct order of relevance. About 5.2% of the cases underwent repeat biopsies in our study. Out of them, 92% were provided a similar list of clinical diagnoses in the first and subsequent biopsies, and there were 100% clinicopathological consistencies in the repeat biopsies. The diagnostic accuracy rate becoming higher may be due to various factors such as disease becoming more evolved with time, more appropriate, and adequate specimen being submitted in secondary biopsy or due to better involvement of clinician (better clinical communication) and pathologist (careful examination of repeat biopsies) in cases posing diagnostic dilemma.
Our study demonstrates that providing adequate clinical information and performing additional tests influenced clinicopathological consistency. Disease duration, type of biopsy or specifying the site of biopsy, or location of skin disease had no significant effect on clinicopathological consistency. Except for diseases involving the subcutaneous tissue where punch biopsy has been found to be better, there is no relevance of the type of biopsy with respect to diagnostic accuracy. These findings highlight the role of adequate clinical information in clinicopathological consistency.
| Conclusion|| |
Dermatologists often exceedingly rely on histopathological examination of the skin for diagnostic purposes. Our study has shown that clinicopathological consistency in diagnosing skin diseases is 67.5%. As discussed in our study, providing a comprehensive clinical description increases the diagnostic accuracy rate. Repeat biopsy may be useful in certain cases to arrive at an accurate and definite diagnosis.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]