Agreement between histological subtype on punch biopsy and surgical excision in primary basal cell carcinoma

Background Diagnosis of clinically suspected basal cell carcinoma (BCC) by histological confirmation with punch biopsy has been recommended before treatment. Even shave biopsy has been proposed as useful to predict the correct subtype in primary BCC in 76–81%, whereas the agreement between histological BCC subtype on punch biopsy and subsequent excision specimens in recurrent BCC is 67.1%. However, no large studies on the agreement between histological BCC subtype seen on punch biopsy and the following surgical excision are performed in primary BCC. Objective The aims of this study were (i) to establish the agreement between histological BCC subtype on punch biopsy and the subsequent surgical excision of primary BCC and; (ii) to investigate the proportion of primary BCCs in which punch biopsy enables identification of the most aggressive growth pattern. Methods Retrospective analyses of 243 primary BCCs with both punch biopsy and subsequent surgical excision. Analyses were based on the most aggressive histological subtype of the tumour. Results The agreement between BCC subtype on punch biopsy and the subsequent surgical excision of primary BCCs was 60.9%. A punch biopsy can predict the most aggressive growth pattern of primary BCCs in 84.4%. Seventy‐four percentage of all primary BCCs consisted of more than one histological subtype. Conclusion Dermatologists and other physicians have to be aware of the limited diagnostic value of a punch biopsy to determine the histological BCC subtype of the whole lesion. Misdiagnosis of the subtype will lead to undertreatment in one of six primary BCCs.     

High discordance between punch biopsy and excision in establishing basal cell carcinoma subtype: analysis of 500 cases

Background Basal cell carcinoma (BCC) is the most frequently occurring cancer in humans. Worldwide incidences rise about 10% each year, increasing the burden on dermatologists, general practitioners and pathologists as well as increasing costs for the health care system. Increasingly non‐surgical treatment options are used in the treatment of BCC, without histological confirmation of BCC subtype, potentially resulting in under‐treatment. Objective We evaluated the diagnostic accuracy of a punch biopsy for the BCC histological subytpe in a primary BCC and the prevalence of biopsy‐based under‐diagnosis of aggressive subtypes. Accuracy of a punch biopsy was defined as concordance of the diagnosis of subtype of BCC at punch biopsy and excision. Methods A retrospective chart‐review was performed of primary BCC, which were proven by punch biopsy and subsequently treated by excision. The first 100 consecutive BCCs per year during the years 2004–2009 were included, yielding a total of 500 evaluated BCCs. Results The overall accuracy of punch biopsy for BCC subtype at excision was 69%, in single‐type BCC 83% (n = 343) and in mixed‐type BCC 37% (n = 157). Accuracy varied substantially according to BCC subtype, being highest in the superficial subtype (84%) and subsequently in infiltrative (69%), nodular (63%) and micronodular subtype (38%). In 11% of all cases, an unsuspected more aggressive subtype was present. Conclusion Punch biopsy has a high accuracy in single‐type BCCs and a considerably lower accuracy in mixed‐type BCCs for establishing BCC subtype compared to excision. The presence of an unsuspected aggressive subtype could explain therapy failure of non‐surgical treatments like imiquimod or photodynamic therapy.     

Pre-treatment evaluation of basal cell carcinoma for photodynamic therapy: comparative measurement of tumour thickness in punch biopsy and excision specimens

Tumour thickness affects the outcome of photodynamic therapy in basal cell carcinoma (BCC). The aim of this study was to evaluate whether punch biopsy provides reliable information on BCC tumour thickness, by comparing corresponding measurements in biopsy and excision specimens for 48 lesions in 43 patients. BCC tumours were between 0.2 and 6.1 mm thick. The mean depth of the excisions were 0.14 mm greater than that of the biopsies. Bland-Altman 95% limits of agreement were (-1.3, 1.6) mm, but the difference between measurements increased with tumour thickness. A punch biopsy tumour thickness of 1.0 mm yielded an upper 95% predicted limit for excision depth within 2.0 mm. In conclusion, there was reasonable overall agreement between corresponding measurements. A biopsy thickness of 1.0 mm suggests that the tumour will most likely be within the current accepted limits for photodynamic therapy. With increasing tumour thickness, however, individual tumour measurements may differ considerably.     

Basal cell carcinoma: a comparison of shave biopsy versus punch biopsy techniques in subtype diagnosis.

BACKGROUND: There are two standard ways to obtain tissue for histologic classification of a clinically suspected basal cell carcinoma: shave and punch biopsy. However, information on the value of each method is limited. OBJECTIVE: The purpose of this study was to identify accuracy rates of two standard biopsy techniques in diagnosing subtypes of basal cell carcinoma. METHODS: A total of 86 cases were identified that had received either a punch or a shave biopsy with subsequent total excision of tumor. The biopsy specimens and excisions were compared for histologic correlation. RESULTS: Analysis of specimens from punch and shave biopsies produced equivalent diagnostic accuracy rates: 80.7% and 75.9%, respectively. There was no statistically significant tendency to overcall or undercall any particular tumor subtype on the basis of the type of biopsy procedure used. CONCLUSION: For histologic classification of basal cell carcinoma, there is an approximately 80% accuracy rate with both the shave and the punch biopsy. Therefore either biopsy technique is appropriate.     

Interrater and intrarater agreement of confocal microscopy imaging in diagnosing and subtyping basal cell carcinoma

Background

Reflectance confocal microscopy (RCM) imaging can be used to diagnose and subtype basal cell carcinoma (BCC) but relies on individual morphologic pattern recognition that might vary among users.

Objectives

We assessed the inter‐rater and intrarater agreement of RCM in correctly diagnosing and subtyping BCC.

Methods

In this prospective study, we evaluated the inter‐rater and intrarater agreement of RCM on BCC presence and subtype among three raters with varying experience who independently assessed static images of 48 RCM cases twice with four‐week interval (T1 and T2). Histopathologic confirmation of presence and subtype of BCC from surgical excision specimen was defined as the reference standard.

Results

The inter‐rater agreement of RCM for BCC presence showed an agreement of 82% at T1 and 84% at T2. The agreements for subtyping BCC were lower (52% for T1 and 47% for T2). The intrarater agreement of RCM for BCC presence showed an observed agreement that varied from 79% to 92%. The observed agreements for subtyping varied from 56% to 71%.

Conclusions

In conclusion, our results show that RCM is reliable in correctly diagnosing BCC based on the assessment of static RCM images. RCM could potentially play an important role in BCC management if accurate subtyping will be achieved. Therefore, future clinical studies on reliability and specific RCM features for BCC subtypes are required.     

Metastatic basal cell carcinoma diagnosed by sentinel lymph node biopsy

Although commonly used in the treatment of melanoma, sentinel lymph node biopsy has not yet been successfully used to detect lymphatic metastasis of basal cell carcinoma because of exceedingly low rates of metastasis. We describe the use of lymphatic mapping and sentinel lymph node biopsy in a patient after basal cell carcinoma was identified within a lymphatic vessel in the primary excisional specimen. As a result, the patient was found to have clusters of basal cell carcinoma in a sentinel lymph node resected from the right deltopectoral groove. Although metastatic basal cell carcinoma is exceedingly rare, we conclude that sentinel lymph node biopsy may be useful for certain high-risk lesions, such as lesions demonstrating histologic evidence of lymphatic invasion. Further experience is necessary to determine the clinical usefulness of sentinel node biopsy in these patients and its effect on patient survival.     

Diagnostic accuracy of dermoscopy for 934 basal cell carcinomas: A single-center retrospective study

Although the efficacy of dermoscopic diagnosis of basal cell carcinoma (BCC) has already been established, most studies have been conducted in Western countries. However, there are racial differences in the clinicopathological characteristics of BCC, highlighting the need for a survey among Asians. Herein, we aimed to investigate the diagnostic accuracy of dermoscopy in 934 Japanese patients with BCC and statistically analyze the clinicopathological factors affecting diagnostic accuracy. We analyzed 5093 skin lesions, including 934 BCCs that were diagnosed consecutively from 1998 to 2018. The sensitivity and specificity of dermoscopic diagnosis for BCC were calculated. The sensitivity and specificity of dermoscopic diagnosis were 92.2% and 96.0%, respectively. There were 73 false-negative cases of BCCs that were clinically diagnosed with other diseases. The most common incorrect clinical diagnosis was seborrheic keratosis (n = 18), followed by melanocytic nevus (n = 15). Multiple logistic regression analysis showed that sensitivity was significantly lower in BCCs located on the trunk and extremities, which showed low pigmentation (less than 10% of the lesion surface) and were diagnosed by a resident dermatologist. Experience of 3–6 months of 12 resident dermatologists revealed increased sensitivity. Dermoscopy is a reliable tool for the accurate diagnosis of BCC in Japanese individuals. Care should be taken when diagnosing BCCs of the trunk and extremities, and the less-pigmented subtype because of lower sensitivity. A certain amount of experience is required to improve the skills for dermoscopy.     

Infiltrative basal cell carcinoma occurring in sites of biopsy-proven nodular basal cell carcinoma

Over 200 basal cell carcinomas (BCCs) are biopsied and subsequently excised each year at the Veterans Affairs Palo Alto Health Care System (VAPAHCS). A focal infiltrative pattern developed in the region of the biopsy scar in the re-excision specimens of 20 cases out of approximately 400 BCCs (< 5%) examined histopathologically over a 2-year period. The patient population included predominantly male, elderly Caucasians (mean age 71), and all tumors fulfilled clinical and histologic criteria for nodular BCC at the time of initial punch or shave biopsy. No patient showed recurrence of tumor following simple re-excision with 2–3 mm surgical margins, with a mean follow up of 25.4 months after excisional surgery. These neoplasms had a more benign clinical course, possibly related to scar formation in healing sites of previously biopsied nodular BCC, rather than true aggressive-growth BCC. The authors conclude that a focal infiltrative pattern in a re-excision specimen may occur histologically as a scar-induced pattern which mimics an aggressive-growth BCC, but does not appear to have the same prognosis. We believe this is an important histologic observation, as recognition of biopsy scar changes in an excisional specimen of BCC may help to distinguish it from true aggressive-growth BCC.     

Immunohistologic differential diagnosis of basal cell carcinoma, squamous cell carcinoma, and trichoepithelioma in small cutaneous biopsy specimens

The distinction between squamoid basal cell carcinoma and basaloid squamous cell carcinoma (or between BCC and trichoepithelioma variants) is usually made readily on the basis of defined histological criteria. However, these differential diagnoses occasionally can pose difficult morphological problems. The stated distinctions are clinically important because the risk of progressive disease is significantly higher with squamous carcinoma of the skin than with basal cell carcinoma (BCC), and a trichoepithelioma misinterpreted as BCC burdens the patient with an inaccurate diagnosis that may result in inappropriate surgery. Recent reports have suggested that reactivity with the monoclonal antibody Ber-EP4 is capable of separating histologically similar basal cell and squamous carcinomas, and that ihe expression of bcl-2 or CD34 antigen is able to distingtush BCC from trichoepithelioma. However, corroborative studies of these contentions are few in number. In order to investigate the usefulness of the stated immunostains in the above-cited differential diagnoses, the authors analyzed 45 basal cell carcinomas and 22 squamous carcinomas, as well as 36 trichoepitheliomas. The monoclonal antibodies Ber-EP4, My10 (CD34), and anti-bcl-2 were applied to formalin-fixed paraffin sections in all cases, using a standard avidin-biotin-peroxidase complex method. Most BCCs demonstrated strong, diffuse cytoplasmic labeling with Ber-EP4 and anti-bcl-2. In contrast, the squamous carcinomas were uniformly negative for the former marker and only focally reactive for the latter in four examples. ‘Peripheral’bcl-2 staining of trichoepitheliomas was noted in 24 of 33 of the immunoreactive tumors, but the remainder were marked diffusely and similarly to most BCCs. Among the latter, immature trichoepitheliomas were diffusely reactive for this marker in 6 of 8 cases. Labeling of epithelium for CD34 failed to discriminate between any of the tumor types under evaluation, whereas staining of peritumoral stroma was characteristic of the majority of trichoepitheliomas and more than one-third of metatypical basal cell carcinomas. These data support the suggestion that Ber-EP4 and bcl-2 are useful in the separation of BCC from squamous carcinomas. Nevertheless, they also serve to caution against reliance upon bcl-2 and CD34 immunostains in attempting to distinguish BCC from trichoepithelioma in histologically enigmatic cases. There is currently no certain method other han conventional microscopy that can be applied successfully to the latter problem.     

Comparison of basal cell carcinoma subtypes observed in preoperative biopsy and Mohs micrographic surgery

BackgroundThe treatment of basal cell carcinoma depends on its histological subtype. Therefore, a biopsy should be performed before definitive treatment. However, as the biopsy is only a sample of the tumor, it does not always shows every histological subtype present in the neoplasm. Few studies have compared the histological findings of biopsies with the findings of Mohs micrographic surgery. By evaluating the totality of the peripheral margins, in addition to sampling large tumor areas, this technique provides a more representative amount of tissue than preoperative biopsy.Objectivesa) Determine the agreement between the histological subtype of basal cell carcinoma from punch biopsy and the findings of Mohs surgery; b) To assess, among the discordant cases, the prevalence of non-aggressive tumors in the preoperative biopsy that were reclassified as aggressive by Mohs surgery.MethodsRetrospective analysis of 79 cases of basal cell carcinomas submitted to punch biopsy and subsequent Mohs surgery.ResultsThe agreement between the classification of the subtypes in the biopsy and in Mohs surgery was 40.5%. Punch biopsy was able to predict the most aggressive basal cell carcinoma growth pattern in 83% of cases.Study limitationsRetrospective nature, sample size, and biopsies performed by different professionals.ConclusionsThe agreement between the histopathological subtypes of basal cell carcinoma as seen in preoperative biopsy and Mohs surgery was low. However, preoperative biopsy presented good accuracy (83%) in detecting aggressive histopathological subtypes.     

Granular cell basal cell carcinoma

Granular cell basal cell carcinoma (BCC) is a rare histologic variant of BCC. In this, the third reported case, the tumor consisted almost entirely of granular cells. By electron microscopy, these cells were filled with pleomorphic lysosome-like granules lined by unit membranes and containing homogeneous or granular electron-dense bodies, membranous debris and amorphous material. The epithelial origin of the tumor was suggested by the characteristic light microscopic appearance of tumor cell islands with some areas of peripheral palisading, and was confirmed by electron microscopic features of numerous well-formed pentalaminate desmosome junctions and sparse cytoplasmic tonofilament bundles, some of which showed attachments to the desmosomes. Histochemical immunoperoxidase stains for lysozyme showed no cytoplasmic lysozyme activity, in common with other granular cell tumors, but ultrastructural examination did not reveal angulate bodies, in contrast to findings in non-epithelial granular cell tumors.     

Granular cell basal cell carcinoma

A 69-year-old woman presented with a 2-year history of a slowly growing tumour on the nose. The clinical diagnosis was basal cell carcinoma (BCC) and a complete excision was performed. Histologically, the tumour had the general features of a BCC but with sheets and nests of cells with granular cytoplasmic changes in the centre of the lesion. A pathological diagnosis of granular cell BCC was made. On immunohistochemical examination, the tumour cells were Ber-EP4, cytokeratin AE1/AE3 and cytokeratin CAM 5.2 positive but S100 protein negative. Only the granular cells were CD68 antigen (monoclonal antibody KP1) positive.