Incidental detection of non-melanoma neoplasms in sentinel lymph node biopsy for melanoma staging: A retrospective case series.

BACKGROUND: Patients with malignant melanoma have an increased risk of developing secondary hematologic malignancy, and patients with hematologic malignancies have an increased risk of developing melanoma. Rarely, sentinel lymph node biopsies (SLNBs) collected for melanoma staging might harbor lymphoma or even carcinoma, which may represent a second primary malignancy (SPM). Biopsied lymph node(s) might serve as the first site of recognition for a SPM. Yet, there has been little systematic investigation regarding the characteristics of incidental SPMs detected on SLNB for melanoma staging. METHODS: A series of cases of lymphomas and carcinomas were detected incidentally during SLNB for melanoma staging from two tertiary academic centers between 2000 and 2021. RESULTS: Fifteen cases of incidentally detected SPMs were reviewed, comprising 12 lymphomas and three carcinomas. The most common incidentally detected second malignancy was chronic lymphocytic leukemia/small lymphocytic lymphoma (60%, 9/15). There were three cases of incidentally detected metastatic carcinoma. Of all incidentally detected malignancies, 2/3 carcinomas and 4/12 lymphomas represented first-time diagnoses of SPM in a melanoma patient. Forty percent of cases (6/15) also harbored metastatic melanoma in the sentinel lymph node. CONCLUSIONS: It is possible to incidentally detect SPMs in SLNBs for melanoma staging. Early detection of SPMs in melanoma patients has implications for the treatment of both incidental SPM and melanoma.

Cutaneous Collagenous Vasculopathy: A Short Case Series and Literature Review.

ABSTRACT: Cutaneous collagenous vasculopathy (CCV) is a rare and idiopathic microangiopathy of superficial dermal blood vessels. There have been 75 cases described in the literature to date, not including the current report; however, given its clinical similarity to other primary telangiectasias, it is likely to be underreported and underdiagnosed. Here, we describe the clinical and histological features of 2 patients we newly diagnosed with CCV. Both generally fit the profile of prior cases and confirm previously described associations-they both are older White women, have rashes on their lower extremities, and have conditions and medications that are common among other reported cases. However, both are also somewhat atypical, as Patient 1 had symptomatic CCV and Patient 2 had a papular rash. As such, both cases broaden the spectrum of our current understanding of CCV. We also provide a comprehensive review of all published reports of CCV to date and uncover 2 previously unreported associations: one with visceral malignancy, and the other with hypothyroidism. Whether these association are coincidental is worth investigating in future studies.

Deep learning generates synthetic cancer histology for explainability and education.

Artificial intelligence methods including deep neural networks (DNN) can provide rapid molecular classification of tumors from routine histology with accuracy that matches or exceeds human pathologists. Discerning how neural networks make their predictions remains a significant challenge, but explainability tools help provide insights into what models have learned when corresponding histologic features are poorly defined. Here, we present a method for improving explainability of DNN models using synthetic histology generated by a conditional generative adversarial network (cGAN). We show that cGANs generate high-quality synthetic histology images that can be leveraged for explaining DNN models trained to classify molecularly-subtyped tumors, exposing histologic features associated with molecular state. Fine-tuning synthetic histology through class and layer blending illustrates nuanced morphologic differences between tumor subtypes. Finally, we demonstrate the use of synthetic histology for augmenting pathologist-in-training education, showing that these intuitive visualizations can reinforce and improve understanding of histologic manifestations of tumor biology.

An Update on Endocrine Mucin-producing Sweat Gland Carcinoma: Clinicopathologic Study of 63 Cases and Comparative Analysis.

Endocrine mucin-producing sweat gland carcinoma (EMPSGC) is a rare, low-grade adnexal neoplasm with predilection for the periorbital skin of older women. Histologically and immunophenotypically, EMPSGC is analogous to another neoplasm with neuroendocrine differentiation, solid papillary carcinoma of the breast. Both lesions are spatially associated with neuroendocrine mucinous adenocarcinomas of the skin and breast, respectively. EMPSGC is ostensibly a precursor of neuroendocrine-type mucinous sweat gland adenocarcinoma (MSC), a lesion of uncertain prognosis. Non-neuroendocrine MSC has been deemed locally aggressive with metastatic potential, and previous works speculated that EMPSGC-associated (neuroendocrine-type) MSC had similar recurrence and metastatic potential with implications for patient follow-up. Only 96 cases of EMPSGC have been reported (12 cases in the largest case series). Herein, we present 63 cases diagnosed as "EMPSGC" in comparison with aggregated results from known published EMPSGC cases. We aim to clarify the clinicopathologic features and prognostic significance of the neuroendocrine differentiation of EMPSGC and its associated adenocarcinoma and to determine the nosological relevance of EMPSGC association in the spectrum of MSC histopathogenesis. Results established an overall female predominance (66.7%) and average presenting age of 64 years. EMPSGC lesions were associated with adjacent MSC in 33.3% of cases. The recurrence rate for neuroendocrine-type MSC was ~21%, less than the reported 30% for non-neuroendocrine MSC. There were no cases of metastasis. EMPSGC and neuroendocrine-type MSC are distinct entities with more indolent behavior than previously reported, supporting a favorable prognosis for patients.

ALTERED PARAFOVEAL MICROVASCULATURE IN TREATMENT-NAIVE CHOROIDAL MELANOMA EYES DETECTED BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To determine whether parafoveal microvascular changes have occurred in choroidal melanoma eyes before radiotherapy. METHODS: A retrospective cohort study included 30 consecutive patients with unilateral choroidal melanoma. The microvascular structure was analyzed by optical coherence tomography angiography. Fellow eyes served as control for affected eyes. RESULTS: Optical coherence tomography angiography demonstrated no difference in superficial foveal avascular zone (P = 0.316), but showed significant enlargement in deep foveal avascular zone (P < 0.0001) in affected eyes as compared with fellow eyes. It also showed significant decrease in superficial (P = 0.004) and deep (P = 0.0003) capillary vascular density (CVD). In subgroup analyses, the presence of subretinal fluid contributed to significant enlargement of deep foveal avascular zone (P < 0.0001) as well as reduction in superficial (P = 0.0001) and deep (P = 0.001) CVD. By linear regression, greater tumor diameter correlated with reduction in deep CVD (y = -0.42x + 1.01, Pslope = 0.021); greater tumor thickness correlated with reduction in both superficial (y = -0.67x + 0.24, Pslope = 0.039) and deep (y = -0.82x + 0.56, Pslope = 0.002) CVD. CONCLUSION: Optical coherence tomography angiography documented significant enlargement of deep foveal avascular zone as well as reduction in superficial and deep CVD in affected eyes. These findings correlated with the presence of subretinal fluid and increasing tumor size, suggesting that tumor-related factors contribute to parafoveal microvascular ischemia.