Basaloid Epithelial Cells Research Articles

Hajdu-Cheney Syndrome: Report of a Case

Hajdu-Cheney syndrome is a rare disorder characterized by short stature, joint hypermobility, distinctive craniofacial and skull abnormalities, dental anomalies, and acroosteolysis of the distal phalanges. Cystic kidneys have been associated with some cases. We report a case of a 12-year-old girl with renal failure who underwent bilateral nephrectomies. Histopathological examination revealed polycystic kidneys with numerous nodules located throughout the kidney composed of basaloid epithelial cells.

Clear Cell Trichoblastoma

Clear cell change in basal cell carcinomas is a well-recognized phenomenon, but is obviously rare in trichoblastomas. We present two cases of clear cell trichoblastoma in which clear cell change was very much prominent, and the results of an ultrastructural study intended to explore the basis of that feature. Both our patients were women, aged 56 and 77 years, who presented with solitary, slowly growing nodules that measured 3 to 5 cm in largest dimension and were located on the scalp and the flexor aspect of the lower arm. Microscopically, the tumors in both cases were symmetric, non-ulcerated, and composed of variably sized and shaped (cribriform, racemiform, strands, cords, nodules) aggregations of monomorphous basaloid epithelial cells that were associated with a specific trichogenic stroma. Common to both tumors was clear cell cytoplasm evident in the majority of the epithelial cells in one case and almost in the entire epithelial cell population in the other. In most epithelial aggregations the epithelial cells with clear cytoplasm often appeared columnar and were arranged in a palisade along a recognizable basal membrane, thus indicative of outer sheath differentiation at the bulb. There were other signs of follicular differentiation. Ultrastructurally, variably sized clusters of uniform small basaloid epithelial cells were separated from the stroma by a thin discontinuous basement membrane. In addition to the usual organelles, the cytoplasm contained fairly conspicuous tonofilaments and variably sized vacuoles devoid of a limiting membrane, located between the palisaded nuclei and the outer cell membrane. The majority of vacuoles were empty, although clumps of a finely granular substance were occasionally evident. No distinct lipid droplets or glycogen particles were identified. The basaloid cells were joined by scattered small desmosomes. These findings were consistent with trichilemmal differentiation at the bulb.

Melanocytic Matricoma in a Dog

We report a tumor that developed at the root of the tail in a male, 2-year-old Shih Tzu dog. Histologically, the tumor consisted of basaloid epithelial cells, with shadow cells and neoplastic melanocyte proliferation. Immunohistochemically, epithelial components were positive for keratin/cytokeratin but basaloid cells were negative. Mononuclear or multinuclear melanocytes were positive for vimentin, S-100 protein, and HMB-45. In conclusion, this dog was diagnosed with canine melanocytic matricoma on the basis of the similarity of the histologic and immunohistochemical features in humans, and it may be the first case in an animal.

Ber-EP4 antigen is a marker for a cell population related to the secondary hair germ.

Ber-EP4 is an antibody to a cell membrane glycoprotein of unknown function. In the skin, Ber-EP4 immunoreactivity has been reported to be localized in structures composed of basaloid epithelial cells, i.e. fetal epithelial germ cells, basal cell carcinoma, and trichoepithelioma as well as eccrine or apocrine ducts. In this study, we further characterized the follicular expression of Ber-EP4 immunoreactivity at different stages of the hair cycle of human terminal hair follicles. In addition, to clarify the location of Ber-EP4(+) cells, we compared the Ber-EP4 immunoreactivity with the expression of keratin 15 and keratin 19. Positive staining by Ber-EP4 was found in the lower part of the epithelial strand of late catagen hair follicles, in the secondary hair germ of telogen hair follicles, and in the matrix of early anagen hair follicles but not in any parts of mature anagen hair follicles. In contrast, the follicular expression of keratin 15 detected by using LHK15 antibody was restricted to two distinct parts of anagen hair follicles, i.e. the outer root sheath above the hair bulb and that of the isthmus including the bulge area, and to the outer root sheath of late catagen and telogen hair follicles. The follicular expressions of keratin 19 and that of keratin 15 were apparently superimposed, whereas keratin 15 expression was more extended. The immunoreactivity of LHK15 antibody and antikeratin 19 antibody against the secondary hair germ of telogen follicles was negative or dim. Our results suggest that Ber-EP4 reacts with the secondary hair germ and possibly a cell population related to the secondary hair germ but not with the presumptive stem cell population as revealed immunohistochemically either by the keratin 15 or keratin 19 expression.

Keratinized Squamous Cells in Fine Needle Aspiration of the Brain

To analyze the differential diagnosis when keratinized squamous cells are found in a brain aspirate. Twenty cases of brain aspirates with keratinized squamous cells were retrieved (1982-2001). Diagnoses included craniopharyngioma (CP) (n = 11), metastatic squamous cell carcinoma (SCC) (n = 5), epidermoid cyst (EC) (n = 3) and Rathke cleft cyst (RCC) (n = 1). Aspirates were obtained under stereotactic radiologic (CT) guidance. Smears were stained with Diff-Quik or Papanicolaou stain, and cell block sections were stained with hematoxylin and eosin. Radiologic and histopathologic correlation with subsequent resection specimens was performed in selected cases. CP showed cellular smears with numerous keratinized squamous cells in a background of degenerated cellular and keratinaceous debris. Also noted were clusters of anucleate squamous cells, multinucleated giant cells, histiocytes, calcified debris and characteristic fragments of basaloid epithelial cells. Metastatic SCC showed single cells and tissue fragments of markedly atypical and focally keratinized cells with enlarged, hyperchromatic nuclei; prominent pleomorphism in a background of necrotic cellular debris and acute inflammatory exudate. EC showed numerous isolated keratinized squamous cells often with prominent keratohyaline granules and occasional parakeratotic cells in a relatively clean background. RCC showed single cells and aggregates of benign-appearing squamous cells admixed with numerous anucleate squames and hemosiderin-laden macrophages. Glandular-type epithelium was present only rarely. Squamous cell-containing lesions in the brain present a spectrum of pathologic entities. Although they all display the common morphologic denominator of keratinizing squamous cells, subtle cytomorphologic differences exist in these lesions, permitting an accurate cytopathologic diagnosis. Clinicardiologic features and anatomic location of the tumor in the brain are additionally helpful.

Eccrine Porocarcinoma (Malignant Eccrine Poroma)

The clinicopathologic characteristics of 69 cases of eccrine porocarcinoma (EP) have been studied. Seven cases of purely in situ disease are included. Forty patients were female, 29 male with ages ranging from 29 to 91 years (mean 73 years). The lower extremity represented the single most common site (44%). Other common sites were the trunk (15 cases, 24%) and head (11 cases, 18%). The histologic diagnosis of EP was predicated on the basis of an irregular tumor at least partly formed of characteristic poromatous basaloid epithelial cells displaying ductal differentiation, and significant cytologic atypia. Forty-seven tumors (68%) contained mature well-formed eccrine ducts having an eosinophilic luminal cuticle, with the remaining tumors containing small ill-formed ducts and/or intracytoplasmic lumina. All ducts were discernible via light microscopy and in 49 cases were highlighted with DPAS stain and/or CEA/EMA immunocytochemistry. A variant with a broad pushing tumor margin and marked nuclear pleomorphism showed some resemblance to proliferative bowenoid dysplasia. In 11 cases (18%) the tumors appeared to arise in continuity with a benign preexistent poroma. A variety of histologic patterns were displayed including clear, squamous, and spindle cell differentiation, mucus cell metaplasia, and colonization by melanocytes. Lymphovascular invasion was present in 9 cases (15%). Three cases showed pagetoid extension of malignant cells (epidermotropism) and appeared to be multifocal. Follow-up was available in 54 patients (78%) with 9 (17%) experiencing local recurrence, 10 developing lymph node metastases (19%), and 6 (11%) experiencing distant metastases or death. Mitoses, the presence of lymphovascular invasion, and tumor depth >7 mm were associated with a poorer prognosis. Dividing tumors into those with a "pushing" or "infiltrating" advancing margin was also predictive of outcome with the latter having an increased risk of local recurrence. This report, the largest series of EP to date, suggests that the incidence of aggressive behavior is less than popularly believed. Furthermore, EP can display a wide variety of histologic patterns that may lead to diagnostic error in the unwary. The large number of cases in this series enables a reliable evaluation of prognostic parameters. A more aggressive clinical course may be indicated by more than 14 mitoses per high power field (hazard ratio [HR] for death 17.0, 95% confidence interval [CI] 2.71-107), lymphovascular invasion by tumor (HR 4.41, CI 1.13-17.2), and depth >7 mm (HR 5.49, CI 1.0-30.3). Thus, mitoses, lymphovascular invasion, and tumor depth should be evaluated in these tumors. We also suggest that tumors presenting an "infiltrative" advancing margin are particularly prone to local recurrence and require wide excision with close attention to the surgical margins by the reporting pathologist.

Odontogenic ghost cell tumor: A case report with cytologic findings

Odontogenic ghost cell tumor is a rare, neoplastic form of calcifying odontogenic cyst (Gorlin cyst) whose cytologic features have not been previously reported. We present a case of odontogenic ghost cell tumor diagnosed by fine-needle aspiration biopsy (FNAB). The aspirate was characterized by (1) tissue fragments with basaloid epithelial cells, (2) “ghost” cells, (3) scattered multinucleated giant cells, (4) rare, eosinophilic, densely hyalinized “dentinoid” material in close association with the basaloid cells, and (5) calcific debris. The aspirate was diagnosed as “consistent with odontogenic ghost cell tumor.” The cytologic features of odontogenic ghost cell tumor, as described, closely parallel the major histologic findings in this rare tumor. The differential diagnoses include other odontogenic tumors, squamous cell carcinoma, basaloid cell tumors of the salivary gland, and pilomatrixoma. Diagn. Cytopathol. 1998;18:199–203. © 1998 Wiley-Liss, Inc.

The ‘Mantle Hair of Pinkus’

The 'mantle hair' is a hair follicle which is characterized by a circumferential proliferation of basaloid epithelial cells emanating from the base of its infundibulum. These cells show varying sebaceous differentiation. The mantle hair was first described 100 years ago. Since then, this type of hair follicle with its particular sebaceous gland has been forgotten repeatedly, to be rediscovered anew. Thus, a confusing terminology has evolved, and concepts of its nature are controversial. In this article we present a review of the 100-year history of the mantle hair.

Histopathologic Features and Post-surgical Sequelae of 57 Cutaneous Neoplasms in Ferrets (Mustela putorius furo.)

The study of the signalment, histomorphologic features, and post-surgical clinical progress of 57 cutaneous neoplasms in 55 domestic ferrets (Mustela putorius furo L.) was based on diagnostic pathologic accessions (1987-1992) from 142 ferrets. Mean age of the group was 4.3 years; 31/54 (57%) were female and 23/54 (43%) were male. Thirty-three (58%) of the cutaneous neoplasms were basal cell tumors. The mean age of ferrets with basal cell tumor was 5.2 years, and 23/33 (70%) were female. Histologically, the basal cell tumors were composed of well-differentiated basaloid epithelial cells with various degrees of squamous and sebaceous differentiation, similar to those seen in basal cell neoplasms of dogs. Nine of the 57 (16%) cutaneous neoplasms were mastocytomas. The mean age of ferrets with mastocytoma was 4.1 years; four were male, four were female, and the sex of one was unrecorded. Histologically, the mastocytomas were composed of well-differentiated mast cells with few eosinophils, similar to cutaneous mastocytomas of domestic cats. The mast cells had a small number of metachromatic cytoplasmic granules, and in six of eight neoplasms the granules had an affinity for conjugated avidin-peroxidase. Six of the cutaneous neoplasms (11%) were fibromas. The mean age of ferrets with fibroma was 2.7 years; 5 (83%) were male. Two cutaneous hemangiomas (4%) were in females, which were 4 and 5 years of age. There was one each hemangiosarcoma, cutaneous polyp, anal gland adenocarcinoma, lymphosarcoma of the prepuce and inguinal lymph node, and adenocarcinoma of the prepuce.

Basaloid-squamous carcinoma of the tongue, hypopharynx, and larynx:: Report of 10 cases

Ten cases of an unusual form of carcinoma involving the mucosa and underlying tissue of the tongue, hypopharynx, and larynx are described. All ten of the tumors were evaluated by light microscopy; five were also studied by electron microscopy. The major histopathologic feature is carcinoma with a basaloid pattern in intimate association with squamous cell carcinoma, carcinoma in situ, or focal squamous differentiation. The basaloid tumor consists of small crowded cells with hyperchromatic nuclei, scant cytoplasm, small cystic spaces, and foci of tumor necrosis. Prominent hyalinosis is evident. Ultrastructurally, the basaloid epithelial cells possess rare tonofilaments and varying amounts of desmosomes. The cystic spaces contain either loose stellate granules or replicated basal lamina arranged in parallel stacks or globoid masses. This unique tumor was found to be highly malignant, with histologically proved metastases in 80 per cent of the cases. Most of the patients were treated by radical surgery supplemented with radiation and/or chemotherapy. It is concluded that tumors with these characteristic features constitute a distinct histopathologic entity, not previously described, for which basaloid-squamous carcinoma is an appropriate term.