Tumour necrosis is a valuable histopathological prognostic parameter in melanomas of the vulva and vagina.

Vulvar and vaginal melanomas (VVMs) are rare and aggressive malignancies with limited prognostic models available and there is no standard reporting protocol. VVMs were selected from six tertiary Canadian hospitals from 2000-2021, resected from patients aged ≥18 years, with 6 months or longer follow-up data, and confirmation of melanocytic differentiation by at least two immunohistochemical markers. Cases were reviewed by pathologists to identify histological biomarkers. Survival outcomes were tested with Kaplan-Meier log-rank, univariate Cox, and multivariate Cox regression. There were 79 VVMs with median follow-up at 26 months. Univariate analysis revealed that tumour necrosis, tumour ulceration, positive lymph nodes, and metastasis at diagnosis were significantly associated with disease-specific mortality, progression, and metastasis. Multivariate analysis identified tumour necrosis as an independent prognostic factor for disease-specific mortality (HR 4.803, 95% CI 1.954-11.803, p<0.001), progression (HR 2.676, 95% CI 1.403-5.102, p=0.003), and time-to-metastasis for non-metastatic patients at diagnosis (HR 3.761, 95%CI 1.678-8.431, p=0.001). Kaplan-Meier survival analyses demonstrated that tumour necrosis was a poor prognostic factor for disease-specific, progression-free, and metastasis-free survival (p<0.001 for all comparisons). Vaginal melanomas displayed decreased survival compared to vulvar or clitoral melanomas. This study identifies tumour necrosis as an independent prognostic factor for VVMs. Vaginal melanomas specifically showed worse survival outcomes compared to vulvar or clitoral melanomas, consistent with previously reported findings in the literature, emphasising the importance of differentiating between these primary tumour epicentres for prognostication and treatment planning in the care of genital melanoma patients.

The utility of SOX10 in mixed type desmoplastic melanoma with lymph node metastasis of the spindle cell component: A cautionary tale of inattentional blindness.

Desmoplastic melanoma (DM), a type of spindle cell melanoma separated into pure desmoplastic melanoma (PDM) and mixed desmoplastic melanoma (MDM) subtypes, can be a diagnostic challenge and easily confused for dermal scar, especially PDM. We report a 65-year-old white man who received a left thumb amputation after an initial biopsy for melanoma, an unclassified type with epithelioid morphology. The amputation and sentinel lymph node specimens were significant for residual melanoma with epithelioid morphology, dermal scar, and a slightly expanded "scar-like" capsular area in one of seven lymph nodes, which was diffusely positive for SOX10 on reflex sentinel lymph node immunohistochemical protocol. On re-review of the amputation "scar" like area, a subsequent SOX10 stain confirmed the diagnosis of MDM in this area with epithelioid and spindle cell morphology, significantly upgrading the tumor stage. We share this case to highlight: (i) MDM, although exceptionally uncommon, can result in a pure spindle cell lymph node metastasis, (ii) to encourage increased utilization of SOX10 to assess sentinel lymph node biopsies, especially in the context of melanomas with a spindle cell component, and (iii) share an example of inattentional blindness which was fortunately identified by reflex sentinel lymph node immunohistochemical protocols.

Moving towards the optimization of diagnosis for patients with sarcoma: A 10-year review of externally consulted sarcoma cases in a general anatomical pathology service.

INTRODUCTION: Soft tissue sarcomas (STS) are rare, diagnostically challenging, malignant tumors with diverse histomorphologic, immunohistochemical and molecular features. In our practice, STS are reported in a general anatomical pathology practice with no formal subspecialized training in reporting these complex specimens. Our study was performed to look at the rate of external consultation (EC), along with other parameters including discordance rate, associated diagnostic delay with EC and extent of secondary work-up performed by the consultant for correct diagnosis. METHODS: The reports from 880 soft tissue sarcomas cases in the province of Saskatchewan between January 1, 2010, and December 31, 2020, were analyzed descriptively. RESULTS: Of the 880 cases reviewed in our database, 51.9% (n = 457) cases were sent to 35 different North American institutions for expert opinion. The initial diagnosis and expert opinion were in full agreement for 182 cases (39.8%), while 194 cases (42.5%) had partial agreement and 66 cases (14.4%) had zero agreement. Of the cases that had zero agreement, 20 cases (4.4%) were initially diagnosed as malignant, with a benign opinion given by the expert; and 10 cases (2.2%) were initially diagnosed as benign, which were malignant upon expert review. CONCLUSION: Soft tissue sarcomas are complex tumors that frequently require expert opinion and integration of ancillary techniques with histomorphologic features for definitive classification. A multidisciplinary, subspecialized approach to STS and availability of necessary ancillary tests would improve diagnostic accuracy. In centers where the case load would not support the full-time expertise of an STS multidisciplinary team, criteria should be developed to effectively utilize EC practices.

Lichenoid granulomatous dermatitis: A case with dramatic desquamation and multiple potential causes.

Lichenoid granulomatous dermatitis, also known as giant cell lichenoid dermatitis, represents an uncommon mixed-pattern dermatitis with histopathologic features of interface dermatitis with band-like lymphocytic inflammation of the dermal-epidermal junction, with thinning of the epidermis or lichen planus-like changes, and granulomatous inflammation involving the dermis. Lichenoid granulomatous dermatitis can manifest with a variety of primary lesions and has various clinical associations. We present a challenging clinicopathologic case of lichenoid granulomatous dermatitis in a 58-year-old woman with dramatic cutaneous desquamation in the context of a complex medical history and multiple potential triggers.

Pigmented apocrine hamartoma: A distinct and uncommon pigmented lesion with dendritic melanocytes and appraisal of terminology.

A 20-year-old female presented to a gynecologist with an irregular, darkly pigmented, vulvar lesion. Histopathologic sections of a biopsy specimen showed cystically dilated glands with apical snouts, pigmented secretion, and numerous dendritic melanocytes. The lesion was diagnosed as a pigmented apocrine hamartoma of the vulva. We report the fifth case of this uncommonly encountered entity and discuss the conflicting terminology in the literature of this rare, pigmented lesion.

CDX2 and SATB2 positivity in pilomatrix carcinoma: Avoiding an erroneous diagnosis of cutaneous metastasis of gastrointestinal origin.

An 80-year-old female presented with a slowly growing 2-cm nodule on her shoulder over a 1-year period. Histopathologic sections of a biopsy specimen showed a multinodular, dermal-based basaloid tumor with areas of clear-cell change, stromal induction, as well as significant cytologic atypia and atypical mitotic activity. An initial investigation revealed positive staining of CDX2, a well-known marker of tumors of gastrointestinal origin. The case was referred to our dermatopathology service for consultation to determine if the lesion was in keeping with a cutaneous metastasis. On receipt of the case, an extended immunohistochemical panel was performed including SATB2, which displayed a similar pattern of staining as seen with CDX2. Although pathologists are most familiar with CDX2 and SATB2 as markers of gastrointestinal origin, the recent dermatopathology literature highlights that primary adnexal lesions of the skin also display positivity for CDX2 and can exhibit SATB2 positivity. We share a case of pilomatrix carcinoma with positive expression of nuclear CDX2 and SATB2, adding to the recent literature to (a) increase recognition of this staining pattern in hair follicle tumors, and (b) discuss briefly the shared molecular underpinnings in the tumorigenesis of gastrointestinal tumors and tumors of hair follicle origin that help clarify this underrecognized immunohistochemical pattern.

A Survey on Changes to the Canadian Anatomical Pathology Certification Examination Due to Coronavirus Disease 2019 and Implications for Competency-Based Medical Education.

The coronavirus disease 2019 pandemic resulted in a dramatic change in the Royal College of Physicians and Surgeons of Canada assessment process through elimination of the oral and practical components of the 2020 Anatomical Pathology examination. Our study sought to determine stakeholder opinions and experiences on these changes in the context of the 2019 implementation of competency-based medical education. Surveys were designed for residents and practicing pathologists. In total, 57 residents (estimated response rate 29%) and 185 pathologists (estimated response rate 19%) participated across Canada; 67% of pathologists disagreed with the 2020 Royal College examination changes, compared with 30% for residents (P = <.00001). When asked whether the Royal College examination should be eliminated, 95% of pathologists indicated they would be against this, compared to only 34% of residents (P = <.00001). Perceptions on changes to and importance of different components of assessment in competency-based medical education were similar between pathologists and residents, with participants perceiving assessment practices to have changed fairly little since its implementation, with the exception of more frequent feedback. Analysis of narrative comments identified several common themes around assessment, including the need for objectivity and standardization and the problem of failure-to-fail. However, residents identified numerous elements of their performance that can be assessed only through longitudinal evaluation. Pathologists, on the other hand, tended to view these aspects of performance as laden with bias. Our results will hopefully help guide future innovation in assessment by characterizing different stakeholder perspectives on key issues in medical education.

A case report of a localized reticular erythematous mucinosis like eruption of the lower legs mimicking cutaneous larvae migrans.

Reticular erythematous mucinosis is an uncommon type of cutaneous mucinosis. Typically, reticular erythematous mucinosis affects middle-aged women and usually appears as papules and plaques on the mid-upper trunk. Histologically, biopsies of reticular erythematous mucinosis reveal increased deposition of dermal mucin and perivascular lymphocytic inflammation. Infrequently, reticular erythematous mucinosis has been reported in males and in atypical locations other than the trunk. In these instances, reticular erythematous mucinosis can present a diagnostic challenge clinically and histologically. This case describes the clinical and histologic findings of a localized variant of reticular erythematous mucinosis in a 65-year-old male patient.

A case of multifocal cutaneous alternariosis in a patient with hairy cell leukemia.

We present a case of multifocal cutaneous alternariosis in a 69-year-old man with hairy cell leukemia. The patient presented with painful, violaceous nodules of the lower extremities and left forearm. His physical examination was otherwise normal. Biopsy specimens were submitted first for histopathological examination, followed by microbiological testing. Histopathology showed epidermal hyperplasia, intraepidermal abscess formation, and intracellular and extracellular fungal elements. Subsequent microbiological investigations, including fungal culture and polymerase chain reaction (PCR), isolated Alternaria alternata. The patient was treated for cutaneous alternariosis with itraconazole for 12 weeks and demonstrated significant improvement of the lesions. This case highlights the role of dual histopathological and microbiological laboratory investigation in suspected opportunistic cutaneous mycoses.

Les chercheurs présentent un cas d'alternariose cutanée multifocale chez un homme de 69 ans atteint d'une leucémie à tricholeucocytes. Le patient a consulté à cause de nodules violacés et douloureux sur les extrémités inférieures et l'avant-bras gauche. Son examen physique était autrement normal. Des biopsies ont été d'abord soumises en vue d'un examen histopathologique, puis de tests microbiologiques. L'histopathologie a révélé une hyperplasie épidermique, la formation d'abcès épidermiques et des éléments fongiques intracellulaires et extracellulaires. Les explorations microbiologiques subséquentes, y compris les cultures fongiques et l'amplification en chaîne par polymérase, ont isolé l'Alternaria alternata. Le patient a reçu un traitement de 12 semaines à l'itraconazole pour vaincre une alternariose cutanée, et ses lésions ont considérablement diminué. Ce cas souligne l'intérêt de conjuguer l'exploration histopathologique à l'exploration microbiologique dans les cas présumés de mycose opportuniste.

Bullous leukemia cutis: a rare clinical subtype.

Leukemia cutis represents infiltration of the skin by malignant leukocytes and typically presents as firm, red-brown papules and nodules. The bullous clinical subtype is considered a rare entity and can be a diagnostic challenge. This case describes a patient with bullous leukemia cutis mimicking vesiculobullous skin disease.

Is focal active colitis of greater clinical significance in pediatric patients? A retrospective review of 68 cases with clinical correlation.

Focal active colitis (FAC) is a histopathologic finding of uncertain clinical significance in individual patients. In adults, infection accounts for approximately 50%, Crohn's disease (CD) for 0-13%, and 20%-30% are idiopathic. One previous study of 29 cases of pediatric FAC showed a 28% rate of CD. This study reviewed a larger cohort of pediatric patients to determine what proportion had IBD, and whether an amount or pattern of inflammation could predict IBD. Sixty-eight patients aged ≤18years with FAC were identified and reviewed. Patients with a prior diagnosis of IBD or chronic colitis in the index biopsies were excluded. Slides were assessed for a number of inflammatory criteria. Clinical data and final diagnoses were recorded. Data were analyzed using Pearson correlations and Fisher's exact χ2 analyses. Sixteen patients (24%) had a final diagnosis of IBD. When cases with terminal ileal (TI) inflammation were excluded, 6 of 54 patients had a final diagnosis of IBD (11%). A final diagnosis of IBD was significantly associated with crypt abscesses and elevated serum inflammatory markers. IBD was significantly associated with TI inflammation. An amount or pattern of inflammation that could be used to predict IBD was not determined. This study demonstrated a 24% rate of IBD in pediatric patients with FAC; however, when patients with associated TI inflammation were excluded, the rate was 11%, similar to reported rates in adults. FAC in pediatric patients without terminal ileal inflammation does not appear to warrant more aggressive follow-up.

Endobronchial Carcinoid Tumour with Extensive Ossification: An Unusual Case Presentation.

Carcinoid tumour is a well-known primary endobronchial lung neoplasm. Although calcifications may be seen in up to 30% of pulmonary carcinoid tumours, near complete ossification of these tumours is an unusual finding. Such lesions can prove diagnostically challenging at the time of intraoperative frozen section as the latter technique requires thin sectioning of the lesion for microscopic assessment. We present an unusual case of endobronchial carcinoid tumour with extensive ossification in a 45-year-old male. Preliminary intraoperative diagnosis was achieved through the alternative use of cytology scrape smears. The final diagnosis was confirmed after decalcification of the tumour. The prognostic implications of heavily ossified carcinoid tumours remain elusive. Long-term clinical follow-up of these patients is recommended.

Interobserver variability in assessing dysplasia and architecture in colorectal adenomas: a multicentre Canadian study.

AIMS: Following the introduction of colorectal cancer screening programmes throughout Canada, it became necessary to standardise the diagnosis of colorectal adenomas. Canadian guidelines for standardised reporting of adenomas were developed in 2011. The aims of the present study were (a) to assess interobserver variability in the classification of dysplasia and architecture in adenomas and (b) to determine if interobserver variability could be improved by the adoption of criteria specified in the national guidelines. METHODS: An a priori power analysis was used to determine an adequate number of cases and participants. Twelve pathologists independently classified 40 whole-slide images of adenomas according to architecture and dysplasia grade. Following a wash-out period, participants were provided with the national guidelines and asked to reclassify the study set. RESULTS: At baseline, there was moderate interobserver agreement for architecture (K=0.4700; 95% CI 0.4427 to 0.4972) and dysplasia grade (K=0.5680; 95% CI 0.5299 to 0.6062). Following distribution of the guidelines, there was improved interobserver agreement in assessing architecture (K=0.5403; 95% CI 0.5133 to 0.5674)). For dysplasia grade, overall interobserver agreement remained moderate but decreased significantly (K=0.4833; 95% CI 0.4452 to 0.5215). Half of the cases contained high-grade dysplasia (HGD). Two pathologists diagnosed HGD in ≥75% of cases. CONCLUSIONS: The improvement in interobserver agreement in classifying adenoma architecture suggests that national guidelines can be useful in disseminating knowledge, however, the variability in the diagnosis of HGD, even following guideline review suggests the need for ongoing knowledge-transfer exercises.