Cystic tricholemmal carcinoma in situ.

An 89-year-old man presented with a clinically cystic 4-mm papule on the left temple. The clinical impression was a benign cyst. Pathologic examination revealed a small, symmetric-appearing, well-circumscribed, dermal-based cystic lesion with markedly atypical-appearing clear to squamoid cells lining the cyst wall, consistent with carcinoma in situ involving the cyst. The cells showed abundant glycogen-containing cytoplasm (confirmed by Periodic acid Schiff stains with and without diastase), consistent with tricholemmal differentiation, and areas of tricholemmal/pilar-type keratinization (without a granular layer), consistent with tricholemmal carcinoma in situ, most likely arising in a tricholemmal/pilar cyst. Ki-67 and p53 immunohistochemical stains were strongly positive (with more than 20% of nuclei staining on Ki-67 and more than 80% on p53) in the cyst-lining cells, further supporting the interpretation of carcinoma in situ. Multiple deeper level sections were examined but did not show any evidence of an associated invasive carcinoma. Tricholemmal (pilar) cysts are common benign adnexal lesions and atypia/dysplasia or carcinoma in situ arising within them is exceedingly rare. Previously, only one case of a tricholemmal cyst with carcinoma in situ has been reported. That case was associated with an atypical fibroxanthoma. We report only the second case of tricholemmal carcinoma in situ, most likely involving a tricholemmal cyst, which was not associated with another tumor or evidence of invasive carcinoma.

KAI-1 protein expression in odontogenic cysts.

The KAI-1 tumor suppressor gene is widely distributed in normal tissues and its down-regulation may be correlated with the invasive phenotype and metastases in several different epithelial tumors. The aim of the present study was an evaluation of KAI-1 expression in radicular cysts (RC), follicular cysts (FC), orthokeratinized keratocysts (OOKC), and parakeratinized keratocysts (POKC). Eighty-five odontogenic cysts, 28 RC, 22 FC, and 35 OKC (16 OOKC, 19 POKC) were selected. All the POKC were negative and only four of 16 of the OOKC were positive for KAI-1. On the contrary, all RC and FC cases were positive and immunoreactivity for KAI-1 was detected throughout all the layers of the cyst epithelium. The lack of KAI-1 expression in POKC could help to explain the differences in the clinical and pathologic behavior of OKC and, according to what has been reported for epithelial tumors, could be related to the increased aggressive behavior and invasiveness of OKC.

Cystic panfolliculoma.

Panfolliculoma is a rare follicular neoplasm with differentiation toward both upper (infundibulum and isthmus) and lower (stem, hair matrix, and bulb) segments of a hair follicle. We present an unusual case of cystic panfolliculoma. A 33-year-old Hispanic woman presented with an 8-month history of a 3.0-cm cystic scalp mass. The lesion was excised, and the histologic sections showed a cystic follicular neoplasm that contained corneocytes in basket-woven and laminated array, trichohyalin granules of the inner root sheath, germinative cells, papillae, matrical cells, and "shadow" cells. Cytokeratin 903 and cytokeratin 5/6 immunostains uniformly highlight the tumor cells. Ber-EP4 strongly labels the germinative cells but not the follicular papillae. CD34 labels the surrounding fibrotic stroma and focally the epithelial component.

Evaluation of estradiol in aspirated ovarian cystic lesions.

During a three-year period, 217 ovarian cystic lesions were evaluated by both fine needle aspiration (FNA) cytology and estradiol (E2) assay at Royal Women's Hospital. One hundred three ovarian lesions were subsequently subjected to histologic examination, and 79 cyst fluids were assayed for progesterone. Of the 151 cystic lesions diagnosed by cytology/histology, 50 were follicular cysts, and 90% had E2 content > 20 nmol/L. The remaining 101 nonfollicular cystic lesions represented a heterogeneous group, but 99% had E2 content < 20 nmol/L. The sensitivity of E2 content > 20 nmol/L for follicular cysts was 90% and the specificity 99%. In contrast, progesterone was elevated in follicular cyst fluid but also in many other types of cysts. Consideration of E2 content in the 66 cysts undiagnosed by histology/cytology revealed 33 follicular cysts. The precise nature of the 33 nonfollicular cystic lesions remains unknown, and further investigations, including surgery, are warranted. It is concluded that E2 assay, unlike progesterone assay, constitutes a useful ancillary diagnostic clue in the evaluation of ovarian cystic lesions in the premenopausal woman.

Epidermal growth factor receptor in odontogenic cysts and tumors.

The expression of epidermal growth factor receptor (EGFR) was investigated in 67 cases of odontogenic cysts and 35 cases of odontogenic tumors using monoclonal antibody to EGFR (Biomarker, Israel) to determine the presence and significance of this transmembrane growth factor receptor. The cystic epithelial cells of odontogenic cystic lesions (keratocyst 60%; primordial cyst 75%; radicular cyst 35%; and follicular cyst 47.4%) were positive to EGFR staining. Cytochemical characterization of EGFR in those cystic epithelium was cell membrane positive type as in the normal epithelium. No expression of EGFR was found in the odontogenic tumors. This diversity of EGFR represents no binding activity of EGF, or loss of EGFR in the tumor cell upon EGFR mediated growth in odontogenic tumors was suggested a different tumor cell growth factor status or microenvironment in cell proliferation mechanism at the cellular level in cysts and tumors of odontogenic origin.

Platelet-activating factor levels in human follicular and amniotic fluids.

Platelet-activating factor (PAF) was estimated in extracts of human follicular and amniotic fluids using a commercially available 125I-radioimmunoassay. Levels obtained before and after purification of the extracts by thin-layer chromatography were similar and PAF could be estimated with high accuracy and reproducibility over a wide dilution range. PAF levels in fluid aspirated from mature (17 mm average diameter) follicles from in vitro fertilization patients were 1005 +/- 129 fmol/ml in successful (clinical pregnancy) cycles and 949 +/- 75 fmol/ml in unsuccessful (failure of implantation) cycles. PAF levels were also similar in follicles containing eggs and those where no egg was found, and in fluid from follicular cysts characterised by low oestradiol and progesterone levels. PAF was detected in midtrimester amniotic fluid (60 +/- 20 fmol/ml). At term, PAF was low or undetectable in amniotic fluid obtained at elective caesarean section before the onset of labour, but increased to 102 +/- 28 fmol/ml in samples obtained following spontaneous labour and vaginal delivery. The data suggest that PAF may be involved in ovulation and parturition but further studies into the mechanism of action of PAF are necessary. The good performance of the radioimmunoassay and the convenience of gamma-counting are strong advantages of this method over the available bioassays, but its expense remains a drawback.