Rearrangement and overexpression of the BCL-1/PRAD-1 gene in intermediate lymphocytic lymphomas and in t(11q13)-bearing leukemias

The t(11;14)(q13;q32) translocation and its molecular counterpart, BCL- 1 rearrangement, are consistent features of intermediate lymphocytic lymphoma (ILL). Rearrangement is thought to deregulate the nearby PRAD- 1/BCL-1 proto-oncogene that is a newly identified member of the cyclin family. To characterize further the association between rearrangement of chromosome 11q13 and over-expression of BCL-1. Southern blot analysis was performed in 33 cases of ILL, 5 cases of t(11;14)- associated leukemias, and 1 case of leukemia carrying a variant translocation t(11;19)(q13;q13) using three separate BCL-1 locus probes. When RNA was available, BCL-1 expression was assessed by Northern blot analysis. DNA from 19 of 33 ILL (57%) showed BCL-1 rearrangement, 16 involving the major translocation cluster (MTC) region and 3 involving a new breakpoint cluster located in the 5' flanking region of the BCL-1 gene. DNA from 3 of 6 t(11q13)-associated leukemias demonstrated a rearrangement involving the MTC. Northern blot analysis showed that BCL-1 was overexpressed in 14 of 15 ILL and in all leukemias analyzed (included the t(11;19) leukemia) relative to normal and malignant lymphoid tissues. These results constitute additional elements in favor of the role of BCL-1 in lymphoid neoplasia and allow us to speculate about its mechanisms of activation.     

Hepatitis C virus infection in the elderly

We studied hepatitis C virus (HCV)-related disease in older people because the treatment rationale for younger asymptomatic patients is based on the long-term prognosis of infection. Of the HCV-antibody-positive patients seen at Freeman Hospital 1990-1994, 25 were >65 years old; 24 were Caucasian and one was Afro-Caribbean. Median age at presentation was 67 years, and five were female. Nine were asymptomatic at presentation, six presented with varices, five with malaise, three with abdominal pain one with pruritis and one with oedema. Risk factors identified were: transfusion (7), haemodialysis (1), health care worker (dentist) (1), and tattoos (2). There was no recognized risk factor for infection in 14, but five of these had done military service in areas of high HCV prevalance. Liver biopsy in 20 showed chronic hepatitis in two, cirrhosis in 12, and cirrhosis and hepatocellular carcinoma in six. Three additional patients also developed hepatocellular carcinoma. HCV genotyping was done in 19 and all were type 1 (1a, 4; 1b, 14; 1 untypable, 1). Eleven died, at median age 71 years (range 65-94 years), five of HCV liver-related deaths and two from HCV-associated non hepatic disorders (non-Hodgkin's lymphoma and fibrosing alveolitis).      

Increased intraepidermal melanocyte frequency and size in dysplastic melanocytic nevi and cutaneous melanoma. A comparative quantitative study of dysplastic melanocytic nevi, superficial spreading melanoma, nevocellular nevi, and solar lentigines

Dysplastic melanocytic nevi (DMN) are distinguished histologically by a hyperplasia of variably atypical intraepidermal melanocytes in a lentiginous epidermal pattern. In order to further characterize the intraepidermal melanocytes of DMN, 4 representative specimens each of DMN, acquired nevocellular nevi (NCN), solar lentigines (SL), and superficial spreading melanoma (SSM) were selected on the basis of predetermined criteria, confirmed in a blind histologic assessment, and compared in a quantitative morphologic study using 6 micron-thick hematoxylin and eosin stained sections of L-dihydroxyphenylalanine (dopa) preincubated vertical tissue slices of lesion and adjacent normal skin. The average melanocyte frequency, expressed as the percent of dopa-reactive perikarya among 600 consecutive basal unit cells, was significantly greater in DMN (60 +/- 23%) than in NCN (18 +/- 3%), SL (25 +/- 7%), and adjacent skin (14 +/- 3%), but similar to that in SSM (71 +/- 11%). The average mean diameter of 200 consecutive epidermal basal unit melanocytes was significantly larger in DMN (11 +/- 2 microns) than in NCN (7 +/- 0.4 microns), SL (6 +/- 0.1 microns), and adjacent skin (6 +/- 0.4 microns), but significantly smaller than in SSM (16 +/- 3 microns). The observed similarities of intraepidermal melanocytes in selected DMN and SSM, as well as distinct differences from melanocytes in selected NCN and SL, support the hypothesis that some varieties of DMN may represent potential precursors of cutaneous melanoma.     

Unusual and unknown aspect of cutaneous malignant melanoma: minimal deviation malignant melanoma. Retrospective study of 45 cases

Minimal deviation malignant melanoma (MDMM) is a rare melanocytic tumor of the skin that shares both malignant and benign histologic features: 1) a vertical growth phase similar to that of malignant melanomas with expansile nodules invading throughout the reticular dermis (Clark's level IV), and even the subcutaneous fat (Clark's level V); 2) but a monotonous and uniform proliferation of melanocytic cells that are only moderately atypical. A very slight cellular maturation from the top to bottom of the lesions may be observed, but usually there is no maturation at all. By themselves, the cells do not appear as malignant. A borderline variant of MDMM shows identical cytological and growth pattern features, but remains confined to a Clark's level III of invasion. Over the past 14 years, 45 cases (female to male ratio: 1.5:1.0) of MDMM, 8 of which were of the borderline variant, were observed. The lesions appeared as acquired pigmented tumors, 0.5 to 1.0 cm in size which predominated on the trunk. Young adults (mean age: 34 years) were most frequently involved. Based on the cytological characteristics of the cellular proliferation, they could be subdivided in 4 groups: 1) epithelioid and spindle cell type (15 cases); 2) epithelioid type (14 cases); 3) spindle cell type (7 cases); and 4) pigmented spindle cell type (9 cases). The mean thickness of the 45 cases was 3.06 mm (1.24 mm for the borderline lesions; 3.40 mm for the MDMM). Tumors with a spindle cell component appeared thicker than those without. Mitoses were numerous (mean: 3.2/10 high power fields). Each tumor but one showed a junctional component. This appeared as melanocytic hyperplasia or melanocytic nests at the dermoepidermal interface. Moreover, 10 cases (7 MDMM and 3 borderline tumors) disclosed intraepidermal spread of melanocytes. However, as observed with the dermal component of the lesions, these intraepidermal melanocytes never appeared cytologically malignant, although moderate atypism could be observed. At last, an association with a compound or dermal nevus was seen in 8 cases. MDMM appears as a particular subgroup of cutaneous malignant melanomas with distinct and characteristic histologic features. Its differential diagnosis includes blue nevus, especially the cellular variant, combined nevus, spindle and epithelioid cell nevus (Spitz-Allen's nevus) and cutaneous metastasis of malignant melanoma. The most important features for the differential diagnosis are the growth pattern, the absence of cellular maturation, the absence of real malignant cells and moderate cellular atypism.(ABSTRACT TRUNCATED AT 400 WORDS)     

Congenital melanocytic nevi: clinical and histopathologic features, risk of melanoma, and clinical management

Congenital melanocytic nevi occur in approximately 1% of newborns and are usually classified according to their size. Giant congenital melanocytic nevi are most simply defined as melanocytic nevi that are greater than 20 cm in largest dimension; whereas small congenital nevi are defined as melanocytic nevi less that 1.5 cm in largest dimension. Congenital nevi can exhibit distinctive histologic features that can help in differentiating them from common acquired nevi. Giant congenital melanocytic nevi are associated with an increased risk of the development of melanoma. On the other hand, there is evidence of an increased melanoma risk in patients with small congenital nevi. Nevertheless, the risk of malignant transformation in small congenital nevi and the lifetime melanoma risk in patients with small congenital nevi remain controversial. In large part due to inconsistency in the reported literature describing patients with congenital melanocytic nevi, the risk of melanoma in these patients remains unclear and consistent guidelines for clinical management do not exist. We review the literature and comment on the course of management for these patients at the Massachusetts General Hospital Pigmented Lesion Clinic.     

In vivo examination of lentigo maligna and malignant melanoma in situ, lentigo maligna type by near-infrared reflectance confocal microscopy: comparison of in vivo confocal images with histologic sections.

In vivo confocal microscopy can noninvasively image thin en face sections within living intact human tissue with high resolution and contrast. This evolving technique may provide clinicians with tools to help detect lentigo maligna lesion progression in vivo and may be important in defining tumor margins, thus providing a more definitive surgical eradication of lentigo maligna and malignant melanoma in situ, lentigo maligna type. We present a case of malignant melanoma in situ, lentigo maligna type, and we describe the images seen with confocal microscopy in correlation with routine histopathology.     

石斛类叶鞘的显微鉴定研究

商品石斛的植物来源复杂,规格繁多,外形鉴定较困难。为了准确鉴定石斛的品种,对常作为药用的16种石斛属(Dendrobium Sw)植物的叶鞘进行了显微观察,发现其表皮细胞的形状,大小,所含草酸钙结晶的形状、大小、分布等种间区别较明显,可作为鉴别石斛种类的科学依据之一。本文对金钗石斛D.nobile Lindl。等16种石斛的叶鞘表面特征加以描述,并附主要特征图和检索表。