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.

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.

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.

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.

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.

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.

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.

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.

Motorized cart driver safety in assisted living

When a group of residents at a life care facility purchased motorized carts to move around the 350,000-square-foot facility, staff members were faced with the need to ensure the safety of both drivers and pedestrians. This article describes a safety assessment procedure developed for cart drivers who lived in the assisted living area of the community. Five performance criteria were selected for the safety assessment: the ability to safely moving into and out of the vehicle, demonstrate safe reaction times, take appropriate evasive action to sudden obstructions in the driver's path, turn the vehicle around safely, and park the vehicle without hitting walls or other objects.