Medico-Legal Considerations on the Clinico-Instrumental Correlation and the Role of Expertise in the Dermatological Diagnostic Pathway

Abstract

Italian Court of Cassation Ruling Decree 30032 of 30 October 2023 discusses a medical malpractice case concerning the diagnosis of dermatofibrosarcoma protuberans and the alleged diagnostic and therapeutic delay. By examining how the ruling frames the role of histopathology in proving pathology benignity, authors prompt to reflect on diagnostic path, the allocation of the burden of proof, and the role of dermatologist’s expertise in professional liability issues. Over a four-year period, five health professionals were involved in a claim concerning an initial diagnosis of an epidermoid cyst and a subsequent diagnosis of dermatofibrosarcoma protuberans. The plaintiff questioned the delay in diagnosis, and the Court of Cassation found two physicians liable because they could not prove that the treated pathology was initially benign. We argue that equating diagnostic correctness exclusively with histological confirmation is unnecessary, both clinically and legally, in typical cases, if the reasoning and findings are adequately documented. Additionally, we examine the value of dermatologists’ experience and the scope of professional competence as measures of liability. Finally, we outline the minimum standards of clinical documentation necessary to make the diagnostic pathway traceable and verifiable. The diagnostic process is a discretionary effort that integrates multiple sources of information, both instrumental and experiential, to reach the most reasonable hypothesis. While histopathology is a crucial tool, it is not the sole gateway to a correct diagnosis of every cutaneous alteration. Adequate disclosure and structured documentation of the diagnostic reasoning are fundamental to the care process and fair assessment of professional responsibility.

1. Introduction

The case discussed by the Italian Court of Cassation, III Civil section, in the ruling decree of 30 October 2023 n. 30032, invites reflection on appropriate diagnostic pathways, dermatological competencies, and standards of proof in the context of healthcare liability assessment [1]. The case concerns a patient who received an initial clinical diagnosis of epidermoid cyst and, four years later, a new diagnosis of dermatofibrosarcoma protuberans (DFSP).

Authors take the ruling as a starting point to examine the meaning and multimodality of diagnostic reasoning and confirmation, and the overall impact these elements have on the burden of proof in dermatology and dermato-oncology. The authors, while acknowledging the limitations of a single ruling analysis, frame the discussion around broader principles, relevant to clinical practice and medico-legal evaluation both in the Italian and international context. In fact, in discussing the dermatologists’ expertise in the diagnostic process, the authors clarify the role and value of instrumental assessments alongside clinical experience, the relative significance of the indication for histopathological examination, the integration of diagnostic sources in both diagnostic and therapeutic reasoning, also including their relevance as sources of evidence in trial, the meaning of concordance among clinical findings in distinguishing between benign and malignant conditions, the communication of diagnostic uncertainty, and the informational involvement of the patient. They also consider how diagnostic appropriateness relates to the organization of healthcare services, in contrast with defensive medicine behaviors. In fact, the balance between clinical needs, medical diagnostic assurance, quality assurance, evidentiary requirements, and the daily organization and management of patients with dermatological disorders in hospital and outpatient settings must be considered.

The issue of diagnosis in dermatology is in fact extremely abundant in the consistent malpractice literature [2]. The malpractice literature frequently reports delayed or missed diagnoses leading to treatment delays, in the most part of litigations regarding melanoma and non-melanoma skin cancer [3,4,5,6]. Incorrect surgical and biopsy procedures within the diagnostic path have also been reported [7].

Then, this opinion paper aims to articulate a clear framework linking clinical decision-making within diagnostic path and standard operating procedures, diagnostic insight and instrumental support, documentation, and medicolegal standards in dermatology that could impact everyday practice.

2. Case Law Reconstruction

The case law stems from a claim of injury resulting from the treatment of a dermatological condition. According to the plaintiff, the problem began after undergoing outpatient surgery to remove an epidermoid cyst from the scalp in 1999. At the time of the surgery, the dermatologist neither mentioned nor recommended a histological examination to support the diagnosis of an epidermoid cyst. Several months later, in November 1999, the lesion recurred, and a second physician, not a specialized dermatologist, performed a similar excision without recommending or performing histology. In 2002, new lesions appeared in the same area, prompting the plaintiff to seek medical attention elsewhere. The patient was ultimately diagnosed with DFSP at a specialized cancer center. As a result, the patient underwent extensive treatment, including the removal and reconstruction of a large portion of the scalp. The plaintiff then sought reparation from the first two doctors, arguing that their failure to perform histological examination of the excised tissue resulted in a significant diagnostic delay.

After hearing from court-appointed experts, the first instance judge upheld the claim against the doctors. Although the expert report acknowledged the lack of sufficient information to definitively determine the clinical scenario the first doctor faced, it cited the close chronological connection and subsequent disease progression to conclude that DFSP was present at the time of the first surgery. Thus, the first doctor was held liable. Regarding the second doctor, the judge reaffirmed liability due to the combination of “lesion recurrence and reported intraoperative bleeding, which should have raised diagnostic doubts and led to a histological examination” [1]. The experts concluded that an earlier diagnosis would have likely avoided more invasive and damaging surgery, resulting in a smaller scar.

This decision was challenged, and the Court of Appeals only upheld the plaintiff’s claim for lack of informed consent. The Court of Appeal judges reviewed the initial expert report and disagreed with the initial decision, asserting that an epidermoid cyst is “significantly different” from a DFSP. It was considered unlikely that two physicians, including a dermatologist, would miss such a significant difference. Therefore, it was likely that the first physician did not consider it necessary to perform a histologic examination upon diagnosing an epidermoid cyst, even though this was not documented in writing. In short, the Court of Appeals found insufficient evidence that DFSP was already present at the time of the first excision and considered a subsequent development more plausible. Then, the plaintiff appellate decision was challenged before the Court of Cassation.

Ultimately, the Court of Cassation partly overturned the lower courts’ conclusions on liability, stating that the first two physicians failed to recommend a histologic examination after removing what was initially diagnosed as an epidermoid cyst on two separate occasions. The Court further held that, in response to the plaintiff’s allegations, the burden of proof lay with the physicians to demonstrate both the benignity of the lesions and the appropriateness of not requesting histopathology. In other words, since negligence was alleged by the plaintiff, it was incumbent upon the healthcare professionals to provide evidence demonstrating that they had acted appropriately, according to best evidence. Additionally, the Court of Cassation made several observations on the lack of informed consent.

3. Discussion

3.1. Dermatological Characteristics

Epidermoid cysts, also known as epidermal cysts, are the most common type of cutaneous cyst. They are sometimes erroneously called sebaceous cysts. They present as well-circumscribed, skin-colored, yellowish, painless nodules that are mobile in the deeper layers of the skin. Often, they have a clinically visible central punctum that represents the occluded orifice of the pilosebaceous follicle. Sizes vary from a few millimeters to several centimeters, and an epidermoid cyst is usually diagnosed clinically and rarely requires additional instrumental examination [8,9].

By contrast, dermatofibrosarcoma protuberans (DFSP) is a rare and locally aggressive soft tissue sarcoma of the skin, with an estimated incidence of between 0.8 and 4.5 cases per million people per year [10,11,12]. The neoplasm most commonly occurs in adults but has been observed in all age groups, including children and the elderly [10,13]. Early DFSP typically presents as a slowly enlarging, asymptomatic plaque with pink to brownish-red hues and nonspecific features that may delay recognition. As it grows, firm nodules develop and adherence to the subcutis becomes evident. Ulceration or bleeding may also occur, prompting medical attention [14].

The differential diagnosis for DFSP is extensive and may include conditions such as keloids, epidermoid cysts, dermatofibromas, leiomyomas, desmoplastic melanoma, morphea, and other cutaneous neoplasms [15]. Some entities within this spectrum generally require histopathologic confirmation to establish the diagnosis, while others are diagnosed clinically without ancillary tests in their classic presentation.

Accordingly, the differential is not symmetrical. A lesion suspected to be DFSP typically requires histopathologic examination. However, a classic scar, keloid, dermatofibroma, or epidermoid cyst has distinct clinical features, does not mimic DFSP, and does not, in usual presentations, require histology. Deviation from the typical presentation, rapid evolution, or persistence despite appropriate management warrants further diagnostic investigation.

3.2. Dermatologist, Diagnostic Path and Instrumental Examinations

Dermatology is a highly sensory specialty that relies primarily on visual and tactile assessments. Unlike other medical specialties, dermatology does not routinely use diagnostic instruments that produce documentary evidence, such as electrocardiograms. Although photographs and video-dermoscopic images are sometimes taken, they are generally intended for monitoring rather than diagnosis. Moreover, these images are not universally used due to practical difficulties and regulatory complexities [16]. The absence of a routine instrumental trace does not mean an absence of evidence. In typical cases, the evidence is clinical (and dermoscopic when appropriate) and stays in the recorded description of morphologies, contexts, and reasoning [17].

Dermatologists in Italy are qualified to differentiate between various dermatological conditions after four years of specialized training following their medical degree. Dermatologists may reasonably conclude benignity based on explicit diagnostic reasoning when clinical findings are concordant. Further tests should be reserved for atypical, discordant, recurrent, or complicated presentations [18]. Requiring an instrumental assessment and record in every case would conflate appropriate diagnosis with defensive documentation. For instance, while ultrasound can support the diagnosis of an epidermoid cyst, mandating ultrasound for every cyst solely to generate proof for potential litigation would be both clinically unsound and systemically detrimental.

The issue of defensive medicine practices is indeed increasingly relevant, understood as those behaviors for diagnostic confirmation that are useful solely as an additional source of defensive evidence in the case of a claim [19]. These practices should instead be differentiated from appropriate and correct behaviors of diagnostic comparison and assurance, such as a second opinion or, indeed, a histopathological examination, which find their rationale in suspicious lesions, atypical presentations, or unusual evolutions [20]. As with dermatoscopy, every diagnostic tool and activity is part of a broader diagnostic process that engages the specialist in a much wider manner, and in which non single activity or tool is exclusive, mandatory, or determinative [21]. In these terms, the specialist’s diagnosis is robust when actions are reasoned within a process consistent with guidelines, with a thoughtful selection and documentation of the tools and steps leading to the proposed diagnostic hypothesis.

Indeed, while an epidermoid cyst and a dermatofibrosarcoma are quite different, the latter requiring complete excision with clear margins, the judge ruled that those liable of diagnostic failure must prove this “very obvious difference”, while lacking precisely the steps that led to the initial diagnostic hypothesis. Then, the decision highlights the need for the first dermatologist to demonstrate that, with a further diagnosis od dermatofibrosarcoma, the treated lesion was undoubtedly benign. In the specific case, the absence of histology was read as absence of proof of benignity at time T0. However, such a reading must be contextualized, as it lacks precisely the steps that led to the initial hypothesis (such as supporting images, descriptions, or documented actions) and should not be turned into a de facto obligation to perform confirmatory testing, histological or otherwise, unless the clinical reasoning is granted proper probative value [22].

In many cases, the dermatologist’s description is the diagnostic source, and its translation into the medical record is the primary source of evidence. Thus, based on the description and overall data in the outpatient/day surgery report, the healthcare provider can support a correct diagnosis and its benign nature. This demonstrates adequate fulfillment of their duty and the absence of an indication for histologic examination. Otherwise, the fundamental principle of healthcare professions based on discretionary judgment would be undermined. This is particularly critical in areas where diagnoses are primarily based on the integration of medical history and clinical examination [23].

The long-standing medical-legal debate about the need for instrumental ascertainment of minor disabling injuries from traffic accidents appears to be resurfacing here. Article 32 of the Italian Law of 24 March 2012, No. 27, required injuries to be “instrumentally ascertained” thus that limiting diagnosis to instrumental verification. For instance, in cases of cervical whiplash resulting from a motor vehicle accident, injury to the cervical spine must be documented by an instrumental examination, such as a dynamic cervical spine X-ray or spinal CT scan. Without this documentation, the overall medical-legal evaluation could be considered inadequate. The Constitutional Court partially discussed this law in a 2014 ruling and the Court of Cassation, III Civil Section, further clarified it with rulings of 26 May 2020, n. 9865, and 22 December 2022, n. 37477 [24,25]. It is now established that physicians may reach a diagnosis through a comprehensive assessment, including patient interviews, anamnesis, observations, physical examinations, and instrumental tests. The last are not mandatory. By analogy, dermatology should not be forced into “instrumentalization by default”; the correct legal question is whether the contemporaneous clinical reasoning was appropriate and documented, not whether an instrumental test exists for every benign-appearing lesion.

3.3. Informative Path, Clinical Records, and Critical Considerations for Daily Clinical Practice

The decision highlights key issues, such as providing adequate information to patients, obtaining informed consent, and additional burden of proof. In fact, Italian law requires written consent for any health treatment, especially for invasive procedures such as surgery. This plays a decisive role in terms of the patient’s self-determination in healthcare and litigation prevention [26]. Notably, the ruling reports that “neither of the two treating physicians asked the patient for informed consent prior to the surgery. Neither physician warned the patient of the importance of a prior histologic examination of a piece of the neoformation” or explained why histology might not be necessary in a typical presentation.

The issue of informed consent is relevant in this malpractice case and, while commonly cited in additional compensation claims, it underscores the importance of comprehensive documentation of the diagnostic and treatment process, including patient information [5]. Particularly for independent practitioners with direct contractual obligations to their patients and in less structured organized health settings. From this perspective, consent and clinical documentation serve different functions: patient self-determination and traceability of diagnostic reasoning. The decision to manage a lesion directly or refer to the patient is part of the traceable reasoning within the clinical record and must be justified in light of expertise, resources, and clinical presentation [2]. Therefore, while it is reasonable to expect a qualified dermatologist to differentiate between a classic epidermoid cyst and DFSP and inform the patient, a physician without sufficient expertise in dermatology should advise the patient to see a qualified specialist in a qualified center [27]. Most notably, the decision does not address the frequent issue of demonstrating that the physician acted appropriately in cases of alleged delayed diagnosis of a neoplastic lesion. Rather, it specifically addresses proving that the initially treated condition was benign as opposed to a subsequent finding of malignancy. This while stating that the evidence of the diagnostic difference would be such that no further investigation would be necessary. The Court of Cassation states that since the alleged professional error was the failure to correctly identify the pathology, the defendant doctor “had to prove that the sebaceous cyst presented in such a way, as to exclude any doubt as to its nature.” This calls into question the chronological and/or topographical causal criteria invoked ex-post, because after a previous excision a recurrence or a new lesion at or near the scar is possible. However, in the absence of documentation that would have made it easy to follow the diagnostic process ex ante and sustain though description the benignity of the first dermatological diagnosis, the role of the histologic examination as an objective reference to confirm the nature of the disease comes to the fore. The defendant failed to demonstrate the initial professional compliance with the standard of care, in the face of a diagnosis of dermatofibrosarcoma.

Malignancies can occasionally develop in areas where benign conditions previously existed, which adds an additional layer of complexity to the diagnostic evaluation [28,29]. For example, a benign lesion can become malignant, or a scar can become the site of a new, unrelated malignancy. Certain types of scars, such as burn scars, have been linked to an elevated risk of malignancies, including squamous cell carcinoma. This may be due to local immune dysfunction caused by the scarring process itself [30,31]. Such events have also been described in the context of DFSP, even at the site of a previous surgical scar resulting from a skin biopsy or minor excision [32,33]. Therefore, the subsequent emergence of malignancy does not, per se, prove that malignancy was present at time T0 and that the clinician is negligent. Accordingly, the decisive evidence for appropriateness is the contemporaneous clinical record at T0 of the overall findings and their concordance, not an ex-post inference drawn from later events. Recognizing this scenario and its deficits, one might ask whether every lesion should be biopsied before treatment solely to pre-empt future doubt. We argue no: the standard is diagnostic appropriateness, not universal confirmatory testing.

For example, it would be impractical to suggest examining every wart histologically prior to cryotherapy or other destructive treatment, given that warts are typically identifiable by clear clinical and dermoscopic features. Therefore, requiring histological confirmation for every dermatological diagnosis would lead to unnecessary invasive procedures and complications without significant benefit to the patient [34]. The only effect would be to provide the physician with greater reassurance, which would distort the value of the specialist’s expertise [35].

Nevertheless, proper documentation and patient education regarding the nature of pathology and the necessity or appropriateness of histologic examination are critical. This is easier to achieve within a healthcare facility that has a health reporting system and patient clinical records. However, a private practice dermatologist is solely responsible for their own documentation to demonstrate proper performance and informed consent disclosure in the case of a claim [4].

In practice, a brief, structured note summarizing key lesion morphology, dermoscopic features (when present), differential diagnoses, recommended investigations, including advanced tests, and the rationale for the chosen management approach (e.g., conservative, surgical, excisional biopsy) is generally sufficient and legally compliant. Obviously, this must be adjusted according to the type of consultation provided, which is different in the case of a follow-up for a condition already confirmed than the first visit of a new patient. Moreover, when there is diagnostic uncertainty, and therefore the need for monitoring, further investigations, or specific diagnostic and therapeutic approaches, it is essential to provide the patient with at least a minimum amount of written information, even as free text within the report [36]. This helps strengthen the relationship of trust, the educational exchange, and the patient’s participation, thereby supporting a coherent and shared diagnostic process overall [37].

Regarding the second physician found liable, the diagnosis should have been re-evaluated if the clinical features were no longer consistent with the initial diagnosis of an epidermoid cyst, or in light of a recurrence/new lesion. This reevaluation is independent of specialty, depending on whether the supporting data has changed, even if specific competence is increasingly required in multifaceted or rare diseases [36]. Or when the physician does not have a dermatology specialty and is practicing based on experience alone [38]. Surgical excision based on a doubtful diagnosis without further investigation is clearly inappropriate because it may result in unnecessary and/or inappropriate surgery. Accordingly, reassessment or referral to specialized centers or professionals is indicated when features are atypical or discordant, and this decision should be explicitly recorded.

Questioning the reliability of a dermatologist’s diagnosis undermines the value of their training, experience, and commitment to continuous scientific updates. Assuming that every diagnosis must be confirmed by an objective test, such as histology, underestimates the importance of clinical experience. Conversely, making a histologic diagnosis the sole standard of confirmation is risky in complex cases where clinico-pathologic correlation is needed. In such cases, the clinician questions the histological result based on experience, starting with a clinical analysis [39].

Given the complexities and challenges highlighted, it is imperative that national scientific societies actively participate in medico-legal discourse. We encourage these societies to establish dedicated working groups to address these issues. In defining organizational models by pathology and overall healthcare services, as well as diagnostic and treatment standards up to the development of guidelines, it is essential to integrate medico-legal expertise to establish practice standards for adoption, while also providing training or exemplary formats to be applied in daily practice. These groups should bring together clinicians, forensic and legal experts, and policymakers to promote comprehensive understanding and ongoing education about the practical challenges dermatologists face.

4. Conclusions

The diagnostic process is ongoing, resulting from the clinician’s continuous effort to integrate experiential, semiological, instrumental, and dermato pathological data. This data must be communicated to the patient appropriately. A pathology with distinctive clinical or dermoscopic features that are clearly evident to the senses and reason may initially suggest a benign nature. If properly documented, such findings should not be questioned in principle. However, diagnostic uncertainty remains, even with accurate documentation and informed patient’s consent. Moreover, instrumental examinations, and, in particular, histopathological assessment, remain central to the overall diagnostic reasoning aimed at providing the best possible diagnostic hypothesis, while balancing the needs for sensitivity, specificity, patient safety, and professional competence.

By taking these steps, scientific societies can play a pivotal role in shaping a framework that supports and respects clinicians’ expertise in clinical and trial settings addressing comprehensively the key points of the diagnostic pathway.