Dysplastic naevi with moderate to severe histological dysplasia: a risk factor for melanoma.

BACKGROUND: The risk of malignant melanoma associated with histologically dysplastic naevi (HDN) has not been defined. While clinically atypical naevi appear to confer an independent risk of melanoma, no study has evaluated the extent to which HDN are predictive of melanoma. OBJECTIVES: To estimate the risk of melanoma associated with HDN. Secondarily, the risk associated with number of naevi and large naevi is estimated. METHODS: We enrolled 80 patients with newly diagnosed melanoma along with 80 spousal controls. After obtaining information on melanoma risk factors and performing a complete cutaneous examination, the most clinically atypical naevus was biopsied in both cases and controls. Histological dysplasia was then assessed independently by 13 dermatopathologists (0, no dysplasia; 1, mild dysplasia; 2, moderate dysplasia; 3, severe dysplasia). The dermatopathologists were blinded as to whether the naevi were from melanoma subjects or controls. Multivariate analyses were performed to determine if there was an independent association between the degree of histological dysplasia in naevi and a personal history of melanoma. RESULTS: In persons with naevi receiving an average score of > 1 (i.e. naevi considered to have greater than mild histological dysplasia), there was an increased risk of melanoma [odds ratio (OR) 2.60, 95% confidence interval (CI) 0.99-6.86] which persisted after adjustment for confounders (OR 3.99, 95% CI 1.02-15.71). Very few dermatopathologists reliably graded naevi of subjects with melanoma as being more dysplastic than naevi of control subjects. Among the entire group, the interobserver reliability associated with grading histological dysplasia in naevi was poor (weighted kappa 0.28). CONCLUSIONS: HDN do appear to confer an independent risk of melanoma. However, this result may add more to our biological understanding of melanoma risk than to clinical assessment of risk, because HDN assessed by a single pathologist generally cannot be used to assess risk of melanoma. Future studies should be directed at establishing reproducible, predictive criteria for grading naevi.

Primary chondroid melanoma.

BACKGROUND: Malignant melanoma is notorious for the wide range of histologic patterns it can assume, among the least frequent of which is chondroid melamona. METHODS: Two cases of primary chondroid melanoma of the distal lower extremity were studied. Tissue for light microscopy was fixed in formalin, embedded in paraffin, and processed routinely. In one case, transmission electron microscopy and immunohistochemical evaluation were performed. RESULTS: Both cases exhibited melanoma in-situ, a conventional (non-chondroid) invasive component, and areas of chondroid differentiation, as confirmed by strongly positive staining with Alcian blue at pH 2.5 and Safranin O. Immunohistochemically, one case expressed S-100 protein and vimentin, and did not express gp100 (HMB-45), tyrosinase, MART-1, the Mel-5 antigen, the NKI/C3 antigen, CD45Ro, cytokeratin, or desmin. Electron microscopy of the chondroid component revealed occasional tumor cells with rare, membrane-bound, electron-dense organelles; the extracellular compartment showed amorphous ground substance consistent with cartilaginous differentiation. CONCLUSIONS: Chondroid change in the absence of osteogenic differentiation is extremely rare in malignant melanoma. Melanoma should be considered in the differential diagnosis of primary cutaneous neoplasms exhibiting cartilaginous differentiation.

Nuchal-type fibroma in two related patients with Gardner's syndrome.

Nuchal-type fibroma is a distinct subcutaneous and dermal fibrous tissue proliferation that has been previously definitely identified in one patient with Gardner's syndrome and has been possibly present in two others. Gardner's syndrome is an autosomal-dominant condition with variable expressivity that comprises epidermoid cysts, fibrous tumors, osteomas, intestinal polyposis, as well as other findings. We report two cases of nuchal-type fibroma presenting in a 13-year-old boy in the right upper back and in his 60-year-old grandfather in the upper chest at the posterior axillary line. Both individuals carried a diagnosis of Gardner's syndrome and neither of them had diabetes. Although the boy has as of now only presented with cutaneous manifestations of Gardner's syndrome, his grandfather has exhibited both cutaneous and intestinal evidence of this syndrome. In addition, the boy's mother and her sister have documented Gardner's syndrome. Light microscopic findings of nuchal-type fibroma from both patients include paucicellular, haphazardly arranged collagen bundles with entrapped adipose tissue. A marked diminution of elastic fibers was noted with Van-Gieson stains. The lesions were diffusely positive for CD34 and contained a few factor XIIIa-positive cells. Electron microscopic analysis revealed no differences between the collagen comprising the nuchal-type fibroma as compared with control dermal collagen obtained from skin away from the tumor. These cases strengthen the view that there is an association between nuchal-type fibroma and Gardner's syndrome.

Keratotic melanocytic nevus: a clinicopathologic and immunohistochemical study.

BACKGROUND: Epidermal hyperplasia in melanocytic nevi is a common but little-investigated phenomenon. METHODS: We prospectively examined all melanocytic nevi diagnosed in our department over an 8-month period, for the criteria of keratotic melanocytic nevus (KMN), namely the presence of marked epidermal hyperplasia with or without horn pseudocyst formation, hyperkeratosis, and papillomatosis. In addition to routine histologic review, we studied 12 representative cases with immunohistochemistry to examine expression of Ki-67, epidermal growth factor receptor (EGFR), Bcl-2, and Bax. RESULTS: From a total of 1,527 melanocytic nevi, 95 were KMN (prevalence 6%). The average age was 34 years, with a male:female ratio of 1:2. The predominant location was the trunk (76%), followed by head and neck (20%), and extremities (4%). Clinical diagnoses were atypical nevus (44%), nevus not otherwise specified (43%), and others including seborrheic keratosis, acrochordon, and basal cell carcinoma. Two KMN were junctional, 44 compound, and 49 intradermal. Twenty-three KMN (24%) had histologic features suggesting congenital onset, and 15 (16%) had mild to moderate dysplastic features. Two cases demonstrated induction of sebaceous glands. Significantly increased Ki-67 expression was detected in the hyperplastic epidermis, particularly in deeper areas related to keratinous cysts and hair follicles. Bcl-2 and Bax (anti- and pro-apoptosis proteins, respectively) and EGFR were expressed similarly in both normal and hyperplastic epidermis overlying the KMN. CONCLUSIONS: KMN are commonly biopsied skin lesions, mostly located on the trunk. Many such lesions are clinically considered atypical, in contrast to their benign histologic appearance. The epidermal hyperplasia on top of KMN demonstrates increased cellular proliferation, in the context of adequately regulated apoptosis and EGFR expression. The cellular proliferation seems to commence in hair follicles.

A comparison of cell cycle markers in well-differentiated lobular and ductal carcinomas.

Infiltrating lobular carcinoma (ILC) and infiltrating ductal carcinoma (IDC) are similar in many respects and their histologic features occasionally overlap. Despite the many similarities, some clinical follow-up data and the patterns of metastasis suggest that ILC and IDC are biologically distinct. Unfortunately, most breast cancer research has focused almost exclusively on the ductal subtype or has not stressed the biologic or molecular genetic distinctions between breast carcinoma subtypes. Several reports have suggested the possibility that ILCs and IDCs differ with respect to expression of antigens involved in proliferation and cell cycle regulation. Therefore, we undertook an immunohistochemical evaluation of cell cycle related antigens in ILCs, including histologic variants thought to represent aggressive neoplasms, and IDCs matched for histologic grade (Modified Bloom-Richardson Grade I). We believe that different antigen expression profiles could elucidate the biological distinctiveness of breast carcinoma subtypes and possibly provide diagnostically relevant information. We studied the expression of the following antigens in 28 archived, formalin-fixed ILCs and 34 well-differentiated IDCs: estrogen receptor (ER), progesterone receptor (PR), Her 2-neu, mib-1, cyclin D1, p27, p53, mdm-2 and bcl-2. 94% of ILCs and 100% of IDCs expressed ER; 75% of ILCs and 76% of IDCs expressed PR; 4% of ILCs and 13% of IDCs expressed c cerb B-2; ILCs and IDCs both expressed mib-1 in approximately 10% of lesional cells; 82% of ILCs and 54% of IDCs expressed cyclin D1; 90% of ILCs and 83% IDCs expressed p27 strongly; 4% of ILCs and 4% of IDCs expressed p53, 25% of ILCs and 33% of IDCs expressed mdm-2; 96% of ILCs and 100% of IDCs expressed bcl-2. None of the apparent differences were statistically significant. The ILC variants demonstrated immunophenotypes that were essentially similar to ILCs of the usual type. We conclude that ILCs and well-differentiated IDCs show similar proliferation and cell cycle control antigen profiles. Despite their unusual histologic features, most ILC variants appear to maintain a characteristic ILC immunophenotype.

Indeterminate fibrohistiocytic lesions of the skin: is there a spectrum between dermatofibroma and dermatofibrosarcoma protuberans?

Routine histology and immunohistochemistry can usually distinguish dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP). DF generally expresses factor XIIIa whereas DFSP generally expresses CD34. The authors report 10 cutaneous fibrohistiocytic lesions combining clinical, histologic, and immunohistochemical features of both DF and DFSP. The lesions had an average size of 1.2 cm (range, 0.4-2.7 cm), and occurred on the trunk (n = 6), extremities (n = 3), and face (n = 1) of four men and six women (average age, 30.6 yrs; age range, 15-50 yrs). Eight lesions exhibited acanthosis and densely cellular fascicles with focal storiform areas. All had keloidal collagen, infiltrated the subcutis in a honeycomb pattern, and had low mitotic counts (0 to 4 mitoses per square millimeter). All were diffusely immunoreactive for factor XIIIa (30%-60% of the neoplastic cells) as well as CD34 (20%-70%). This series raises the possibility of a biologic spectrum between DF and DFSP; however, double-immunolabeling studies showed no notable coexpression of factor XIIIa and CD34 by individual cells, suggesting coexistence of two different cellular populations. After an average follow up of 22.3 months (range, 10-46 mos) in six cases, a single recurrence was documented. The ambiguous histologic features and the potential for local recurrence suggest that performing a complete excision may be prudent in these diagnostically indeterminate lesions.

Expression of CD34 in sclerotic ("plywood") fibromas.

CD34 antigen is expressed in normal human skin on endothelium, in spindle cells located around adnexal structures, and in a subset of interstitial cells in the reticular dermis. CD34 expression has also been identified in a number of fibrohistiocytic neoplasms, such as dermatofibrosarcoma protuberans and solitary fibrous tumors of soft tissue. CD34 expression has not previously been described in sclerotic, or "plywood" fibromas. Here presented are three lesions from three patients, in which histologic examination revealed a well-circumscribed dermal nodule composed of spindled cells with focal nuclear pseudo-inclusions. There was extensive fibrosis with hypocellular, storiform areas, characteristic of sclerotic fibroma. The spindled cells strongly expressed CD34, but not factor XIIIa or markers of melanocytic, neural, or muscular differentiation. A diagnosis of Cowden syndrome was considered in one of the cases. These cases provide evidence that CD34 expression can occur in sclerotic fibromas, either solitary or associated with Cowden syndrome. When diagnosing a sclerotic fibroma, one should comment in the report regarding the possibility of Cowden syndrome.

Desmoplastic (sclerotic) nevus: an underrecognized entity that resembles dermatofibroma and desmoplastic melanoma.

Desmoplastic (sclerotic) nevus, a benign melanocytic neoplasm characterized by predominantly spindle-shaped nevus cells within a fibrotic stroma, can be confused with fibrous lesions and other melanocytic proliferations, including desmoplastic melanoma. We compared the histologic and immunohistochemical features of 16 desmoplastic nevi, nine desmoplastic melanomas, four hypopigmented blue nevi, and six dermatofibromas. The similarities between desmoplastic nevi and dermatofibromas included epidermal hyperplasia (12 of 16), presence of keloidal collagen (15 of 16), hypercellularity (16 of 16), and increased numbers of factor XIIIa-positive dendritic cells (12 of 12). The absence of adnexal induction (0 of 16), the rarity of lesions with multinucleated cells (3 of 16) or epidermal hyperpigmentation (2 of 16), and the presence of S-100 immunoreactivity (16 of 16) and melanocytic proliferation (9 of 16) helped differentiate desmoplastic nevi from dermatofibromas. The similarities between desmoplastic nevi and desmoplastic melanomas included the presence of atypical cells (16 of 16) and HMB-45 expression in the superficial portion of the lesions (11 of 16). The infrequent location on the head or neck (1 of 16), the absence of mitotic figures (0 of 16), a significantly lower number of Ki-67-reactive cells, and a decrease in HMB-45 expression in the deep area of the lesions (8 of 11) helped distinguish desmoplastic nevi from desmoplastic melanoma. Desmoplastic nevi had overlapping features with hypopigmented blue nevi, but features tending to favor the latter included a predominance of ovoid nuclei, higher numbers of atypical cells, and homogeneous staining with HMB-45. We conclude that a combination of histologic and immunohistochemical criteria facilitates the reliable diagnosis of desmoplastic nevus from its simulators.

Quantitation of intraepidermal T-cell subsets in formalin-fixed, paraffin-embedded tissue helps in the diagnosis of mycosis fungoides.

Differentiation between mycosis fungoides (MF) and cutaneous inflammatory processes can usually be made on clinical and histologic grounds. In difficult cases, immunohistochemical studies can be helpful since MF infiltrates usually contain a predominance of CD4+ lymphocytes, while most inflammatory lesions usually have a mixture of CD4+ and CD8+ lymphocytes. However, this determination has traditionally required the use of frozen tissue, thus severely limiting its usefulness. Recently, antibodies that differentially label CD4+ and CD8+ lymphocytes in formalin-fixed, paraffin-embedded tissue have become available (OPD4 and C8/144B respectively, DAKO (Carpinteria, CA, USA). This study tests the utility of these antibodies in the pathologic diagnosis of MF and inflammatory lesions with significant exocytosis. In 9 cases of MF for which both frozen and fixed tissues were available for comparison, the OPD4+ cell count in fixed tissue was significantly lower than the Leu-3a+ cell count in frozen tissue. Also, the C8/144B+ cell count in fixed tissue was higher than the Leu-2a+ cell count in frozen tissue, although this difference was not significant statistically. In a larger series for which only fixed tissue was available, epidermal CD4:CD8 ratios were significantly greater in 23 MF cases (mean 4.0+/-4.76) than in 35 inflammatory cases (mean 0.6+/-0.42; p = 0.001). Thus, although the studied antibodies appear to detect different epitopes in frozen versus paraffin-embedded tissue, demonstration of an elevated CD4:CD8 ratio in fixed tissue supports the diagnosis of MF, and is a helpful adjunct to routine histopathology.

Immunohistochemical analysis of insulin-like growth factor-binding proteins -1, -2, and -3 in implantation sites of the mouse.

PURPOSE: Our purpose was to analyze potential interactions between the embryo and the maternal endometrial interface in vivo by analyzing immunolocalization of insulin-like growth factor-binding proteins (IGFBPs) -1, -2, and -3 in implantation sites of the mouse. METHODS: Six-week-old B6D2F1 female mice underwent superovulation followed by mating and sacrifice at timed intervals. Formalin-fixed paraffin-embedded tissue was used for avidin-biotin immunocytochemical localization of IGFBPs utilizing standard methodology. RESULTS: Immunostaining at 1.5 days post coitum revealed light staining in the epithelial glandular cells and faint staining in decidual stroma for both IGFBP-1 and IGFBP-2. At 7.5-10.5 days post coitum, there was moderate-dense immunostaining in the decidualized stromal cells at the implantation site for all three IGFBPs, whereas light immunostaining was seen in nonimplantation site decidua. CONCLUSIONS: Compartmentalization of immunostaining for IGFBP-1, -2, and -3 within decidualized stroma suggests that these proteins may be regulated by trophoblastic and/or embryonic signals.

Presacral carcinoid tumors: report of three cases and review of the literature.

The clinical, microscopic, immunohistochemical, and ultrastructural features of three carcinoid tumors of the presacral region are reviewed. All tumors occurred in young women and did not involve the rectum. The predominant microscopic pattern was trabecular. The differential diagnosis included paraganglioma and myxopapillary ependymoma. Immunohistochemically, neuroendocrine markers and low molecular weight cytokeratins were expressed in all cases. Neurosecretory granules were identified in the single case studied by electron microscopy. One case was associated with a tailgut cyst (retrorectal cystic hamartoma). Two patients were treated with complete local excision and are free of disease 3 and 4 years after surgery. One case metastasized to both breasts and recurred locally after an incomplete excision. This report expands the already long list of sites where carcinoid tumors can arise. The frequent association of these tumors with tailgut cysts and their histologic similarities to rectal carcinoid tumors suggest that the most likely derivation of presacral carcinoid tumors is from hindgut rests.

Epstein-Barr virus latent gene expression in primary effusion lymphomas containing Kaposi's sarcoma-associated herpesvirus/human herpesvirus-8.

Primary effusion (body cavity-based) lymphoma (PEL) is a recently recognized subtype of malignant lymphoma that exhibits distinctive clinical and biological features, most notably its usual infection with the Kaposi's sarcoma-associated herpesvirus (KSHV). The vast majority of cases also contain Epstein-Barr virus (EBV). This dual viral infection is the first example of a consistent dual herpesviral infection in a human neoplasm and provides a unique model to study viral interactions. We analyzed the pattern of EBV latent gene expression to determine the pathogenic role of this agent in PELs. We examined five PELs coinfected with EBV and KSHV by reverse transcription-polymerase chain reaction (RT-PCR), in situ hybridization, and immunohistochemistry. EBER1 mRNA, a consistent marker of viral latency, was positive in all PEL cases, although at lower levels than in the non-PEL controls due to EBER1 expression by only a variable subset of lymphoma cells. Qp-initiated mRNA, encoding only EBNA1 and characteristic of latencies I and II, was positive in all PEL cases. Wp- and Cp-initiated mRNAs, encoding all EBNAs and characteristic of latency III, were negative in all cases. LMP1 mRNA, expressed in latencies II and III, was present in three cases of PEL, although at very low levels that were not detectable at the protein level by immunohistochemistry. Low levels of LMP2A mRNA were detected in all cases. BZLF1, an early-intermediate lytic phase marker, was weakly positive in four cases, suggesting a productive viral infection in a very small proportion of cells, which was confirmed by ZEBRA antigen expression. Therefore, PELs exhibit a restricted latency pattern, with expression of EBNA1 in all cases, and low LMP1 and LMP2A levels.

Cyclin D1 and retinoblastoma protein expression in Kaposi's sarcoma.

Cyclins are implicated in the induction and control of the cell cycle. Cyclin D1 regulates G1-phase progression by phosphorylation of the retinoblastoma protein (pRb). The Kaposi's sarcoma-associated herpesvirus/human herpesvirus 8 (KSHV) contains and transcribes an open reading frame with sequence similarities to cellular D-type cyclins. The KSHV-cyclin protein is associated with kinase activity capable of phosphorylating pRb in vitro. Here, we study for the first time the endogenous cyclin D1 and Rb protein expression in Kaposi's sarcoma (KS) tissue. Twenty-four consecutive biopsies of AIDS-related (n=21) and classical (n=3) KS were studied by immunohistochemistry with monoclonal antibodies against cyclin D1 and pRb. We detected cyclin D1 in 1 of 13 patch/plaque stage, in 4 of 5 nodular stage and in 3 of 6 visceral KS lesions. By Western blot analysis, this cellular cyclin D1 monoclonal antibody did not cross-react with the purified KSHV-cyclin protein. The pRb was consistently detected in 24 of 24 KS lesions. In summary, early KS lesions rarely have detectable expression of endogenous cyclin D1. Advanced and disseminated KS lesions tend to have overexpression of endogenous cyclin D1. Therefore, cellular cyclin D1 expression appears to correlate with tumor progression in KS. The endogenous cyclin D1 is antigenically distinct from the KSHV-cyclin homolog. The pRb, which may serve as a substrate for KSHV-cyclin, is found in all KS lesions examined.

The concurrence of duodenal epithelioid stromal sarcoma, pulmonary chondromatous hamartoma, and nonfunctioning pancreatic islet cell tumor. A possible analogue of Carney's triad?

A 63-year-old man with non-insulin-dependent diabetes mellitus and peripheral vascular disease presented with acute pulmonary edema and ascites. He died after a brief illness. Coincidence of duodenal epithelioid stromal sarcoma, pulmonary chondromatous hamartoma, and pancreatic islet cell tumor was found at autopsy. This rare concurrence of three uncommon neoplasms may be a pathogenetic variant or an analogue of Carney's triad in an elderly individual. Since all three tumors expressed markers for neural differentiation, the coincidence of tumors with these features may represent a form of neurocristopathy.