Dual-wavelength pump-probe microscopy analysis of melanin composition

Pump-probe microscopy is an emerging technique that provides detailed chemical information of absorbers with sub-micrometer spatial resolution. Recent work has shown that the pump-probe signals from melanin in human skin cancers correlate well with clinical concern, but it has been difficult to infer the molecular origins of these differences. Here we develop a mathematical framework to describe the pump-probe dynamics of melanin in human pigmented tissue samples, which treats the ensemble of individual chromophores that make up melanin as Gaussian absorbers with bandwidth related via Frenkel excitons. Thus, observed signals result from an interplay between the spectral bandwidths of the individual underlying chromophores and spectral proximity of the pump and probe wavelengths. The model is tested using a dual-wavelength pump-probe approach and a novel signal processing method based on gnomonic projections. Results show signals can be described by a single linear transition path with different rates of progress for different individual pump-probe wavelength pairs. Moreover, the combined dual-wavelength data shows a nonlinear transition that supports our mathematical framework and the excitonic model to describe the optical properties of melanin. The novel gnomonic projection analysis can also be an attractive generic tool for analyzing mixing paths in biomolecular and analytical chemistry.

[Utility of skin ultrasound in the differential diagnosis of blue lesions, hydrocysts]

Many skin diseases may present as blue papules and nodules; the differential diagnosis includes such different entities such as metastatic melanoma, angioma, lipoma, epidermoid cyst, pilomatrixoma, blue nevus, glomus tumor, or hidrocystoma. Cutaneous ultrasound can be a complementary diagnostic technique of great value in these cases.

Blue nevus of the prostate: incidental finding in radical prostatectomy specimen with a pre-operative echographic image of peripheral hypoechogenic nodule

Blue nevus is a stromal melanin deposition, which is microscopically characterized by deeply pigmented melanin-filled spindle cells within the fibromuscular stroma. Cases with prominent melanosis such as those with grossly visible pigment are uncommon. Melanocytic lesions of the prostate are incidental findings with no evidence of malignant transformation. There have only been very few reports of a malignant melanoma of primary prostatic origin. We report an incidental finding of a blue nevus of the prostate, in a radical prostatectomy specimen, in a 64-years-old man with a pre-operative ecographic image of peripheral hypoechogenic nodule. The are very few reports of blue nevi associated to prostatic adenocarcinoma, but none has been evidentiated before surgery as a distinct ultrasound lesion interpreted as adenocarcinoma, therefore inducing the clinician to perform biopsies and consequently a radical prostatectomy.

Infiltrating giant cellular blue naevus

INTRODUCTION

Cellular blue naevi (CBN) measure 1-2 cm in diameter and affect the dermis, occasionally extending into the subcutaneous fat. The case of a 14-year-old boy with a giant CBN (GCBN) involving the right half of the face, the jugal mucosa and the lower eyelid with a tumour that had infiltrated the bone and the maxillary and ethmoidal sinuses is reported.

METHODS

Biopsies were taken from the skin, jugal mucosa and maxillary sinus. The following markers were used in the immunohistochemical evaluation: CD34, CD56, HMB-45, anti-S100, A-103, Melan A and MIB-1.

RESULTS

The biopsy specimens showed a biphasic pattern affecting the lower dermis, subcutaneous fat, skeletal muscle, bone, jugal mucosa and maxillary sinus, but there was no histological evidence of malignancy. The tumour cells were CD34-, CD56-, HMB45+, anti-S100+ and A-103+. Melan A was focally expressed. No positive MIB-1 cells were identified.

DISCUSSION

The present case shows that GCBN may infiltrate deeply, with no evidence of malignancy.

Primary Orbital Melanoma Associated With a Blue Nevus

A 43-year-old white woman presented with a sudden pain and protrusion of the right eye, along with decreased vision. Orbital CT revealed a well-demarcated lesion in the right intraconal space. After surgical excision, the histopathologic examination revealed a malignant melanoma with a predominant epithelioid cell type, probably arising in a blue nevus. The patient was treated with exenteration followed by radiotherapy.

Blue rubber bleb nevus syndrome: endobronchial involvement presenting as chronic cough

This case report describes a rare presentation of chronic cough secondary to endobronchial involvement with blue rubber bleb nevus syndrome (BRBNS) lesions. BRNBS is a rare syndrome characterized with cavernous hemangiomas involving the skin and GI tract. We report the case of a 37-year-old woman, with known BRBNS, who acquired an intractable cough with a radiograph revealing multiple pulmonary nodules. A bronchoscopy demonstrated various bluish, raised, and hypervascular lesions characteristic for BRBNS involving the right mainstem bronchus and segmental bronchi. To our knowledge, this is the first report of endobronchial involvement with BRBNS.

Developmental venous anomalies and sinus pericranii in the blue rubber-bleb nevus syndrome. Case report

Blue rubber-bleb nevus syndrome (BRBNS) is a developmental disorder that originally was identified by the presence of distinctive cutaneous and gastrointestinal hemangiomas. More recently it has been recognized that the number of affected organs is larger and that BRBNS includes central nervous system vascular malformations. A 52-year-old woman in whom intracranial vascular malformations had been diagnosed earlier presented for evaluation. At birth, several blue nevi had been noted on her tongue, lips, and neck. Cerebral angiography demonstrated an extensive network of developmental venous anomalies and a left anterior sinus pericranii. The literature on BRBNS and developmental venous anomalies is reviewed.

The use of selective lymphadenectomy in malignant blue naevus of the scalp

Malignant blue naevus (MBN) is a rare cutaneous tumour with a close biological resemblance to malignant melanoma. MBN spreads to regional lymph nodes, creating a dilemma in managing patients with clinically negative nodal basins. Sentinel lymph node (SLN) biopsy has evolved as a powerful staging tool by identifying occult metastatic nodal disease in patients with cutaneous malignancies. Here, we report a patient with MBN of the occipital scalp who underwent wide local excision together with preoperative lymphoscintigraphy and intraoperative radiolymphoscintigraphy and vital dye injection to identify all draining SLNs. No occult nodal disease was identified. This report adds to the growing body of literature supporting the role of SLN biopsy in staging individuals with cutaneous malignancies, including MBN.

Endosonography in the diagnosis of "blue rubber bleb nevus syndrome": an uncommon cause of gastrointestinal tract bleeding

Blue rubber bleb nevus syndrome is a rare condition characterized by the presence of multiple angiomatic lesions of the skin. These are associated with similar lesions in other organs, namely in the gastrointestinal tract, causing anemia through chronic bleeding. We describe the case of a 72-year-old woman with microcytic anemia. A barium study revealed irregular lacunae in the distal esophagus. A subsequent endoscopy showed blue nodular lesions similar to angiomas of the esophagus and stomach fundus. Endosonography confirmed its angiomatic nature. Exploration of other organs, using magnetic resonance and cranial computed tomography, did not reveal the presence of this type of lesion. In physical examination, two angiomatic lesions were observed on the face and lips, respectively. These were blue in color and compressible, leaving an empty wrinkled sac that rapidly refilled, typical of angiomas.

Metastatic malignant blue nevus: a case report

This report presents a 63-year-old Caucasian woman with a malignant blue nevus, which is an extremely rare form of melanoma originating from or associated with a preexisting blue nevus. The background blue nevus on the left upper arm, which had been present for 5 to 6 years, increased in size and darkened in color for 3 months prior to histological diagnosis of malignant blue nevus. Although the tumor looked much like a nodular melanoma clinically, the diagnosis of malignant blue nevus was established histologically. The patient had a poor outcome due to metastatic spread of the tumor to the visceral organs 1 year following the initial excision of the tumor. To distinguish this rare tumor from other melanocytic lesions, strict histological criteria are needed to make the diagnosis of malignant blue nevus. Differential diagnosis includes cellular blue nevus, atypical cellular blue nevus, primary malignant melanoma, and metastatic melanoma to the dermis. Malignant blue nevus is most commonly seen on the scalp. The tumor has an aggressive behavior and metastasizes in the majority of patients. This paper describes the second reported case of malignant blue nevus involving the upper arm. Clinical and histological features of this uncommon tumor are presented, along with a review of the literature.

Malignant blue naevus with distant subcutaneous metastasis

Malignant blue naevus is a distinct but rarely documented variant of malignant melanoma, and we describe the triple recurrence of a suprapatellar cellular blue naevus over 12 years in a middle-aged woman. Staging investigations revealed a distant subcutaneous metastasis of the right thigh. Immunohistochemistry of the primary lesion and all recurrences showed S-100, HMB-45, NKI/C-3 and Ki-67 positive cells. However, non-malignant cellular blue naevi from five consecutive other patients were all Ki-67 negative. The change from negative to positive Ki-67 responsivity may therefore be a valuable marker of malignant and metastatic potential in early cellular blue naevi.