Ultrastructure of lentigo maligna in the oral cavity

A rare case of lentigo maligna in the oral cavity was investigated by light and electron microscopy. Cutaneous lentigo malignas often develop to malignant melanomas. However, the electron microscopic examination revealed that even though there were a large number of melanosomes, most of them were late stage and had membrane structure, and positive staining with HMB-45 was not recognized. From our findings, it is difficult to conclude that oral lentigo malignas develop malignant melanomas, and thus further studies are needed.     

Folliculotropism in pigmented facial macules: Differential diagnosis with reflectance confocal microscopy

Pigmented facial macules are common on sun damage skin. The diagnosis of early stage lentigo maligna (LM) and lentigo maligna melanoma (LMM) is challenging. Reflectance confocal microscopy (RCM) has been proven to increase diagnostic accuracy of facial lesions. A total of 154 pigmented facial macules, retrospectively collected, were evaluated for the presence of already‐described RCM features and new parameters depicting aspects of the follicle. Melanocytic nests, roundish pagetoid cells, follicular infiltration, bulgings from the follicles and many bright dendrites and infiltration of the hair follicle (ie, folliculotropism) were found to be indicative of LM/LMM compared to non‐melanocytic skin neoplasms (NMSNs), with an overall sensitivity of 96% and specificity of 83%. Concerning NMSNs, solar lentigo and lichen planus‐like keratosis resulted better distinguishable from LM/LMM because usually lacking malignant features and presenting characteristic diagnostic parameters, such as epidermal cobblestone pattern and polycyclic papillary contours. On the other hand, distinction of pigmented actinic keratosis (PAK) resulted more difficult, and needing evaluation of hair follicle infiltration and bulging structures, due to the frequent observation of few bright dendrites in the epidermis, but predominantly not infiltrating the hair follicle (estimated specificity for PAK 53%). A detailed evaluation of the components of the folliculotropism may help to improve the diagnostic accuracy. The classification of the type, distribution and amount of cells, and the presence of bulging around the follicles seem to represent important tools for the differentiation between PAK and LM/LMM at RCM analysis.     

Utility of teledermatopathology for intraoperative margin assessment of melanoma in situ,lentigo maligna type: A 6 year community practice experience

BackgroundAchieving negative margins for melanoma in situ, lentigo maligna type can be challenging, particularly on cosmetically sensitive areas.ObjectiveTo assess the utility of intraoperative frozen section margin assessment using a teledermatopathology system in the treatment of head and neck lentigo maligna.Methods and materialsOver a 6 year period, 96 patients with lentigo maligna had surgical excisions. The margins were assessed intraoperatively with frozen sections prepared in the manner used in Mohs surgery. The surgeon guided the frozen section slides around the margin while a dermatopathologist assessed the margin remotely.ResultsIn 2/96 (2.1%) cases, the safety margin was positive (frozen sections were false negative). In 1 further case (1%) there was a recurrence of the melanoma 13 months following the excision.ConclusionThe described method is effective in treating melanoma in situ, lentigo maligna type with clearance rates similar to previous studies for Mohs surgery.     

Superficial dermal melanocytosis of the elderly: An exceptional occurrence?

The development of flat pigmented lesions on chronically sun-damaged (CSD) skin of the face may represent the clinical manifestation of a wide variety of hyperplastic/neoplastic melanocytic proliferations. We report the exceptional case of an acquired pigmented patch occurring on CSD skin, histopathologically characterized by diffuse hyperplasia of dendritic/spindled melanocytes in the superficial dermis within a widened band of actinic elastosis. This lesion was associated with a small focus of early invasive lentigo maligna melanoma (LMM). We show the melanocytic nature of the population of dermal pigmented cells by means of single and double immunohistochemical staining for melanocytic and histiocytic markers. The biologic significance of the focus of LMM within the hyperpigmented lesion (whether random collision phenomenon or causally related occurrence), as well as the pathogenesis of the whole dermal lesion are difficult to elucidate. Our case emphasizes the need for a better understanding of the pathophysiology of so-called dermal melanocytes.     

卵巢甲状腺肿MRI和CT表现

目的 分析卵巢甲状腺肿的MRI、CT表现。方法 回顾性分析14例经手术病理证实的单发卵巢甲状腺肿患者的MRI及CT表现,观察其形态、大小、密度/信号、强化特点等。结果 14例病变均表现为包膜完整的囊实性肿块,其中分叶状11例,类圆形3例;多囊状13例,单囊1例;11例实性成分为明显厚壁或分隔,3例呈结节状。肿瘤最大径为3~34 cm,平均（11.34±2.24） cm。7例MR T2WI囊性部分均可见极低信号区,增强后无强化,实性成分明显强化。7例CT囊性部分均可见高密度区,CT值57~90 HU,增强扫描未见强化;实性成分明显强化,CT值为145~270 HU;4例囊壁或实性结节中见斑片状钙化。结论 卵巢甲状腺肿的MRI、CT表现具有一定特征性,有助于诊断及鉴别诊断。     

恶性卵巢甲状腺肿发病机制和诊疗的研究进展

卵巢甲状腺肿是具有高度特异性的单胚层分化的成熟畸胎瘤,其主要由甲状腺组织构成。良性卵巢甲状腺肿的恶变率低,为0.5%~5%。恶性卵巢甲状腺肿(MSO)与起源于甲状腺的恶性肿瘤具有相似的分子发病机制,如BRAF(B-Raf proto-oncogene)、RAS(retrovirus-associated DNA sequence)基因点突变,RET/PTC(RET proto-oncogen/papillary thyroid carcinoma)基因重排等。因MSO临床罕见,目前仍缺乏明确的诊断标准及处理原则。一些肿瘤专家主张用原发性甲状腺癌的病理标准作为MSO的诊断依据。MSO一旦确诊后,应行全面的手术分期和术后的辅助治疗,辅助治疗包括全甲状腺切除或甲状腺素抑制治疗、放射性碘治疗、体外照射等。临床观察发现MSO预后均较好,且术后辅助治疗起重要作用。术后需要长期随访,血清甲状腺球蛋白、131I全身扫描是检测肿瘤转移和复发的特异性指标。     

卵巢甲状腺肿超声诊断与误诊分析

目的 探讨卵巢甲状腺肿(SO)的超声声像学表现特征,以提高超声对SO临床诊断价值。方法 回顾性分析我院2010年1月～2019年10月经手术病理证实7例SO超声声像图资料,并结合病理分析误诊的原因。结果6例表现为多房囊实性混合回声包块,1例为单囊性肿块。囊性部分各房腔回声不均匀,部分囊腔透声比膀胱内液体透声差;实性部分位于各囊腔之间,实性部分呈蜂窝状稍高回声并可探及较丰富血流回声。结论 SO超声表现具有一定特征,如囊性部分透声比膀胱内液体差;实性部分位于各囊腔之间,且呈蜂窝状稍高回声并探及丰富血流回声等,有助于提高诊断准确性。     

Radiotherapy for melanotic freckles

Five patients who received radiotherapy (RT) for 7 melanotic freckles (MF, also known as Hutchinson's freckles, lentigo maligna) were reviewed 8 to 37 months after their treatment by RT. Local control and a favourable cosmetic result occurred in all patients. Treatment toxicity was minimal. Few reports about the use of RT for MF exist. Many other treatments including observation alone have been associated with high rates of recurrence, and in some cases conversion to invasive melanoma has occurred. RT appears to be a safe and effective treatment for this condition, providing that doses equivalent to 44 Gy in 11 fractions or more are given.