The clinico-pathological spectrum of plaque-type blue naevi and their potential for malignant transformation.

AIMS: Plaque-type blue naevi are rare melanocytic tumours presenting as large, pigmented plaques at birth or during childhood. There is a risk for malignant transformation, but no larger comprehensive studies exist and the diagnosis is challenging, especially on limited biopsy material. The aim is to describe the clinicopathological features and behaviour of the disease more comprehensively. METHODS AND RESULTS: We retrieved eight plaque-type blue naevi, presenting as large, pigmented plaques (median = 7 cm; range = 3-26) most frequently affecting the scalp (four) followed by the cheek, arm, abdominal wall and gluteal cleft (one each), with a slight female predilection. Median age at time of biopsy was 39.5 years (range = 15-90), but three tumours had been present at birth and one since childhood. Histopathologically, the tumours were poorly circumscribed and composed of cellular fascicles of uniform spindle cells in a background of variably prominent pigmented dendritic cells affecting dermis and subcutaneous tissues. The majority had mutations in GNAQ. One tumour showed malignant transformation, characterised by an expansile nodule of pleomorphic epithelioid melanocytes with rhabdoid morphology, high mitotic activity and areas of necrosis. This patient developed metastatic melanoma to lymph nodes. All patients are alive with a median follow-up of 60 months. CONCLUSION: Plaque-type blue naevi are diagnostically challenging tumours with risk for malignant transformation. Awareness and familiarity with the salient clinicopathological features are necessary for reliable diagnosis, and long-term clinical follow-up is required to monitor for malignant transformation.

Ulcerated CRTC1::TRIM11 cutaneous tumor with metastases.

CRTC1::TRIM11 cutaneous tumor (CTCT) is a rare skin tumor of uncertain differentiation. In the 49 reported cases, only four cases showed regional or distant metastasis, but follow-up remains limited. Herein, we present a case of metastatic CTCT with ulceration, a histological feature that has not been previously described. A 75-year-old male with a 2-month history of toe ulceration underwent a shave biopsy, which showed a dermal nodular neoplasm that was immunoreactive for SOX10 and S100, negative for Melan-A, and was initially diagnosed as melanoma. Upon pathology review at our institution, the tumor was composed of intersecting fascicles and nests of epithelioid and spindle cells. Additional immunohistochemistry revealed immunoreactivity of the tumor for MiTF and NTRK and negativity for HMB-45 and PRAME. Next-generation sequencing identified CRTC1::TRIM11 fusion, leading to a revised diagnosis of CTCT. The patient proceeded to a toe amputation and sentinel lymph node (SLN) biopsy 5 months after the shave biopsy. The amputation showed residual CTCT and a focus on lymphovascular invasion. The SLN revealed multifocal subcapsular metastases. The patient was started on adjuvant nivolumab and showed biopsy-proven recurrence in the right inguinal lymph nodes and imaging findings suspicious for pulmonary metastases 8 months after the excision. In summary, we present a case of CTCT with ulceration and lymphovascular invasion. We also provide additional evidence that a subset of CTCT behaves aggressively. The optimal surgical and medical treatments are unknown.

Isolated Pulmonary Emergomycosis in an Immunocompetent Patient in Alberta, Canada.

Emergomyces canadensis pulmonary infection was incidentally diagnosed in an asymptomatic patient suspected to have metastatic osteosarcoma. Molecular diagnosis was imperative to fungal identification given overlapping histopathological features with histoplasmosis. This report documents a case of isolated pulmonary emergomycosis in an otherwise immunocompetent patient while discussing diagnostic and management pitfalls of this emerging and underdiagnosed infection.

Analysis of penetrating keratoplasty in Northern Alberta, Canada, from 2000 to 2015.

OBJECTIVE: To study indications for penetrating keratoplasty (PK) at a single site. The trends in the causative organisms for infectious keratitis requiring surgery were also evaluated. DESIGN: Retrospective observational study. PARTICIPANTS: A total of 1181 eyes of 935 patients undergoing PK between January 2000 and December 2015 in Northern Alberta, Canada. METHODS: Indications for PK were evaluated over the 16-year study period, and the trends in these indications were compared over 5-year intervals. The microbiology of infectious keratitis cases requiring surgery was similarly evaluated. RESULTS: The most common indications for PK from 2000 to 2015 were keratoconus (23%), re-graft (22%), and corneal scar (12%). There was a decline in the percent of total surgeries done for Fuchs' dystrophy (p = 1.1 × 10-3) and pseudophakic bullous keratopathy (p = 5.6 × 10-5), whereas a corresponding increase in keratoconus (p = 3.2 × 10-5), trauma (p = 2.1 × 10-3), and infectious keratitis cases (p = 0.010) was observed. The most common causes for infectious keratitis cases were viral (45%), bacterial (18%), parasitic (11%), and fungal (9%). There was a significant increase in the percent of infectious keratitis cases due to a viral etiology from 2005 to 2010 (p = 6.4 × 10-3). CONCLUSIONS: The indications for PK are comparable with other centres in North America. Nearly half of all infectious keratitis cases requiring surgery are viral. The increase in viral cases requiring surgery may reflect improved diagnostics or recurrent cases.

Microperimetry as an Outcome Measure in Choroideremia Trials: Reproducibility and Beyond.

PURPOSE: To determine test-retest repeatability of microperimetry testing (MP) in choroideremia (CHM) subjects using standard and personalized stimulus grids. METHODS: Fifteen CHM subjects (28 eyes) underwent consecutive repeat examinations with the Macular Integrity Assessment (MAIA) microperimeter using a standard (10°) and a customized macular grid adapted to individual macular pathology. Repeatability of standard-grid mean (MS) and point-wise (PWS) sensitivity was determined and compared with age-matched controls (seven eyes), with PWS separately analyzed for loci within and outside the border of degeneration. Interpolated volumetric indices were used to estimate repeatability of customized grids and compare their performance to standard grids. RESULTS: Test-retest measures of standard-grid MS yielded higher coefficients of variation (CV) in CHM subjects compared with controls (0.09 vs. 0.02). Volumetric indices from customized grids improved repeatability by driving CV values to 0.05 and close to 0.02 for region-of-interest (ROI) analysis. Variability of PWS was significantly higher in CHM, especially at the border of degeneration (10.68 vs. 4.74 dB at the central retina, P < 0.001). CONCLUSIONS: Microperimetry testing in CHM shows high test-retest variation at the border of degeneration, which influences repeatability of MS measures. Volumetric measures from customized grids can improve reliability of both global and regional sensitivity assessment. Nevertheless, inherent test-retest variation of individual points needs to be taken into account when assessing potential functional decline and/or disease progression.