The utility of cytokeratin 5/6 in the recognition of cutaneous spindle cell squamous cell carcinoma.

BACKGROUND: Cutaneous spindle cell squamous cell carcinoma (SSCC) is a challenging diagnosis since it may be difficult to distinguish from spindle cell melanoma, leiomyosarcoma and atypical fibroxanthoma. Furthermore, it may be difficult to demonstrate epithelial differentiation by a traditional immunohistochemical panel. We performed an expanded immunohistochemical evaluation of ultrastructurally documented SSCC to assess its utility in diagnosing this entity. METHODS: We identified 16 cases of SSCC that were composed predominantly of spindle-shaped cells and with ultrastructural evidence of epithelial differentiation (i.e. at least rudimentary cell junctions). Immunohistochemical analysis using antibodies to a variety of cytokeratins (AE1/3, K903, CK5/6) and S-100 protein was performed. The extent of immunostaining was graded on a scale of 0 to 4+ (0: no staining; 1+: < or =25%; 2+: 26-50%; 3+: 51-75%; 4+: >75%). RESULTS: Of the 16 cases, 6 expressed AE1/3 (38%), 8 expressed K903 (50%) and 11 (69%) expressed CK5/6. Six cases were positive for all three CK markers and two cases were positive for both K903 and CK5/6 but negative for AE1/3. Three cases (19%) stained for CK5/6 without any staining for AE1/3 or K903. Five cases (31%) were negative for all epithelial markers. The extent of CK5/6 staining was either similar to or greater than K903 staining in 7 of 8 cases that stained with both markers. All 16 cases were negative for S-100 protein. CONCLUSIONS: Including CK5/6 in the initial battery of immunostains performed on a cutaneous spindle cell neoplasm can help demonstrate epithelial differentiation in SSCC, even in the absence of AE1/3 or K903 staining. However, some cases of cutaneous SSCC can only be confirmed ultrastructurally, as up to one-third may not show evidence of epithelial differentiation using an expanded immunohistochemical panel.

Immunohistochemical analysis of anaplastic lymphoma kinase expression in deep soft tissue calcifying fibrous pseudotumor: evidence of a late sclerosing stage of inflammatory myofibroblastic tumor?

Calcifying fibrous pseudotumor (CFT) is a rare benign soft tissue lesion composed of dense hyalinized fibrous tissue containing bland spindle-shaped cells admixed with a lymphoplasmacytic infiltrate and foci of dystrophic and often psammomatous calcifications. It has been suggested that CFT represents a late sclerosing stage of inflammatory myofibroblastic tumor (IMT). Recently, clonal cytogenetic abnormalities involving the anaplastic lymphoma kinase (ALK) gene on chromosome 2p have been identified in IMT, particularly those arising in deep soft tissue sites. We evaluated seven cases of deep soft tissue CFT diagnosed at the Cleveland Clinic Foundation and the University of Florida with available paraffin-embedded blocks using a monoclonal antibody to ALK (Dako, Carpenteria, CA) and a modified avidin-biotin complex method. The cohort included six women and one man with a median age at diagnosis of 43 years (range, 26 to 67 years). Sites of CFT included mesentery (3), peritoneum (1), omentum (1), serosa of small bowel (1), and anterior mediastinum (1). Immunohistochemically, only one case showed focal staining for ALK. The remaining six cases were negative, with appropriate positive and negative control staining. In conclusion, unlike IMT, CFT in deep soft tissue locations rarely expresses ALK by immunohistochemistry, suggesting that CFT is a different clinicopathologic entity than IMT, as opposed to representing a "burned out" IMT. Ann Diagn Pathol 5:10-14, 2001.

Giant cell angiofibroma of the inguinal region.

Giant cell angiofibroma is a rare mesenchymal neoplasm most commonly arising in the soft tissues near the orbit. Recently, several cases of extraorbital giant cell angiofibroma have been reported. We report the light microscopic and immunohistochemical features of an additional case of extraorbital giant cell angiofibroma arising in the inguinal region that was clinically mistaken for an inguinal hernia. The patient was a 50-year-old woman who presented with a mobile, nonreducible, left inguinal mass. The tumor was 10.8 cm in greatest diameter, was well circumscribed, and appeared to be encapsulated. Histologically, the tumor was composed of a mixture of cytologically bland spindle-shaped cells and ovoid cells of varying cellularity with deposition in a variably collagenous and myxoid stroma. The tumor had prominent, various-sized blood vessels, often with perivascular hyalinization. In addition, scattered pseudovascular spaces filled with an amorphous eosinophilic material were present and lined by spindle-shaped and ovoid cells similar to those found throughout the neoplasm. Rare multinucleated floret-like giant cells were seen. Immunohistochemically, the tumor cells stained strongly and diffusely for both CD34 and bcl-2 while immunostains for S-100 protein, desmin, smooth muscle actin, and muscle-specific actin were negative. There is no evidence of local recurrence or metastasis 3 months following excision of the mass. This report emphasizes the recognition of this unusual tumor in extraorbital sites. We discuss the overlapping histologic and immunophenotypic features with giant cell fibroblastoma and solitary fibrous tumor and raise the possibility that these tumors could represent a histologic spectrum of CD34-positive dendritic interstitial cell neoplasms.

Hyperplastic-like mucosal change in Crohn's disease: an unusual form of dysplasia?

Patients with Crohn's disease are at increased risk of developing intestinal adenocarcinoma. Dysplasia is both a marker and a precursor of adenocarcinoma in this setting. In a review of our cases of Crohn's-related adenocarcinoma, we noted a peculiar hyperplastic-like mucosal change (HPC) in mucosa both adjacent to and distant from the adenocarcinoma in some cases. However, the significance of this change is unknown. We evaluated 30 cases of Crohn's-related adenocarcinoma and 30 age- and site-matched resection specimens with Crohn's disease without adenocarcinoma to determine the prevalence of this mucosal alteration in these groups. HPC was recognized by a diffuse expanse of flat mucosa with an architecture resembling that seen in colorectal hyperplastic polyps and composed of cells with cytologically bland basal nuclei and apical cytoplasmic mucin distention. The relationship of the HPC to the adenocarcinoma was noted in the Crohn's-related adenocarcinoma cases. An immunohistochemical stain for p53 (antibody DO7) was performed on all cases with HPC in both groups. HPC was identified in 10 of 30 (33%) cases of Crohn's-related adenocarcinoma compared with 3 of 30 (10%) cases in the control group (P = .03). In the 10 cases of Crohn's-related adenocarcinoma with HPC, this alteration was found adjacent to the adenocarcinoma in 3 cases, distant to the adenocarcinoma in 5 cases, and both adjacent to and distal from the adenocarcinoma in 2 cases. In two specimens, HPC was seen immediately adjacent to adenocarcinoma in the absence of adjacent dysplasia. p53 immunoreactivity was noted in HPC in 5 of 10 (50%) Crohn's-related adenocarcinomas. In contrast, p53 immunoreactivity was not seen in HPC in the three control cases with this mucosal alteration. In conclusion, HPC is found significantly more commonly in mucosa both adjacent to and distant from Crohn's-related adenocarcinoma when compared with age- and site-matched controls. In addition, p53 immunoreactivity is more commonly seen in HPC in cases of Crohn's-related adenocarcinoma compared with controls. These data suggest that this mucosal alteration may, in some cases, represent an unusual form of dysplasia in this setting.

A morphologic study of dermatofibrosarcoma protuberans: expansion of a histologic profile.

UNLABELLED: Dermatofibrosarcoma protuberans (DFSP) is a fibrohistiocytic tumor of intermediate malignancy characterized by a distinctive storiform growth pattern and frequent local recurrences. In this study, we retrospectively reviewed 48 cases of DFSP diagnosed at the Cleveland Clinic Foundation between 1970 and 1999 to determine the prevalence of morphologic variations including the presence of giant cell fibroblastoma (GCF)-like areas, multinucleated giant cells, hypercellular zones and fibrosarcomatous change. RESULTS: The cohort consisted of 42 patients (20 males, 22 females) with a median age at diagnosis of 40 years (range: 10-73 years). Forty-one primary tumors and seven recurrences were evaluated from these 42 patients. Tumor sites included the trunk (22 cases), head and neck (8 cases), upper extremities (7 cases) and lower extremities (6 cases). GCF-like areas were identified in seven (14.6%), multinucleated giant cells in ten (20.8%), hypercellular zones in 12 (25%) and fibrosarcomatous change in six (12.5%) cases, respectively. Combinations included giant cells and GCF-like areas (two cases), giant cells and hypercellular zone (two cases), and GCF-like areas and hypercellular zones (one case). Our findings suggest that DFSP has a wider range of morphologic features, including GCF-like areas, multinucleated giant cells, hypercellular zones and fibrosarcomatous change, than has been previously recognized in the literature.

Immunohistochemical analysis of CD30-positive lymphoproliferative disorders for expression of CD95 and CD95L.

Primary cutaneous (PC) CD30-positive large cell lymphoma and lymphomatoid papulosis (LyP) represent the spectrum of PC CD30-positive lymphoproliferative disorders (LPDs) associated with a favorable prognosis. Noncutaneous CD30-positive anaplastic large cell lymphoma (ALCL), although morphologically similar to PC CD30-positive LPDs, seems to be a biologically distinct entity. Cell lines derived from noncutaneous ALCL express CD95 and undergo CD95-induced apoptosis. Little is known about expression or function of CD95/CD95L in cutaneous lesions. We examined a series of PC CD30-positive LPDs and noncutaneous ALCL for expression of CD95/CD95L to investigate possible differences between these histologically similar but biologically distinct entities. Paraffin-embedded, formalin-fixed tissue sections from 25 cases of CD30-positive LPDs (10 noncutaneous ALCL, 15 PC CD30-positive LPDs) were immunostained for CD3, CD20 (L26), CD43 (Leu22), CD30 (BerH2), anaplastic lymphoma kinase (ALK-1), CD95, and CD95L (C-33). One hundred large atypical cells and 100 small lymphocytes were counted to determine the percentage of CD95/ CD95L-positive cells. Statistical analysis using the Mann-Whitney U test was performed. CD95 expression was slightly higher in the large atypical cells of noncutaneous ALCL compared with PC CD30-positive LPDs (median, 100% versus 94%; P = .003) because of the lower expression of CD95 in LyP. CD95L expression was higher in the surrounding small lymphocytes in PC CD30-positive LPDs (median, 3% versus 13%; P = .002). Expression of CD95 in the small lymphocytes and CD95L in the large atypical cells was not significantly different. These results support the biologic distinction between cutaneous and noncutaneous CD30-positive LPDs and may have implications in the differing clinical behavior of these entities. Further study of expression and function of apoptosis-related proteins in these entities is warranted.

The diagnosis of low-grade dysplasia in Barrett's esophagus and its implications for disease progression.

OBJECTIVE: The reported risk of progression from low-grade dysplasia (LGD) to high-grade dysplasia (HGD) or carcinoma (CA) in Barrett's esophagus varies. However, the validity of a diagnosis of LGD may be questioned because of interobserver variability. METHODS: A search of the Cleveland Clinic Foundation surgical pathology files between 1986 and 1997 yielded biopsy specimens from 43 patients with Barrett's esophagus diagnosed and coded as LGD. Patients with concurrent or prior diagnoses of HGD or carcinoma were excluded. The LGD cases were randomized and blindly reviewed by three gastrointestinal (GI) pathologists along with cases originally diagnosed as Barrett's esophagus without dysplasia (ND; n = 28), indefinite for dysplasia (IND; n = 14), or HGD (n = 15). Each pathologist classified every biopsy specimen as ND, IND, LGD, or HGD, and interobserver agreements were determined by kappa statistics (K). Follow-up data were available on 25 patients originally diagnosed with LGD. Progression was defined as a subsequent diagnosis of HGD or CA on esophageal biopsy or resection specimens. RESULTS: Agreement between two GI pathologists for a diagnosis of LGD was fair (K = 0.28) and poor (K = 0.21 and -0.04). Individual GI pathologists agreed with the original diagnosis of LGD in 70%, 56%, and 16% of cases. The 25 patients with follow-up included 21 men and four women (mean age, 67 yr) with a mean follow-up of 26 months (range: 2-84 months). Seven patients (28%) with follow-up developed HGD (five patients) or CA (two patients), 2-43 months (median: 11 months) after a diagnosis of LGD. The individual GI pathologists' diagnosis did not correlate with progression. However, when at least two GI pathologists agreed on LGD, there was a significant association with progression (seven of 17 patients, 41%, p = 0.04). When all three GI pathologists agreed on a diagnosis of LGD, four of five patients progressed (p = 0.012). In contrast, of the eight patients with follow-up and no agreement among GI pathologists for a diagnosis of LGD, none progressed. CONCLUSIONS: A high degree of interobserver variability is seen in the histological diagnosis of Barrett's esophagus-related LGD. Although the number of observations is low, a consensus diagnosis of LGD among GI pathologists suggests an increased risk of progression from LGD to HGD or carcinoma.

Intestinal adenocarcinoma in Crohn's disease: a report of 30 cases with a focus on coexisting dysplasia.

There are relatively few reports that detail the types of intestinal adenocarcinoma complicating Crohn's disease and examine associated epithelial dysplasia. We determined the prevalence, grade, and type of dysplasia found adjacent to and distant from Crohn's-related adenocarcinomas. Thirty cases of resected Crohn's-related adenocarcinoma were reviewed, and histologic type, degree of differentiation, TNM stage, and the presence or absence, grade, and location of dysplasia were recorded. Most of the patients were male (70%). The median ages at diagnosis of Crohn's disease and adenocarcinoma were 34 and 49 years, respectively. The extent of Crohn's disease included ileocolitis in 21 patients, only colonic disease in six, and only small bowel disease in three. In most cases (67%), carcinoma was found incidentally at surgery. All carcinomas arose in areas involved by Crohn's disease. Eight (27%) adenocarcinomas arose in the small bowel, and 22 (73%) arose in the colon, including two in out-of-circuit rectums. Most carcinomas (63%) were poorly differentiated. Dysplasia was found adjacent to the carcinoma in 26 (87%) cases. Of the colorectal carcinomas, 19 (86%) had adjacent dysplasia, and nine (41%) had distant dysplasia. In conclusion, most cases of Crohn's-related intestinal adenocarcinoma have dysplasia in adjacent mucosa, and 41% of those arising in the colorectum have distant dysplasia, supporting a dysplasia-carcinoma sequence in Crohn's disease.

Neuroendocrine neoplasms arising in inflammatory bowel disease: a report of 14 cases.

Inflammatory bowel disease (IBD), particularly ulcerative colitis (UC), is a premalignant condition, because these patients are at increased risk of adenocarcinoma. Neuroendocrine neoplasms (NENs) have rarely been described in this setting. We evaluated 14 cases of NEN arising in a setting of IBD. All of the tumors arose in areas involved by IBD, and all showed immunohistochemical or ultrastructural evidence of neuroendocrine differentiation. The cohort included seven men and seven women (range, 28-71 yr; median, 43 yr). Eight patients had Crohn's disease (CD), and six had UC. Duration of disease ranged from 4 months to 50 years (median, 15 yr), with one of unknown duration. Of the eight patients with CD, five had ileocolitis, one had ileitis, one had colitis, and in one case, the extent of disease was unknown. Of the six patients with UC, four had extensive UC, one had left-sided UC, and the extent of UC was unknown in one case. Reasons for surgery included CD complications (five patients), refractory disease (three patients), dysplasia/carcinoma (five patients), and incontinence (one patient). The NENs were well differentiated in 11 cases and poorly differentiated mixed adenocarcinoma/small cell carcinomas in 3 cases. Tumor sites included the rectum (six cases), appendix (four cases), small bowel (two cases), and sigmoid colon (two cases). High-grade dysplasia was present in adjacent mucosa in four cases, and low-grade dysplasia was present in distant mucosa in two cases. Two patients with poorly differentiated NENs died from the disease at 3 and 11 months after tumor excision. All of the other patients were alive without tumor as of last follow-up. We concluded that NENs rarely arise in a setting of IBD. Most are well-differentiated tumors and are clinically indolent. Dysplasia is found in adjacent mucosa in more than one-third of cases, suggesting that neuroendocrine differentiation might evolve from multipotential cells in dysplastic epithelium.