Cutaneous Keratocyst With D2-40 Immunoreactivity in Basal Cell Nevus Syndrome

ABSTRACT

Although not a diagnostic criterion for basal cell nevus syndrome (BCNS, OMIM#109400), cutaneous cysts, particularly epidermoid cysts, are common in this condition. Cutaneous keratocysts, on the other hand, are extremely rare in general and have been identified in only 5 patients with BCNS. Here, we describe a BCNS patient with a cutaneous keratocyst that demonstrated D2-40 (podoplanin) immunoreactivity, which has been detected in odontogenic keratocysts but not cutaneous keratocysts. This finding suggests that cutaneous keratocysts may be developmentally homologous to odontogenic keratocysts and may behave similarly in terms of invasion and growth pattern.

Verrucous pilar cysts infected with beta human papillomavirus

Epidermoid cysts with histopathologic features of human papillomavirus (HPV) infection have been previously reported and are commonly termed verrucous cysts. We report a series of eight histopathologically distinct verrucous pilar cysts, distinguished from traditional verrucous epidermoid cysts by trichilemmal keratinization, as well as two verrucous hybrid pilar-epidermoid cysts. These lesions contain characteristic stratified epithelial linings with abrupt transitions to compact eosinophilic keratin, as well as areas of papillomatosis, coarse intracytoplasmic keratohyalin granules, and vacuolar structures suggestive of HPV-induced cytopathic change. HPV-24, a β genus HPV species, was identified by degenerate polymerase chain reaction in DNA extracted from two of the lesions, and the presence of β-HPV E4 protein was confirmed by immunohistochemistry. HPV-60, the HPV species most commonly reported in verrucous epidermoid cysts, was not detected. Verrucous pilar cysts represent histopathologically and potentially etiologically distinct lesions which may be underrecognized.

Cutaneous Epithelial Lesions Induced by N-Methyl-N-nitrosourea in Male Sprague-Dawley Rats: A Possible Animal Model for Human Keratoacanthoma

A single intraperitoneal injection of 50 or 75 mg/kg N-methyl-N-nitrosourea in male Sprague-Dawley rats at 4 weeks of age, dose-dependently resulted in cutaneous epithelial cysts and tumors of pilosebaceous origin. Cysts were composed of epidermal cysts or mixed epidermal and inner root sheath hybrid cysts. The majority of induced tumors were keratoacanthomas. A few tumors were trichofolliculomas, trichoblastomas, pilomatricomas, or sebaceous adenomas. All tumors were benign pilosebaceous tumors. Keratoacanthomas were crater-shaped tumors with thick infoldings of epithelium containing keratohyalin granules (epidermal lip) that abruptly changed to epithelium containing trichohyalin granules. The morphological similarity and resemblance of keratin 1, 10, and 14 profiles, and p63 and β-catenin expression between mixed epidermal and inner root sheath hybrid cysts and keratoacanthomas suggests that hybrid cysts progressed to keratoacanthomas, and the cells from infundibular cells to inner root sheath cells of the pilar segment seem to be the origin of rat keratoacanthomas. Immunohistochemical localization of keratins 1, 10 and 14, p63, and β-catenin in trichofolliculoma, trichoblastoma, and pilomatricoma, as well as keratoacanthoma, may indicate tumor histogenesis.

Histopathological, histogenetic, and immunohistochemical analysis of epidermoid cyst of spleen

Splenic cysts are encountered not uncommonly, but large cysts occupying a significant portion of the spleen are extremely rare. We report a case of a young female patient presenting with a large epidermoid cyst involving the majority of the spleen. The patient was involved in a motor vehicle accident during which she sustained multiple rib fractures and traumatic internal organ injuries. She subsequently underwent exploratory laparotomy and splenectomy for grade III splenic lacerations. Incidentally, a 13.3 cm in greatest dimension splenic cyst replacing the majority of the splenic parenchyma was identified. Grossly, the inner lining of cyst was gray-white, smooth, and glistening. Histologically, the thick fibrous cyst wall was composed of stratified squamous epithelium, scattered foci of which were denuded. A panel of properly-controlled immunohistochemical stains was performed and showed the squamous epithelium to be strongly and diffusely immunoreactive with carcinoembryonic antigen (CEA), CA 19-9, and cytokeratin 5/6, focally immunoreactive with HBME-1, and negative for calretinin. The histomorphological features and immunohistochemical staining pattern were consistent with a diagnosis of an epidermoid cyst of the spleen.

Squamous cell carcinoma originated from an epidermal cyst

Epidermal cyst (EC) of the skin is a very common condition. Squamous cell carcinoma (SCC) very infrequently arises from EC. A 76-year-old Japanese woman was admitted to our hospital because of multiple papules in the nose and nasal cavity. The clinical diagnosis was sebaceous hyperplasia. An excisional biopsy was obtained from one papule. Histologically, the papule showed an EC. The EC communicated with the epidermis. Islands of atypical cells with hyperchromatic nuclei and infrequent pearl formation were recognized around and adjacent to EC. No connections were seen between the atypical cell islands and epidermis. The atypical cells had hyperchromatic nuclei and nucleoli. Mitotic figures and keratinous pearls were scattered. The HE diagnosis was probable SCC probably arising from EC. Immunohistochemically, the atypical cells were positive for pancytokeratin AE1/3, cytokeratin (CK) 5/6, CK14, CK18, CK 34BE14, EMA, p53, Ki-67 (labeling 90%), and p63. They were negative for pancytokeratin CAM5.2, CK7, CK8, CK19, CK20, vimentin, S100 protein, HMB45, synaptophysin, and CD56. CD68 was positive in histiocytes and giant cells in the foreign body reaction. The EC showed the same immunoprofile as the SCC, except for negative p53 and low Ki-67 labeling in the EC. The histological and immunohistochemical diagnosis was definite SCC arising from EC.

Seborrheic inclusion cyst of the skin positive for cytoplasmic inclusion bodies and HPV antigen

Seborrheic inclusion cyst (SIC) is a very rare variant of epidermal cyst of the skin. SIC shows seborrheic keratosis (SK)-like lesion in epidermal cyst. SIC is extremely rare; only 6 case reports have been published in the English literature. However, no immunohistochemical study of SIC has been reported. A 41-year-old Japanese man noticed a subcutaneous tumor in the neck. Physical examination showed slightly mobile tumor in the subcutaneous tissue, and total excision was performed. Grossly, the tumor (1 x 1 x 0.8 cm) was cyst containing atheromatous keratin. Microscopically, the lesion is a cyst containing keratins. About one half of the cyst showed features of epidermal cyst consisting of mature squamous epithelium with granular layers. The other one half showed SK-like epidermal proliferation. The SK-like area showed basaloid cell proliferation with pseudohorn cysts. No significant atypia was noted. Many eosinophilic cytoplasmic inclusion bodies were noted in the SK-like area. Immunohistochemically, the SK-like area was positive for pancytokeratin AE1/3, pancytokeratin CAM5.2, p63, and Ki-67 (labeling=8%) and HPV, but negative for p53. The pathological diagnosis was SIC.

Extensive sublingual epidermoid cyst--diagnosis by immunohistological analysis and proof by podoplanin

AIM

We present the case of a surgically treated 39-year-old man with diagnosis of a giant sublingual internal epidermoid cyst. Usually, such dermoid or epidermoid cysts are caused by aberrant ectodermal tissues or by acquired aberrant epithelial tissues arising from the foetal period, or from trauma or surgery. The incidence of oral dermoid or epidermoid cysts is about 1.6%; most occur at the mouth floor but they nevertheless are very rare.

CASE REPORT

The patient presented with a history of progressive swelling of the sublingual region with dysphagia, progressive snoring during sleep and occasional shortness of breath. The suspected clinical diagnosis of a giant sublingual dermoid or epidermoid cyst was supported by the radiological finding after performing magnetic resonance imaging. The cyst was surgically removed under general anaesthesia through an intraoral approach. The immunohistological analysis of the specimen with a monoclonal antibody against podoplanin (D2-40) showed a positive reaction in the basal epithelial layer, exclusively in areas with secondary inflammation, but not in the remaining cyst wall.

CONCLUSION

Sublingually situated extensive epidermoid cysts are rare findings in the oral cavity. In such cases, surgical excision remains the only treatment. We demonstrated that cystic epithelia were normally not immunoreactive for D2-40 but strong immunoreactivity was observed in the basal epithelial cell layer, in areas of ruptured cyst wall associated with secondary inflammatory changes.

Epidermoid cyst occurring within an intrapancreatic accessory spleen. A case report and review of the literature

CONTEXT

Epidermoid cysts occurring within intrapancreatic accessory spleens are exceptionally rare entities, with only 21 previously reported cases. Their clinical presentation prior to pathologic assessment can raise concern for possible malignancy; however, they behave in a benign fashion.

CASE REPORT

A 62-year-old male presented with complaints of abdominal pain. Imaging revealed left-sided retroperitoneal mass and surgical exploration was recommended. Surgery revealed a cystic cavity containing necrotic debris originating from the tail of the pancreas. Microscopy was consistent with an epidermoid cyst arising within an intrapancreatic accessory spleen with positive immunoperoxidase staining for CEA.

CONCLUSION

Epidermoid cysts occurring within intrapancreatic accessory spleens can mimic a malignant process both clinically and radiographically. Surgery with pathologic assessment is the only reliable means of diagnosis. While they are a very rare entity, it is an important component of a complete differential diagnosis for a patient presenting with a pancreatic tail mass.

[Immunohistochemical study of calretinin in normal hair follicles and tumors with follicular differentiation]

BACKGROUND

Selective immunostaining for calretinin labels the innermost layer of the outer root sheath of normal hair follicles, which is difficult to distinguish with hematoxylin-eosin staining.

OBJECTIVE

The aim of this study was to determine whether immunohistochemistry for calretinin allows identification of cutaneous adnexal tumors with follicular differentiation towards cells of the outer root sheath.

MATERIAL AND METHODS

We analyzed the staining pattern for calretinin by immunohistochemistry in 49 biopsies of cutaneous adnexal tumors with follicular differentiation.

RESULTS

Fifteen biopsies corresponded to trichilemmomas/inverted follicular keratosis and had staining for calretinin in the epithelium of the most superficial areas of the lesions and in squamous eddies. Ten were trichilemmal cysts, which displayed staining of the cyst wall. Three were basal cell carcinomas with variable staining according to the type of follicular differentiation in each variant. One was a panfolliculoma that had focal staining. Two were folliculosebaceous cystic hamartomas with staining of the excretory duct of the sebaceous glands. Two pilomatricomas and 3 proliferative trichilemmal tumors had positive staining in the cellular layers close to the lumen of the cystic structures. Nine trichoblastomas/trichoepitheliomas, 2 infundibular cysts, 1 dilated pore of Winer, and 2 acanthomas of the follicular sheath were negative for calretinin.

CONCLUSION

Immunohistochemistry for calretinin allows identification of cutaneous adnexal tumors of the hair follicle or a component of the follicle with differentiation towards cells of the outer root sheath.

Epidermoid splenic cyst presented as huge splenic abscess: a case report

Epidermoid splenic cysts are very rare. Symptoms emerge because of enlargement, infection, haemorrhage or rupture. Although splenectomy is indicated for large cysts, minimally invasive and preservation procedures, such as partial splenectomy or total cystectomy with splenorrhaphy, have been increasingly used during the last decade. We report herein the case of a 16-year old female presented with left upper abdominal quadrant pain, fever and abdominal distention treated in our department.

Proliferating trichilemmal cyst of the eyelid

PURPOSE

To report a case of proliferating trichilemmal cyst in a 55-year-old woman.

DESIGN

Observational case report.

METHODS

A 55-year-old woman sought treatment for a mass in the right upper eyelid. The lesion was excised twice previously, and recurred. The mass was reexcised and examined histopathologically.

RESULTS

Light microscopy showed a cystic lesion lined by stratified squamous epithelium with a compact layer of eosinophilic keratin without granular cell layer. There was no atypia, mitosis, or stromal invasion.

CONCLUSIONS

Although proliferating trichilemmal cyst shows benign histopathologic features, clinical manifestations may mimic those of more aggressive tumors with local recurrences or distant metastasis. Wide excision of the lesion and close long-term follow-up is recommended.

[Diffuse muscular calcification with subcutaneous cysts]

OBJECTIVE

Diffuse muscular calcification was rare myopathological change due to abnormal metabolism of calcium, which was mainly found in dermatomyositis and myositis ossificans progressiva. Here we reported a case of diffuse muscular calcification that clinically mimicked myositis ossificans progressiva. The disease might be a new type of congenital calcium metabolic disease.

METHODS

A 15-year-old girl developed subcutaneous cysts in the wrist and ankle when she was 1 year old. At the age of 9, she developed recurrent fever with myalgia, fatigue and diffuse muscular calcification. It was difficult for her to squat, run or walk. Protuberance presented in the subcutaneous tissue of her trunk. Some nodules ruptured with outflow of chalky material. ESR, ENA, RF, CRP, PTH, CK were in normal limits. EMG was unremarkable. X-ray confirmed diffuse calcification in the muscle and subcutaneous tissues. Biceps muscle biopsy was performed.

RESULTS

Numerous inflammatory cells infiltrated around vessels in the perimyosium with perifascicular muscle fiber atrophy and degeneration. Many RRF and SDH positive fibers were also observed. EM showed tubular reticular inclusions in vascular endothelium.

CONCLUSION

Diffuse muscular calcification indicated existence of systemic calcium metabolic abnormality. As the clinical symptoms and distribution pattern of calcification were different from dermatomyositis with subcutaneous calcification and myositis ossificans progressiva, our case might be a new type of disease. The microvascular changes might result in the lesion of muscle fibers.

A pseudoepidermoid cyst arising from exuberant squamous metaplasia of the gallbladder

Squamous lesions of the gallbladder are uncommon. We report a case of a pseudoepidermoid cyst in a middle-aged woman arising on a background of chronic cholecystitis and cholelithiasis, which induced exuberant squamous metaplasia of the entire gallbladder mucosa, clinically mimicking a gallbladder tumor. To our knowledge, this is the first such reported case in the English literature.

Apocrine Gland Cyst with Hemosiderotic Dermatofibroma-Like Stroma

Two cases of an unusual cutaneous lesion characterized by a dermal nodule with apocrine gland cysts surrounded by a hemosiderotic dermatofibroma-like proliferating stroma are reported. The first case was a 52-year-old female who presented with a nodule on the back of several years of evolution and with the clinical diagnosis of lipoma; the second case was a 41-year-old male who presented with a forehead nodule of several years of evolution with a clinical diagnosis of epidermal cyst. Histologically, an ill-delimited non-encapsulated nodule composed of cystic spaces and solid areas was found. The cystic spaces consisted of ductal structures and a bilayered epithelial covering with apocrine differentiation; the surrounding area showed a stroma composed of a mixture of both fibrocytes and macrophages and abundant hemosiderin granules; foci of recent hemorrhages and a more dense fibrous stroma at the periphery with typical storiform areas were also visible. Both cases have shown a benign course without local recurrence in follow up until this report date.

Nucleolar organizer regions (NORs) in simple and proliferating trichilemmal cysts (pilar cysts and pilar tumors)

Simple trichilemmal cysts or pilar cysts and pilar tumors are relatively rare entities often under-reported by pathologists. The pilar cysts are thought to proliferate and progress to pilar tumors. These pilar tumors can further undergo malignant change. We analyzed 25 pilar cysts and eight pilar tumors, including three with atypia and one malignant pilar tumor, with a view to study the above progression and assess the degree of cell proliferation using the Nucleolar Organizer Regions (AgNORs). There was a progressive increase in the AgNOR count from one dot per nucleus in pilar cysts to 1.5-2 in benign pilar tumors. AgNORs in pilar tumors with atypia (2.8) was more than the benign pilar tumors but were definitely less than the malignant pilar tumors (3.5). The malignant pilar tumor showed bizarre AgNORs and cells with as many as eight to nine AgNORs. Thus AgNOR counts suggested that there is a progressive increase in the degree of cell proliferation and thereby the AgNOR staining from pilar cysts to pilar tumors. This AgNOR staining could also be used to assess the cell proliferation in case of pilar tumors with atypia where it is difficult to rule out malignancy.

A case of epidermal cyst with pilomatrical differentiation

A 20-year-old Japanese woman with an epidermal cyst on the back is described. Physical examination revealed a deep blue and round shaped cystic lesion measuring 10 min in diameter. A comedo-like keratotic plug also could be seen at the center. Histologically, the inner surface of the cyst was clearly separated of two types of the cells. The one was layers of epidermal keratinocytes and the other looked like a basal layer of epidermis, which immunohistochemically stained by S-100, HMB-45, cytokeratin (CK19) and Fontana-Masson staining. We diagnosed this case as epidermal cyst with pilomatrical differentiation.

Expression of parathyroid hormone (PTH)-related peptide (PthrP) and PTH/PTHrP receptor in osteoclast-like giant cells

Osteoclast-like giant cells (OCGC), which resemble osteoclasts at both the morphologic and immunohistochemical levels, develop in neoplastic tissue. In bone marrow, parathyroid hormone (PTH)-related peptide (PTHrP) can induce osteoclast differentiation by stimulating osteoclast progenitors through the PTH/PTHrP receptor (PPR). To evaluate the possible involvement of PTHrP in OCGC formation in tumors, we analyzed both PTHrP and PPR expression by immunohistochemistry in giant cell tumor of bone (GCTB) and anaplastic thyroid cancer (ATC) containing OCGC. In all cases of either GCTB (n = 5) or ATC (n = 4), intense stainingfor PTHrP was found in OCGC, but only faintly in mononuclear cells. PPR expression in OCGC was also demonstrated in 3 cases of GCTB and 2 cases of ATC. Double staining for PPR and proliferating cell nuclear antigen (PCNA) revealed that PPR was mainly expressed by PCNA-negative mononuclear cells and OCGC in these tumors. This suggests that OCGC might be derived from non-proliferating mononuclear cells by PTHrP stimulation via PPR. Furthermore, the profiles of PTHrP and PPR expression in OCGC were compared with those in the neoplastic GC found in malignancy (n = 6), osteoclasts in bone with osteoarthritis (n = 5), reactive GC, including Langhans-type and foreign body-type in pulmonary tuberculosis (n = 8), and ruptured epidermal cyst (n = 14) in order to clarify whether their distribution pattern was unique to OCGC. In all cases of malignancy, expression of both PTHrP and PPR was observed ubiquitously in neoplastic GC and mononuclear cells regardless of PCNA immunoreactivity. In contrast, in osteoclasts and reactive GC, PTHrP immunoreactivity was seen in all cases and in 7 of 22 cases, respectively, but no PPR expression was observed in either. In situ hybridization confirmed PTHrP expression at the transcriptional level in OCGC and neoplastic GC, but not in osteoclasts. Thus, although PTHrP expression was commonly observed in various types of multinucleated giant cells, their immunohistochemical profiles for PPR were distinct. We conclude that PPR might play a role during OCGC formation in GCTB and ATC.

Phospholipase Cdelta1 is required for skin stem cell lineage commitment

Phosphoinositide-specific phospholipase C (PLC) is a key enzyme in phosphoinositide turnover and is involved in a variety of physiological functions. Here we report that PLCdelta(1)-deficient mice undergo progressive hair loss in the first postnatal hair cycle. Epidermal hyperplasia was observed, and many hairs in the skin of PLCdelta(1)-deficient mice failed to penetrate the epidermis and became zigzagged owing to occlusion of the hair canal. Two major downstream signals of PLC, calcium elevation and protein kinase C activation, were impaired in the keratinocytes and skin of PLCdelta(1)-deficient mice. In addition, many cysts that had remarkable similarities to interfollicular epidermis, as well as hyperplasia of sebaceous glands, were observed. Furthermore, PLCdelta(1)-deficient mice developed spontaneous skin tumors that had characteristics of both interfollicular epidermis and sebaceous glands. From these results, we conclude that PLCdelta(1) is required for skin stem cell lineage commitment.

Differential expression of S100 calcium-binding proteins in epidermoid cysts, branchial cysts, craniopharyngiomas and cholesteatomas

AIMS

To investigate whether epidermoid cysts, branchial cysts, craniopharyngiomas and cholesteatomas express S100 proteins differentially by immunohistochemical assaying the presence of S100A1, S100A2, S100A3, S100A4, S100A5, S100A6 and S100B.

METHODS AND RESULTS

Immunopositivity/negativity was recorded for each S100 protein in a series of 52 cases consisting of 12 epidermoid cysts, 12 branchial cysts, 15 adamantinomatous craniopharyngiomas and 13 acquired cholesteatomas. Except in the case of the craniopharyngiomas, immunoreactivity was assessed independently in the basal membrane and the basal, the internal and the keratin layers. Our data show that in contrast to S100B, which was rarely expressed, S100A1, S100A2, S100A4 and S100A5 were often present in these four types of epithelial lesions. S100A3 and S100A6 and, to a lesser extent, S100A5 were the most differentially expressed proteins across the different histopathological groups analysed. These three proteins are expressed more often in craniopharyngiomas and cholesteatomas, the two more aggressive types of lesions.

CONCLUSIONS

This is the first study to report data on the expression of seven S100 proteins in different histopathological groups of epithelial head and neck lesions, whose precise embryological origins are still a matter of debate. S100 proteins could possibly be used as markers to target this embryonic origin, since our results show that S100A3 and S100A6 (and, to a lesser extent, S100A5) are expressed differentially across these different groups of epithelial lesions.

Carcinoma arising in a proliferating trichilemmal cyst expresses fetal and trichilemmal hair phenotype

Carcinomas that arise in a proliferating trichilemmal cyst (PTC) have been described under a variety of names. Monoclonal antibodies (mAbs) indicating follicular differentiation have become available and were used here in two rare tumors with uncommon biologic behavior. To further elucidate the histogenesis of carcinomas arising in a PTC, mAbs to hair follicle stem cells and to hair follicle differentiation-specific cytokeratins (mAbs to cytokeratin [CK] 7, CK8, CK18, and CK19 as well as mAbs to CD8/CK15 and CD34) were studied on paraffin-embedded sections of two cases of carcinoma arising in a PTC, one anaplastic carcinoma, and one poorly differentiated squamous cell carcinoma (SCC). For comparison, concurrent PTCs and trichilemmal cysts as well as four SCCs from controls were studied. The anaplastic carcinoma showed expression of CK7, indicating a fetal hair root phenotype, and expression of CD34, indicating trichilemmal differentiation. In contrast, the poorly differentiated SCCs as well as the control SCCs stained negative for most of the mAbs applied. Expression of fetal and trichilemmal hair follicle phenotypes suggests differentiation from hair stem cells and might explain differences in biologic behavior.

Accumulation of intraventricular fat in an intracranial epidermoid tumor: case report

OBJECTIVE AND IMPORTANCE

A fat component within the ventricles or subarachnoid space in fat-containing tumors such as an epidermoid or a dermoid has been observed in rare instances. However, there have been no reports regarding an increase in the size of such a fat component. We describe the case of an epidermoid tumor with intraventricular fat that showed an increase in size and amount.

CLINICAL PRESENTATION

A 26-year-old woman was admitted with headache and diplopia. Computed tomography and magnetic resonance imaging of the brain revealed a fat-containing suprasellar tumor and widespread fat globules in adjacent sulci and cisterns and within the frontal horn of the lateral ventricle.

INTERVENTION

The patient underwent a pterional craniotomy. Removal of the suprasellar tumor was nearly total. Histopathological examination revealed an epidermoid tumor. Sequential magnetic resonance imaging throughout the ensuing 65-month period revealed no evidence of tumor recurrence; however, the intraventricular fat remained and increased in size. The patient underwent surgery via the transcallosal approach at 69 months after the initial operation, and the presence of free-floating oily fat globules was confirmed.

CONCLUSION

In the case of a fat-containing tumor with free fat in the cerebrospinal fluid spaces, careful serial examination is necessary, with particular attention to the possibility of changes in size.

Cutaneous ciliated cyst: a case report with immunohistochemical evidence for dynein in ciliated cells

Cutaneous ciliated cysts (CCCs) are rare benign lesions predominantly occurring in the lower limbs of young women. We observed such a lesion in the perineal region of a 12-year-old girl. The histogenetic interpretation of CCCs is controversial. The similarity of the epithelial lining of the cyst to the salpingeal epithelium supports the hypothesis of a Müllerian heterotopia. Strong dynein positivity observed immunohistochemically in the apical portion of CCC lining cells suggests the integrity of the ciliary apparatus. There was a marked similarity between a CCC and normal salpingeal epithelium in the mode of staining for dynein, whereas the dynein reactivity of bronchial epithelial cells showed larger cytoplasmic aggregates of positive material in proximity to the nucleus. No immunohistochemical staining for estrogen or progesterone receptors was identified in our observation, although this finding could have supported the Müllerian histogenetic hypothesis. To the best of our knowledge, this is the first time that antidynein immunohistochemistry has been applied to paraffin-embedded samples from human surgical pathology.

Fine-needle aspiration cytology findings in 214 cases of nonparotid lesions of the head

The use and limitations of fine-needle aspiration (FNA) of lesions of the parotid gland are known, but those of nonparotid lesions of the head have been described only sporadically. We conducted this study to evaluate the utility of FNA and to analyze the causes of diagnostic discrepancies for these lesions. A total of 6,898 FNAs of different sites was performed at our institutions between January 1991-August 1998, and 214 (3.1%) of the cases were FNAs of nonparotid lesions of the head. The most common diagnosis of nonparotid lesions was squamous-cell carcinoma, in 22% (n = 48), and the most common site aspirated was the scalp, in 34% (n = 73). Lipomas and keratinous cysts comprised 5% (n = 9) of the total. A statistical analysis was conducted on 98 paired cytology and histology (n = 83) and cytology and flow cytometry (n = 15) specimens (70 malignant and 28 benign). FNA recognized the malignant and benign nature of the lesion in 60 and 26 cases, respectively with 86% sensitivity 93% specificity and 88% accuracy. Causes of false-negative FNA diagnoses (n = 10) included sampling error (n = 6), bloody smears with scant cellularity (n = 3), and bland cytomorphology (n = 1). Florid granulation tissue and a mucocele of the tongue accounted for the two false-positive cases. We conclude that FNA is an effective tool for triage of surgery candidates with nonparotid lesions of the head. Adequate samples with sufficient cellularity are required for avoiding false-negative diagnoses. Occasionally, tissue biopsy is needed for diagnosis of equivocal cases.

Immunohistochemical observation of cytokeratins in keratinous cysts including plantar epidermoid cyst

Sixteen cases of epidermal cyst (EC) (6 cases of conventional EC and 10 cases of plantar epidermoid cyst (PEC)) and 9 cases of trichilemmal cyst (TC) were examined by an immunohistochemical technique using various antibodies against cytokeratins and human papilloma virus (HPV) in order to clarify their histogenesis. There was no difference in immunoreactivities between EC and PEC with or without HPV infection. In TC, the inner layers of the cyst wall were stained with the antibody E3 (CK17), and the outermost layer was stained with the antibodies 4.1.18 (CK8) and 170.2.14 (CK19). In PEC and EC, however, the cyst wall didn't react with these antibodies, and differentiation-specific cytokeratins were expressed in the inner layer. These results confirmed that the immunoreactivities of PEC and EC were identical to those of normal epidermis or infundibulum, and that those of TC were similar to the outer root sheath between the lower infundibulum and isthmus. Although PEC has been recently reported to originate from eccrine ducts, there was a significant difference in immunoreactivities between PEC and eccrine ducts. Furthermore, on the basis of the fact that sole skin has no hair follicles, PEC was speculated to originate from epidermal implantation.

Lymphoepithelial cyst and epidermoid cyst of the accessory spleen in the pancreas

We report here two rare cystic lesions, a lymphoepithelial cyst (LEC) and an epidermoid cyst of the accessory spleen (ECAS) occurring in the pancreas. Histologically, the LEC was lined by stratified squamous epithelium and surrounded by a layer of lymphoid tissue with germinal centers. The ECAS showed similar histologic features with scattered lymphoid tissue, but splenic pulp tissue was present in the wall. In both cysts, some small pancreatic islets and ducts were seen in the fibrous tissue surrounding the lymphoid layer or the splenic pulp, respectively. The lining epithelia of the LEC and the ECAS, as well as those of retention cysts of the pancreas and epidermoid cysts of the spleen used for comparison, were similarly positive with AE1/3, CAM5.2, CK7, CK13, and carcinoembryonic antigen. CA19-9 was also detected in the epithelial cells of the LEC, the ECAS, and the retention cyst of the pancreas, but not in those of the splenic epidermoid or branchial cleft cysts used for comparison. These findings indicate that LECs and ECASs might develop from the pancreatic ducts protruding into a lymph node or accessory spleen located in the pancreas, respectively. Some of both cysts might cause elevated levels of serum carcinoembryonic antigen and/or CA19-9 and should be distinguished from malignant cystic tumors.

Interaction of cultured keratinocytes and fibroblasts from human psoriatic and normal skin in immunodeficient mice

Clarification of the pathogenesis of psoriasis requires separate studies of the epidermis, dermis, and inflammatory cells. We previously subcutaneously transplanted a mixture of cultured human keratinocytes and fibroblasts into mice to develop cysts with human skin structures. Using this method, we separately cultured psoriatic and normal keratinocytes and fibroblasts. Four mixtures were prepared: normal keratinocytes and normal fibroblasts (NK/NF); psoriatic keratinocytes and normal fibroblasts (PK/NF); normal keratinocytes and psoriatic fibroblasts (NK/PF); and psoriatic keratinocytes and psoriatic fibroblasts (PK/PF). Each mixture was transplanted into immunodeficient mice to observe formation of cysts and histological changes. The cysts varied in structure depending on the mixture, which suggests that psoriatic keratinocytes and fibroblasts had some abnormalities. Psoriatic fibroblasts may be partially responsible for thickening of the epidermis. Cell differentiation might have been accelerated in psoriatic keratinocytes after transplantation, resulting in the loss of epidermis structures.

Epidermoid cyst of the spleen with CA19-9 or carcinoembryonic antigen productions: report of three cases

True splenic cyst is a relatively rare disease, and the majority of the cases are classified as epidermoid cysts. Three cases of epidermoid cysts in the spleen or accessory spleen were studied using an immunohistochemical technique and staining for mucin. In case 1, serum carcinoembryonic antigen (CEA) and CA19-9, and in cases 2 and 3, serum CA19-9, before surgery were markedly elevated, and these levels decreased postoperatively. This strongly indicates the relationship between the increase of tumor marker levels and the presence of the epidermoid cyst. In addition, stratified squamous epithelium in the resected tissues of cases 1 and 2 was positive for anti-CEA antibody and anti-CA19-9 antibody, and that of case 3 was positive for anti-CA19-9 antibody. This strongly supports CEA or CA19-9 production in the squamous epithelium.

Pigmented epidermal cyst

A 58-year-old Japanese woman with a pigmented epidermal cyst on the upper arch of the right external ear is described. The blue appearance of the cyst was striking and uncommon in Japanese. Histologically, abundant melanin pigment was observed in the keratinous mass of the cavity, and epithelial cells showed epidermoid keratinization. Increased numbers of melanocytes in the basal layer, large globular cells of melanocytic origin in the spinous layer, and hair-germ-like aggregates of basaloid cells and melanocytes were also observed. The blue clinical appearance is probably due to the rich melanin granules in the cyst, keratinous mass, keratinocytes, and hair-germ-like structures.

Expression of keratins (K10 and K17) in steatocystoma multiplex, eruptive vellus hair cysts, and epidermoid and trichilemmal cysts

We compared the patterns of keratin 10 (K10) and keratin 17 (K17) expression in epidermoid cysts, trichilemmal cysts, eruptive vellus hair cysts, and steatocystoma multiplex. Epidermoid cysts expressed K10 and eruptive vellus hair cysts expressed K17, whereas trichilemmal cysts and steatocystoma multiplex showed expression of both K10 and K17. Our findings support the opinion that eruptive vellus hair cysts, which stained negative for K10, and steatocystoma multiplex are distinct entities and not variants of one disorder.

Immunohistochemical localization of estrogen receptors in the submandibular gland tumors of female rats

The localization of estrogen receptors (EsR) in the tumor tissues of submandibular glands was examined in female rats, using the indirect immunoperoxidase method in combination with the in situ hybridization technique. Tumors were experimentally produced by 9,10-dimethyl-1,2-benzanthracene (DMBA), and the tumor tissues were fixed with formalin or paraformaldehyde and then embedded in paraffin. In the DMBA-induced submandibular gland tumors, immunoreactivity to EsR-peroxidase conjugate was found in nuclei of the tumor cells which occupied the peripheral rim of the tumor cell nests. In contrast, the reactivity in the normal submandibular glands without tumor was mostly confined to nuclei of the duct cells. When EsR mRNA expression was analyzed in the tumor tissue by in situ hybridization with a cDNA probe, its distribution was identical with that of immunoreactivity to EsR. These data suggest that the ductal cells of the submandibular gland are responsive to ovarial steroids, and that estrogens may play an important role in the maintenance of growth of the submandibular gland tumors.

Epidermoid cyst of the spleen: a cytokeratin profile with comparison to other squamous epithelia

The stratified squamous epithelium of a splenic epidermoid cyst was studied with a battery of monoclonal antibodies to cytokeratin (CK) proteins. CKs 10 and 11 were found in the suprabasal layers of the stratified squamous epithelium, while staining for CK 13 was focal or diffuse throughout. CKs 18 and 19 decorated individual squamous cells or stained the entire thickness of the epithelium. These results were compared with those previously obtained by us in stratified squamous epithelia of ovarian mature cystic teratoma, fetal epidermis, adult epidermis and squamous metaplasia in a peritoneal cyst. From these comparisons it emerges that the epidermoid splenic cyst is either of teratomatous derivation or originates from inclusion of fetal squamous epithelium. Squamous metaplasia of mesothelium or inclusions of mature squamous epithelium appears to be an unlikely source of origin of these cysts.

Immunohistochemical detection of carbohydrate determinant 19-9 (CA 19-9) in intracranial epidermoid and dermoid cysts

We evaluated carbohydrate antigen (CA) 19-9 levels of intracranial dermoid and epidermoid cyst in serum and intratumoral tissue. The preoperative serum levels were mildly to moderately higher than their normal ranges in four of seven patients. In four patients with high serum CA 19-9 levels, they returned to normal ranges in three who had the cyst resected totally and remained slightly high in one with residual cyst. Immunohistochemical studies using anti-CA 19-9 antibody demonstrated positively stained capsule and keratinous tissue. Serum CA 19-9 levels of intracranial dermoid or epidermoid cysts with more teratomatous components may be elevated above normal levels.

The biology of beta-adrenergic receptors: analysis in human epidermoid carcinoma A431 cells

1. G-protein-linked transmembrane signaling has emerged as a major pathway for information transduction across the cell membrane. 2. In addition to photopigments that propagate the signal from light, cell-surface receptors for hormones, neurotransmitters, and autacoids propagate signals from ligand binding to membrane-bound effector units via G-proteins. 3. Biochemical and molecular features of one prominent member of these receptors, the beta-adrenergic receptor, will be highlighted in the present article. 4. The role of the human epidermoid carcinoma A431 cells as a model for the study of the structure and biology of beta-adrenergic receptors will be emphasized. 5. A model for receptor regulation, gleaned from recent advances in the biochemistry, cell and molecular biology of beta-adrenergic receptors, is discussed.

An investigation of cytokeratin expression in skin epithelial cysts and some uncommon types of cystic tumours using chain-specific antibodies

The differentiation state of skin epithelial cysts and some uncommon types of epithelial skin tumours was investigated by immunohistochemical staining, mainly using cytokeratin (CK) polypeptide-specific monoclonal antibodies. Samples of interfollicular epidermis, hair follicles and eccrine sweat glands were included as reference tissues. The CK reactivity in epidermoid cysts and milia is not restricted to CKs involved in epidermal-type differentiation, i.e. CK1, 5, 10 and 14, but in addition CK16, a hyperproliferative keratinocyte marker is suprabasally expressed. CK1 and 10 are other prominent suprabasal markers, while CK14 seems to be preferentially expressed in the basal cell layer. Of the non-epidermal CKs, only CK4 was focally or more extensively detected in about 50% of the cases. In terms of CK reactivity, keratinization of trichilemmal cysts corresponds to the keratinization of the anagen-phase hair follicle in the isthmus. The CK reactivity is again restricted to CK1, 5, 10, 14 and 16. However, the CK1 as well as CK10 reactivity is subject to serious limitations, since both CKs were only convincingly observed in foci of terminal differentiation. Eccrine hydrocystoma obligatorily expresses a complex CK set, including CK7, 8, 14, 18 and 19. This CK set perfectly corresponds to the CK composition observed in acini of eccrine sweat glands. In addition, a discontinuous CK4 and 16 reactivity was seen in about 50% of the sites, while CK1 and 10 displayed a strictly focal appearance. On the other hand, syringoma produces in its distinct structures, a CK pattern reminiscent of the one observed in eccrine sweat gland ducts and includes CK1, 5, 10, 14, 16 and 19.(ABSTRACT TRUNCATED AT 250 WORDS)

Leukocyte chemotactic properties of soluble horny contents in epidermal cysts

Epidermal cysts are one of the most common tumors of the skin. Although asymptomatic ordinarily, they may sometimes become severely inflamed with massive invasion of polymorphonuclear leukocytes (PMN). We studied in vitro PMN chemotactic properties of the aqueous extract prepared from the horny material of epidermal cysts obtained from three patients. A crude aqueous extract of the horny content of the cysts showed PMN chemotactic activity, which, however, was less than that of a horny layer extract prepared from normal skin. Characterization of PMN chemotactic activity using a Sephadex G-75 column showed a peak in the low molecular weight fractions eluting between the vitamin B12 and phenol red markers, which corresponds with the peak of absorbance at 280 nm. The chemotactic substances withstood boiling and trypsin or protease digestion. Although the chemotactic activity was partially ether-extractable, the presence of leukotriene B4 was not demonstrated by radioimmunoassay. In addition to their own chemotactic activity, the horny extracts of epidermal cysts showed cytotaxigenic properties in the presence of fresh serum.

Paget's disease in an epidermal cyst

A case of Paget's disease involving both the epidermis of the nipple and an adjacent epidermal cyst is reported. Immunohistochemistry showed similarity between the infiltrating cells in both sites and those of the underlying mammary adenocarcinoma. Epidermal cysts may be involved in a variety of disease processes which affect the epidermis in general and, unless they are subjected to careful histopathological examination, these diseases may be overlooked.

Fine needle aspiration cytology of primary epidermoid cyst of the brain

The cytologic features of a primary epidermoid cyst of the brain diagnosed by intraoperative fine needle aspiration cytology are reported. The cytomorphologic findings included numerous anucleated squames, polarizable cholesterol crystals and a few squamous cells with keratohyaline granules. This case demonstrated the efficacy of using both the Diff-Quik and Papanicolaou stains in evaluation of cystic lesions of the brain. A discussion of the expected aspiration cytologic findings of other cystic cerebral lesions is also presented.