Sub-Saharan African Journal of Medicine

: 2018  |  Volume : 5  |  Issue : 3  |  Page : 99--103

Patterns of significant and unexpected, and critical findings in surgical pathology practice in a university hospital in Nigeria: a 5-year retrospective survey

Almustapha A Liman, Balarabe Kabir, Murtala Abubakar, Shehu Abdullahi, Sani M Shehu 
 Department of Pathology, Ahmadu Bello University Teaching Hospital, Zaria, Nigeria

Correspondence Address:
Almustapha A Liman
Department of Pathology, Ahmadu Bello University Teaching Hospital, Zaria


Critical values or significant and unexpected findings were introduced in anatomic pathology only recently; after showing immense success in clinical pathology practice; and it still is a subject of variation according to the differences in geographical or work setting and among pathologists and clinical specialists. It has been demonstrated that customizing the list at a given institution to address all potential diagnoses and results necessary and when framed into a policy can serve as important measures for optimizing patients’ safety. This study was conducted to demonstrate the prevalence and distribution patterns of these findings and to raise the awareness of the local pathologists and other clinicians to the evolving concept and practice of significant and unexpected values in surgical pathology. We studied the prevalence of significant and unexpected findings in surgical pathology through a retrospective review of 14,696 surgical pathology reports seen in a large tertiary hospital over a five-year period. Based on literature and our experience, we selected 10 categories of possible surgical pathology results that can justify an urgent communication with the clinician for immediate action and extracted them from the pool; they were analyzed and presented in descriptive tabular format. The study established a prevalence of 3.15% and outlined the distribution and frequency ratios of the 10 specific categories of results. The prevalence as established here was comparatively high, hence, the need for institutionalizing critical diagnoses guidelines in our surgical pathology practice as a patient safety initiative.

How to cite this article:
Liman AA, Kabir B, Abubakar M, Abdullahi S, Shehu SM. Patterns of significant and unexpected, and critical findings in surgical pathology practice in a university hospital in Nigeria: a 5-year retrospective survey.Sub-Saharan Afr J Med 2018;5:99-103

How to cite this URL:
Liman AA, Kabir B, Abubakar M, Abdullahi S, Shehu SM. Patterns of significant and unexpected, and critical findings in surgical pathology practice in a university hospital in Nigeria: a 5-year retrospective survey. Sub-Saharan Afr J Med [serial online] 2018 [cited 2019 Dec 8 ];5:99-103
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The idea of critical values (critical results/diagnoses) in laboratory medicine was introduced by George D. Lundberg of the Los Angeles County-USC Medical Center in 1972.[1] Critical values or findings are result(s) of laboratory values representing a significant pathophysiological state of the patient associated with a life-threatening condition that would require immediate attention.[1],[2],[3] Timely communication of critical laboratory values has been recognized as essential in good clinical care. This idea has been highly successful in clinical laboratory practice.

The recent extension of this concept into anatomic/surgical pathology practice and its significance in terms of policy, documentation, and timely communication as a quality tool for improving patient safety and patient management outcome is gaining ground. This has been reinforced by its endorsement by the Association of Directors of Surgical and Anatomic Pathology (ADASP) and the College of American Pathologists (CAP) and the Clinical Laboratory Improvement Amendments of 1988, section 493.1109, and its institutionalization into their accreditation requirements.[4],[5],[6],[7] This practice is, however, still not universal in anatomic pathology practice.[8]

Results in surgical pathology, unlike in clinical laboratory, are peculiar by the fact of being qualitative in character rather than quantitative or numerical and are not subject to “cut-offs.”[9] Several anatomic pathologists consider the result of surgical pathology as vital and just as important as the critical values in other laboratories, but one for which the timing is not as crucial, hence, the postulating of terms like urgent diagnoses − defined by the CAP and ADASP as medical conditions that, in most cases, should be addressed as soon as possible; “vital values,” “significant and unexpected values,” in anatomic pathology is being considered by some as more appropriate in surgical pathology practice.[9],[10],[11],[12]

Several surveys on the subject have also revealed a wide range of opinions among pathologists and between pathologists and clinicians on categories that should qualify as critical findings, the need for clinician’s notification, the degree of urgency, and the method of communication to be used.[10] Methods are currently being explored to increase the ability of the pathologists and cytopathologists to identify these diagnoses, including optimization of their workstations for better access to the electronic medical records.[12] What is generally agreed upon, although, is that the issue deserves attention and the necessity of the need for laboratories to define their vital values and the customization of the critical diagnoses list at any given institution.[3],[4],[6],[10],[13]


This article is a descriptive and prescriptive study to demonstrate the rate of occurrence and distribution patterns of significant and unexpected diagnoses in surgical pathology practice in Ahmadu Bello University Teaching Hospital (ABUTH) and possibly raise awareness and make case for a new policy in our surgical pathology practice.


All the surgical pathology cases seen at ABUTH over a 5-year period (January 2013 to December 2017) were reviewed, and cases that met up the criteria as significant and unexpected diagnoses in surgical pathology, as adopted from CAP Laboratory Program Laboratory Accreditation checklist and the ADASP template, and as modified with respect to our experience of the local surgical pathology practice (10 categories outlined) [[Table 1]] were extracted.[2],[3],[4] The data was analyzed and displayed in descriptive statistical format as tables [[Table 2],[Table 3],[Table 4],[Table 5],[Table 6]].{Table 1}{Table 2}{Table 3}{Table 4}{Table 5}{Table 6}


The study found that 3.15% of the 14,696 cases reviewed fell in the categories outlined, and of these, in declining order, insufficient/absent biopsy material (43.63%), uterine contents − in pregnancy setting − without villi or trophoblasts (16.20%), and unexpected malignancies (14.04%) had the highest frequency ratios with the lowest ratio belonging to the category of leukocytoclastic vasculitis (0.22%) [[Table 2]].

Sixty-five cases of unexpected malignancies, of which 46 (70.77%) were primary tumors and 19 (29.23%) were secondaries, were observed [[Table 2]]. A majority of them were carcinomas, followed in decreasing frequency by sarcomas (13) and hematolymphoid malignancies (4), with one melanoma and a single mixed tumor. All the 19 metastatic lesions were carcinomas.

[Table 4] shows frequency ratios of margin involvement by anatomic site that constituted the fourth highest finding in the study (12.96%). Tumors of soft tissue and bone exhibited the highest rate of margin involvement (23.33%) followed by skin cancers (20%), breast malignancies (18.33%), head and neck neoplasms (15%), and orbito-ocular tumors (10%). The kidney had the least frequency with 1%.

In 15 cases (3.24%), there was significant disagreement between fine needle aspiration (FNA)/cytologic diagnoses and the final tissue diagnoses [[Table 5]]. In the event, eight cases that were released as benign were found to be malignant diseases, with two cases in which negative Pap smears turned out to be squamous carcinoma and cervical intraepithelial neoplasia (CIN) III, respectively, upon surgical biopsy, whereas two diagnosed cases of high-grade intraepithelial neoplasia were found to be mere inflammatory lesions. On the contrary, two malignant cases were later recorded as benign. A lymph node aspirate that was diagnosed as reactive was also reviewed to be tuberculous adenitis.

Significant disagreement between the immediate incision biopsy diagnoses and the final diagnoses after surgical excision constituted 4.54% (21 out of the 463 cases). Of these categories, nine cases involved the head and neck region with three cases each recorded from the gastrointestinal tract, the female genital tract, the limbs, and the trunk; the remainder spread out between the breast, the urinary bladder, and the paravertebral region. Most of the discrepancy (17 cases in all) involved the crossing of the benign–malignant category barrier.

Other findings are [[Table 2]] 10 cases of neoplasms causing paralysis, making up 2.16% of all the cases, and three cases of microbial organisms in known immunocompromised patients representing only 0.65% of the total.


Although the idea of critical results or diagnosis has been extended to anatomic pathology in general, some have maintained the case that the term “critical result” has limited application to anatomic pathology because even a report like malignancy rarely represent a condition that is imminently life-threatening requiring immediate attention. In a survey of 1130 laboratories by CAP it was obvious most pathologists would rather the determination of “critical” be left up to their judgment as physicians.[3] In the United States, at least, reporting of laboratory critical values in anatomic pathology has become an issue of national attention as illustrated by policy statements by CAP, ADASP, and the National Patient Safety Goals of the Joint Commission of Healthcare Organizations.[4],[5],[6] Many laboratories there now have a written policy that addresses the communication and documentation of these findings in surgical pathology, specifically, and anatomic pathology, in general.[3],[14],[16] In most of these laboratories and also in hospitals, the guidelines contain five or more conditions in a strict list of must-call diagnoses.[3]

In the absence of established guidelines, common sense and the personal experience of the pathologist typically determines if and when immediate contact with the physician is needed. On the whole, there is scarcity of literature specifically addressing critical values or significant and unexpected findings in surgical pathology and we have not come across articles describing the patterns in these findings.

The discussion on significant and unexpected and critical findings in surgical pathology is not really settled, with differing usage of terminology for cases that require prompt clinicians’ notification ranging from “critical values,” “significant and unexpected findings,” “urgent results,” and “life-threatening results,” but most have considered that using the term “significant and unexpected finding” is quite reasonable.[6],[14],[15],[16] While some workers have emphasized that only treatable immediately life-threatening diagnoses be selected and flagged, others have also recommended that the results should be only those that are actionable.[17],[18]

The very high prevalence rate − 3.15% − of findings in this survey are strikingly upset by the duo of insufficient or absent biopsy material and uterine contents − in background of pregnancy − without villi or trophoblasts, together accounting for almost 60% of all, which in themselves are not specific disease conditions or pathologic events, rather attributable to underprovided surgical/radiological techniques. Pereira et al.[14] notably recorded 0.49% in a widely acknowledged review of 2659 surgical pathology reports. In a recent 3-year study of two hospital laboratories in Florida, USA, Renshaw and Gould[17] similarly reported a 0.5% rate.

Thus, our most substantial results, in practical fact, would be in the categories made up of unexpected malignancies, positive margins, and the respective diagnostic disagreements between immediate incision biopsy and final excision biopsy, between FNA and histology, as well as between primary and outside pathologists. Additional noteworthy results were paralysis-causing neoplasms and the presence of microbial agents in a background of immunosuppression. Only one case of leukocytoclastic vasculitis, an idiopathic histologic reaction, was seen in a variety of disease entities, forming the lowest rate of all the categories.


The prevalence, in terms of frequency ratio of occurrence, of significant and unexpected diagnoses in surgical pathology practice as established here, was comparatively high, hence, the need for institutionalizing critical diagnoses guidelines in our surgical pathology practice as a patient safety initiative.

Presentation at a meeting

An abstract from this work was presented at the 2018 Nigerian Surgical Society Conference that held in ABUTH, Zaria, on December 7, 2018.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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