Magnetic resonance imaging in the diagnosis of melanoma: in vivo preliminary studies with dynamic contrast-enhanced subtraction.

The aim of this study was to analyse the potential of fast dynamic subtraction magnetic resonance (MR) imaging in differentiating in vivo melanomas from benign melanocytic lesions. Dynamic MR imaging was performed after intravenous administration of gadopentetate dimeglumine (Gd-DTPA) in 18 patients with melanocytic skin lesions. Using a post-processing algorithm, time-signal intensity curves were obtained for the lesions and classified according to their shapes as type I (steady enhancement increase), type II (plateau of signal intensity) or type III (wash-out of signal intensity). Other parameters evaluated for their potential to differentiate melanomas from benign lesions were the enhancement rate (percentage of signal intensity increase) in the first minute after Gd-DTPA administration, the peak value of the enhancement rate, and the wash-out slope. The pigmented lesions were then surgically excised and the MR results compared with the histological assessment. In melanomas, the mean value of the enhancement rate in the first minute was 611%, whereas in benign lesions it was 131% (P = 0.001). The distribution of curve types was also different: seven of the nine naevi showed type I curves, while eight of the nine melanomas displayed a type III curve. In addition, distinctive wash-out dynamics were observed: the enhancement rate began to decrease between the first and third minutes for melanomas, but continued to increase until the sixth minute for naevi (P = 0.000). These findings, which are most likely related to the neoangiogenesis present in melanomas, indicate that dynamic MR imaging can be helpful in the differential diagnosis of pigmented skin lesions.

Endovascular treatment of pial AVMs: technical options, indications and limits in pediatric age patients.

Our study group consisted of 29 patients who underwent endovascular treatment for the presence of pial AVMs. The patients were treated with various embolization methods including "-free flow" embolization (2 cases); embolization with suture threads (2 mm long micro-emboli: 17 cases) and embolization with acrylic glue (10 cases). There were significant angio-architectural and AVM location differences between the pediatric and the adult patient groups. In pediatric patients, the more frequent AVMs were of the mono or few-pedunculated type, then simple direct fistulas and high-flow fistulous-plexiform AVMs and giant infra-tentorial or deep-seated malformations. In mono or few-pedunculated AVMs, the elected treatment was acrylic glue followed by radio-surgery achieving definitive cure in 3 cases. In direct AVFs and elevated flow AVMs, embolization with suture and acrylic glue offered definitive results. Treatment for infra-tentorial and deep-seated AVMs presented the greatest difficulty in pediatric patients. In two of them, embolization with glue enabled radiosurgery (giant cerebellar AVMs). Our experience did not confirm that current endovascular techniques provide definitive treatment in extensive, deep-seated AVMs. Each treatment, in children more so than in adults, requires a risk/benefit evaluation of the method taking into account the natural history data.

Lymphatic mapping and sentinel node identification in squamous cell carcinoma and melanoma of the head and neck.

AIM: The aim of our study was to evaluate the role of scintigraphy in lymphatic mapping and in the identification of the sentinel lymph node (SLN) in patients with head and neck cancer. METHODS: Between September 1999 and February 2001 we enrolled 22 consecutive patients with cancer in the head and neck region: five squamous cell carcinomas, one Merkel cell tumor of the cheek, and 16 malignant melanomas. Lymphoscintigraphy was performed three hours before surgery after injection of 30-50 MBq of 99mTc -Nanocoll in 0.3 mL; the dose was fractionated by injecting the radiotracer at two points around the lesion. Static acquisition (anterior and/or lateral views, 512 x 512 matrix, 5 mins pre-set time) was started immediately after the injections so as to visualize the pathways of lymphatic drainage. The skin projection of the SLN was marked with ink. Intraoperative SLN detection was performed with perilesional injection of patent blue. RESULTS: SLNs were found with lymphoscintigraphy in all patients. Thirty-three SLNs were identified: one occipital node, three nodes at the base of the tongue, 10 superficial lateral nodes (external jugular), five submandibular nodes, five submental nodes, three mastoid nodes and six supraclavicular nodes. Biopsy was performed in 21/22 patients. In 20/22 patients the first lymph nodes were visualized in the proximal cranial regions (retroauricular, jugular and submandibular) at five minutes post injection. The SLN positivity rate was 13.6% (three patients). All patients with tumor-positive SLNs were submitted to radical dissection. Poor concordance in the detection of sentinel nodes was observed with patent blue. CONCLUSIONS: The flow of nanocolloid in the lymph vessels of the head is rapid. In our experience immediate scintigraphic imaging was essential to visualize the pathways of lymphatic drainage and the first SLN. Radioguided SLN biopsy is therefore recommended within three hours. Injection of patent blue is inadvisable because of the poor concordance with lymphoscintigraphy and the risk of permanent tattooing of the face.

[Sentinel node biopsy for malignant melanoma. Technical details and clinical results on 390 patients]. / La biopsia del linfonodo sentinella nel melanoma maligno. Dettagli tecnici e risultati in 390 pazienti.

BACKGROUND: The purpose of this paper is to present personal experience with sentinel node biopsy for the treatment of malignant melanoma. Technical details influencing the efficacy of the procedure are presented and the clinical, therapeutic and prognostic advantages of this technique discussed. METHODS: A total of 390 consecutive patients with primary skin melanoma (T2-3,N0,M0) underwent sentinel node biopsy between March 1996 and May 2001. All patients underwent previous excisional biopsy of the primary lesion and clinical and radiographic examination to exclude lymphatic or systemic macroscopic spreading of the disease. Preoperative lymphoscintigraphy (99mTc nanocoll) was routinely performed in the last 315 patients. Intraoperative detection of the sentinel nodes was performed by perilesional, intradermical, injection of blue dye associated with a g probe (Neoprobe(R) 2000) in the last 315 patients. Sentinel nodes, serially sectioned, were all Haematoxylin-Eosin and immunohistochemically stained. All patients positive for micro-metastasis underwent radical lymphadenectomy. Comparative analysis between the incidence of metastasis in sentinel and non-sentinel nodes, according to the clinical stage of the disease, was done. RESULTS: The overall detection rate of sentinel nodes was 97.4%. Relevant differences were found according to the site of dissection and the use of a g probe. The g-probe makes the procedure more effective, less invasive and less expensive. Timing and accuracy of the preoperative lymphoscintigraphy is a basic step of the procedure. The overall incidence of positive sentinel nodes was 14.7% with differences correlated with thickness of primary lesion (0.75-1.5 mm: 5,8%; 1.5-3 mm:18%; 3-4 mm: 24.6%). Metastasis in other non-sentinel nodes was found only with primary tumour thickness exceeding 2 mm. CONCLUSIONS: Sentinel node biopsy is a procedure requiring a multidisciplinary approach (surgery, nuclear medicine and pathology). A specific learning phase (>30 patients) is recommended to obtain reliable results.

Papular clear cell hyperplasia of the eccrine duct in a diabetic.

We report a patient with a widespread papular disorder characterized by extensive clear cell hyperplasia of the secretory portion of the eccrine units. A 46-year-old woman had a long history of diffuse papules which gave the skin a 'goose-flesh' appearance. She had severe diabetes. Histological examination of a papule showed marked clear cell hyperplasia that involved the secretory duct of all eccrine units present in the specimen sparing the secretory coil. The clear cells were periodic acid-Schiff (PAS) positive and Alcian blue negative. Ultrastructural study confirmed that the clear cells contained abundant intracytoplasmatic glycogen. We suggest that the diabetic condition may be important in promoting the accumulation of glycogen in the eccrine ducts. Our patient represents a peculiar disorder of the eccrine units that, on the basis of clinicopathological features, we have termed papular clear cell hyperplasia of the eccrine duct.

[Erythema dischromicum perstans (ashy dermatosis). Report of two cases]. / Erithema dischromicum perstans (ashy dermatosis). Presentazione di due casi.

Clinical, histological and ultrastructural investigations of two cases of Erythema Dischromicum Perstans (EDP) are reported. EDP is a chronic pigmented lesion of the skin, and its etiology is still unknown. The reported cases showed clinical and ultrastructural differences from what already described in the literature. EDP is also difficult to differentiate from other cutaneous pigmented lesions: clinical and morphologic differences and/or similarities are therefore discussed and compared. The usefulness for a correct diagnosis of the co-existence of optical and ultrastructural lesions which are not pathognomonic per se, is also stressed.

Infantile condylomata of the oral cavity.

A child had condylomata acuminata localized to the oral cavity. Main points of interest were this exclusive localization, the extremely high number of papillary lesions, not reported in the literature until now, and the excellent response to interferon and local applications of podophyllin. Histologic, ultrastructural, and in situ molecular hybridization techniques were performed to make a correct diagnosis. Transmission of the etiologic agent and therapeutic approaches are discussed.

Correlation between clinical atypia and histologic dysplasia in acquired melanocytic nevi.

BACKGROUND: The validity of clinical and histologic criteria in identifying dysplastic nevi is controversial. Recognition of the dysplastic nevus as a distinct clinicopathologic entity requires demonstration of significant agreement between clinical atypia and histologic dysplasia. OBJECTIVE: We attempted to determine the correlation between clinical atypia and histologic dysplasia in acquired melanocytic nevi and to evaluate the sensitivity and specificity of clinical criteria for dysplastic nevi when compared with histopathologic features. METHODS: A total of 940 acquired melanocytic nevi 3 mm in diameter or larger were selected by initially choosing clinically unequivocal dysplastic and nondysplastic nevi and then, from these, histologically unequivocal dysplastic and nondysplastic lesions. The level of concordance between clinical atypia and histologic dysplasia was estimated by kappa statistics. RESULTS: Nevi were classified as clinically dysplastic (n = 499) or nondysplastic (n = 441). On the basis of histologic features, 739 were classified as dysplastic and 201 as nondysplastic. Agreement between clinical atypia and histologic dysplasia was found in 432 nevi, that is, a sensitivity of 58.4% (3-5 mm = 27.2%, >5 mm = 69.8%). Agreement between clinical and histologic criteria on the absence of dysplasia was found in 134 nevi, a specificity of 66.6% (3-5 mm = 92.4%, >5 mm = 47.9%). The kappa value was 0.17 (3-5 mm = 0.14, >5 mm = 0.10). CONCLUSION: The limited sensitivity and specificity together with the negligible kappa value indicate a poor agreement between clinical and histologic diagnoses of dysplastic nevus. The dysplastic nevus cannot be considered a distinct clinicopathologic entity because histologic dysplasia is found in a range of nevi that may or may not show clinical atypia.