Blue nevus: classical types and new related entities. A differential diagnostic review

<p> </p> <div> <div> <div> <div> <p>Blue nevus is an uncommon pigmented lesion of dermal melanocytes. By convention,two well defined histologic variants, designated as “common” and “cellular”, have been recognised. In the last few years, these lesions have attracted much attention due to the recognition of news entities and to its confusion with malignant melanoma. In the prestient review, we point out the more striking features of new related entities (combined nevus, deep penetrating nevus, compound blue nevus) and establish the differential diagnosis with conflictive lesions such as atypical blue nevus, locally aggressive blue nevus, congenital giant melanocytic nevus with nodular growth and melanocytic dermal tumor of unpredictable outcome. We also review the concept of malignant blue nevus and the significance of lymph node metastases. </p> <p>The blue nevus is an uncommon pigmented lesion consisting of dermal melanocytesthat can appear in diverse forms: dendritic, spindle-shaped, oval-shaped, or polyhedral. Although it usually occurs in skin, it has been reported in other locations, such as oral mucosa, sclera, uterine cervix, vagina, prostate, spermatic cord, pulmonary hilus, orbit, conjunctiva, maxillary sinus, breast, and lymph nodes3,8,42,49. Generally, it occurs in adults as a single, acquired, intensely pigmented lesion, although familial and multiple nevi have been reported7,39. By convention, there are two well-defined histologic variants, designated as “common” and “cellular”, but lesions often manifest intermediate features. </p> <p>In the last few years, blue nevus has attracted much attention due to the recognitionof new (clinical and histologic) entities and to its confusion with malignant melanoma. Our aim is to review the most striking features of the new related entities and to establish the differential diagnosis with conflictive lesions. We also review the concept of malignant blue nevus and the significance of lymph nodes metastasis. </p> </div> </div> </div> </div> <p> </p

Glomus tumour of the oropharynx

<p>Haemangiopericytoma and glomus tumours are infrequent neoplasms in otorrhinolaryngology. A case of glomus tumour with haemangiopericytomatous features of the left amygdalar fossa is reported. Its clinical, surgical and histological features are described. This case report supports the unitary concept of smooth muscle tumours of the small vascular wall.</p

Cellular blue nevus with massive regional lymph node metastases

<p>Small, well-differentiated groups of nevus cells have been found occasionally in the marginal sinuses and parenchyma of regional lymph nodes that drain sites of cellular blue nevi.<br> The histologic, immunohistochemical, and karyometric description of a pigmented cutaneous lesion, with the features of cellular blue nevus and located on the leg of a 14-year-old woman, that was accompanied by synchronic presentation of massive inguinal lymph-node metastases.<br> The excised specimens were processed routinely, embedded in paraffin, and sectioned into 4-microm-thick slices. The sections were stained using hematoxylin-eosin and the ABC immunohistochemical method for demonstrating S-100 and HMB-45. Karyometric analysis was performed in a static cytometer using Feulgen-stained sections.<br> The cutaneous lesion had the cytologic and architectural features of cellular blue nevus. The lymph nodes showed massive invasion by pigmented cells and contained extensive necrotic foci. After 3.5 years of clinical follow-up, the patient is free from disease.<br> The absence of malignant features in the cutaneous lesion and the bland nuclear features of the pigmented cells in the regional lymph node metastases suggest that this case could be interpreted as an unusual form of benign cellular blue nevus with metastases. Nonetheless, other possibilities, such as malignant melanoma mimicking a cellular blue nevus or primary malignant melanoma of the lymph nodes with concomitant cutaneous cellular blue nevus, cannot be definitively excluded. A conservative surgical approach with close follow-up was recommended.</p

Nuclear DNA patterns in adrenal cortex proliferative lesions

<p>In cortical adrenal gland tumours there are discrepancies between morphological criteria for malignancy and biological behaviour. This makes it difficult to select the appropriate treatment. We have studied morphometric and DNA densitometric features of 24 adrenal proliferative lesions (hyperplasia, adenoma, and carcinoma) by means of slide cytometry. All variables have been correlated with pathological diagnosis. The samples were selected from paraffin-embedded tissue, and representative lesions were Feulgen stained. Densitometric study showed aneuploid cell lines in every carcinoma, 5 of 8 adenomas, and 5 of 10 hyperplastic lesions. Both DNA nuclear content (mean ploidy of 2.11 c, 2.41 c, and 3.05 c) mean nuclear area (average of 31.26 microns 2, 35.92 microns 2, and 42.39 microns 2) showed progressive increase from hyperplasia to adenoma, and carcinoma. Mean shape factors were lowest in adenomas (1.69) and highest in carcinomas (1.82). Those karyometric variables which showed statistically significant differences (p < 0.05) among diagnostic groups were included in a stepwise three-way discriminant analysis. Only three parameters, shape factor (p = 0.0008), mean ploidy (p = 0.0012), and adrenal weight (p = 0.0055) persisted as independent predictive factors. Using the three variables selected by discriminant analysis on our cases, 100% of the adenomas were correctly classified, 83% of the carcinomas, and 80% of the hyperplasias. Tumour weight and nuclear shape factor differentiated adrenal cortex adenoma from carcinoma, while mean ploidy distinguished adrenal cortical hyperplasia from carcinoma. Nuclear pleomorphism (shape factor) and DNA-ploidy are the most important nuclear features in predicting the biological course of proliferative adrenal cortex lesions, although by themselves they are not bona-fide discriminators.</p