Recurring phyllodes tumor in aberrant breast tissue of the vulva.

A 20-year-old nulligravida woman presented with bilateral cystic nodules of the vulva, diagnosed after simple excision as benign phyllodes tumor. Breast tissue, which also displayed fibrocystic changes, was also recognized. Follow-up at 2 months revealed no evidence of disease; however, 8 months after surgery she returned with a new mass in the vulva. This was excised and found to be recurrent phyllodes tumor. Although somewhat more cellular than the first lesions, it also was deemed to be benign based on histological features supported by flow cytometric DNA studies.

Ectopic cervical hamartomatous thymoma showing extensive myoid differentiation.

Ectopic 'hamartomatous' thymoma is a rare benign neoplasm. These tumours are found in the neck and are thought to be part of a spectrum of ectopic cervical thymic neoplasia. The clinical and histological features are discussed and the literature is reviewed. An attempt is made to explain in embryological terms why such lesions appear to occur more commonly on the left side.

Phakomatous choristoma of the eyelid. Immunohistochemical and electron microscopic observations.

BACKGROUND: A 13-month-old Hispanic boy underwent excision of a congenital inferonasal orbital mass arising from the right lower lid. Results of histopathologic examination of the tumor showed a phakomatous choristoma of the eyelid. An immunohistochemical and electron microscopic study of this rare, benign, congenital tumor of lenticular anlage was performed. METHODS: Immunohistochemistry was performed on 4-microns thick sections from paraffin-embedded tissue. Electron microscopy was performed on thin sections stained with uranyl acetate and lead citrate. FINDINGS: The cuboidal epithelial cells that comprise this choristoma showed strongly positive cytoplasmic staining with S-100 protein and vimentin and focally positive staining with a keratin cocktail (AE1/AE3). Electron microscopy showed the presence of numerous 10-nm whorled cytoplasmic microfilaments within degenerating epithelial cells. CONCLUSION: The immunoreactivity of this tumor to keratin and vimentin are newly described in this detailed clinicopathologic report and, together with its S-100 positivity, support the proposal that this tumor is of lenticular anlage. The authors hypothesize that the intracytoplasmic 10-nm intermediate filaments observed with electron microscopic examination within the epithelial cells that comprise this choristoma represent vimentin as detected by immunohistochemistry.

Follicular carcinoma with clear cell change arising in lingual thyroid.

A case of follicular carcinoma arising in the lingual thyroid of a 23-year-old woman is added to the 22 previous reports. The embryology and the clinical and pathologic differential diagnoses are discussed. Histologic criteria useful in diagnosing follicular malignancy in this area include local and vascular invasiveness, hypercellularity, mitotic activity, and necrosis. The use of the immunohistochemical marker thyroglobulin and electron microscopy are described for the first time and confirm a thyroid follicular cell origin.

Cutaneous ganglion cell choristoma. Report of a case.

We describe the histological, immunohistochemical, and ultrastructural findings of a cutaneous tumour composed of ganglion cells, without any other proliferating component. As ganglion cells are not normal components of the skin, we propose the term "ganglion cell choristoma" for this lesion. The differential diagnosis of related lesions such as cutaneous ganglioneuroma, well-differentiated metastases from neuroblastoma, autonomic ganglia entrapped by neurofibroma, and reactive processes, and the possible histogenesis of ganglion cell choristoma are discussed.

Correlative light and electron microscopic observations on ectopic neurons in the cerebellum of dreher mutant mouse.

The structure of ectopic neurons in the cerebellum of dreher mutant mouse was investigated by correlative light and electron microscopic observations. Tissue blocks were fixed in buffered aldehyde and embedded in a mixture of 2-hydroxypropyl methacrylate, Quetol 523, and methyl methacrylate. Sections at 0.4-0.5 microns in thickness were examined by electron microscopy after observation under a light microscope. By comparing the electron images with those of light microscopy in the same sites, the structures of ectopic cells were confirmed. Ectopic Purkinje cells were arranged with cell bodies that contained an oval, spherical or wrinkled nucleus without deep invagination and the thin layers of endoplasmic reticulum at the perinuclear regions. Granule cells were ectopically matured in the external granular layer and within the cluster at the cortical region. This method provides a useful procedure for understanding structures of the cerebellar neurons of the mutant.

SEM contribution to the morphological study of dental structures in ovarian cystic teratoma.

This study in scanning electron microscopy (SEM) was carried out to observe the possible pathologic aspect of five teeth grossly arranged in normal sequence and of their surrounding tissues, found inside an ovarian cystic teratoma. Though the general morphology of the teeth was nearly normal, several anomalies affected the different mineralized dental tissues such as enamel hypoplasia, irregular growth of cementum, altered predentin layer, and immature osteofibrous bony outgrowths.

Phakomatous choristoma: clinical, histopathologic, and ultrastructural findings in a 4-month-old boy.

A case of phakomatous choristoma of the lower eyelid is described. A survey of previously reported cases reveals a characteristic and consistent clinical and morphologic picture. Universally the patient presents in infancy with a rather small, firm, rubbery nodule attached to the lower edge of the inferior tarsal plate. Always present in the nasal aspect of the lower lid, the tumor is easily palpable. Recognition of this clinical picture may allow the ophthalmologist to suspect the appropriate diagnosis, but the final diagnosis should be based on the recognition of characteristic histopathology.

Exocrine pancreatic tissue in human liver: a metaplastic process?

Numerous microscopic foci of exocrine pancreatic tissue consisting of acini and small ductules were distributed throughout the liver of a 41-year-old patient with severe posthepatitic cirrhosis. The acinar cells were characterized by abundant zymogen granules on electron microscopic examination and a strong reaction with antibodies to alpha-amylase on immunoperoxidase staining. The pancreatic tissue was associated with proliferations of bile ductules within areas of fibrosis. No relationship with hepatocytes was observed. A metaplastic origin of the pancreatic tissue from the intrahepatic biliary epithelium is suggested.

Adrenal cortical adenoma in the spinal canal of an 8-year-old girl.

An ectopic adrenal cortical adenoma containing high levels of androstenedione but without clinically detectable virilizing effects was found in the spinal intradural space of an 8-year-old girl. The tumor, which was located at the L2 level, manifested itself clinically by a short history of bilateral leg pain. It was well encapsulated; therefore, total surgical removal was accomplished. The light microscopic appearance of the tumor was typical of adenomatous adrenal cortical tissue. Ultrastructurally, it also showed characteristic features of steroid-producing tumors, including very abundant smooth endoplasmic reticulum and giant mitochondria with tubulovesicular and circular cristae. Frozen tissue analyzed by radioimmunoassay was found to contain almost 20 times the normal tissue level of androstenedione. There was no elevation of cortisol or aldosterone levels in the tumor. Postoperative magnetic resonance imaging (MRI) scan of the retroperitoneum showed no abnormalities in the patient's adrenal glands. Serum androstenedione levels were normal. We postulate that the adenoma developed from congenital ectopic rests of intraspinal adrenal tissue. Although ectopic occurrence of adrenal cortical tissue has been recorded in other areas, neither such rests nor tumors developing from them have been previously reported within the spinal canal.

Heterotopic gastric mucosa of the small intestine in laboratory beagle dogs.

Out of the 365 young laboratory beagle dogs which were used in 17 toxicity bioassays, 15 cases (4.1%) were diagnosed as having congenital heterotopic gastric mucosa of the small intestine. Its incidence in the male dogs (12 cases out of 187) was higher than in the female dogs (3 cases out of 178). Grossly, the lesions were seen as an ulcerous focus of the small intestine, 25 cm to 88 cm proximal to the ileocecal valve. All of the lesions were quite similar histologically and electron microscopically to the normal gastric mucosa, which are composed of the surface mucous cells, chief cells, parietal cells, mucous neck cells and basal granulated cells of the stomach. And consequently, they were considered to be that of a congenital heterotopic tissue in the small intestine. The only morphological characteristic of these lesions different from the regular gastric mucosa was an association with the tubular structure seen in the basal region of these mucosal layers. These cells were considered to be of mucous-secreting cell origin because of secreting type III mucous evident from paradoxical concanavalin A or periodic acid Schiff stains. They seemed to be protecting the surrounding intestinal mucosa from gastric acid.

Hamartoma of the scalp with ectopic meningothelial elements. A distinctive benign soft tissue lesion that may simulate angiosarcoma.

Five cases of a distinctive benign soft tissue lesion of the scalp in patients ranging from 4 months to 40 years of age are described. Clinically, the lesions appeared as solitary, subcutaneous nodules suggestive of a cystic vascular malformation or other benign condition. Histologically, however, the lesions were characterized by a monotonous, pseudoinfiltrative proliferation of cuboidal epithelioid cells arranged in clusters within the dermis and subcutaneous tissue in intimate association with vessels, adipose tissue, and other connective tissue elements. A prominent feature in all cases was the presence of areas simulating freely anastomosing vascular channels lined by round to spindle-shaped, slightly hyperchromatic epithelioid cells reminiscent of angiosarcoma. Immunohistochemically, these cells were negative for factor VIII-related antigen and Ulex europaeus lectin but were strongly positive with vimentin and epithelial membrane antigen antibodies, this latter being in keeping with the immunohistochemical profile of meningothelial cells. The meningothelial nature of these cells was supported by the electron microscopic demonstration in one case of cells with complex, interdigitating cytoplasmic processes that were joined by scattered cell junctions and contained abundant intracytoplasmic intermediate filaments. The intimate admixture of meningothelial elements with haphazardly arranged connective tissue elements sets these lesions apart from cutaneous meningiomas and warrants their designation as hamartomas with an ectopic meningothelial component.

Phakomatous choristoma of the lower eyelid. A light and ultrastructural study.

This article documents the eighth reported case (to our knowledge) of a phakomatous choristoma, a rare congenital tumor of the lower eyelid of infants. Among the eight cases, there was no instance of tumor recurrence recorded nor was there any detectable postoperative eye defect, despite incomplete resection of the tumor in two patients. While usually clinically diagnosed as a dermoid cyst, the highly characteristic histologic features of this entity should allow more frequent recognition. Ultrastructural examination in our case provided additional evidence of its lenticular origin.

Nesidioblastosis arising from heterotopic pancreas and presenting with hypertension. A clinical, immunohistochemical and ultrastructural study.

A rare case of nesidioblastosis in an adult arising from heterotopic pancreas and presenting with hypertension is reported. To our knowledge it is the first case to be described in literature. The pathogenic mechanisms to explain hypertension are not clear. The stimulating action of glucagon on the adrenal gland or on peripheral beta receptors could be considered as hypothetical factors.

Fine needle aspiration cytology of recurrent ectopic meningioma.

Fine needle aspiration was performed on a recurrent extracranial meningioma in the left pterygomaxillary and temporal fossas in a 39-year-old woman. Cytologic and electron microscopic study of the aspirate and comparison to the previously resected specimen proved the recurrent nature of the lesion. The cytologic and ultrastructural findings in meningiomas are discussed with special consideration of the differential diagnosis in extracranial sites.

Extrameningeal meningiomas of the infratemporal fossa: diagnosis and treatment.

A presentation of two recently treated extrameningeal meningiomas of the infratemporal fossa will be augmented by a review of the literature on this subject. These tumors are quite rare, insidious in their presentation, and, as a benign tumor, require consideration of surgical treatment which causes the least possible functional disability. The natural history of these lesions and the surgical approach which has proved most successful in our hands will be discussed in some detail.

Adenocarcinoma of the upper esophagus arising in ectopic gastric mucosa. Two case reports and review of the literature.

Although ectopic gastric mucosa is often mentioned as a source of upper esophageal adenocarcinoma, few such cases have actually been documented. We report two cases and offer a review of the literature. Ectopic gastric mucosa in the upper esophagus is a relatively common congenital condition, but the risk of malignant transformation is extremely low. Ectopic gastric mucosa should be distinguished from Barrett's esophagus, an acquired condition with a well-documented predilection for developing adenocarcinoma.

Intracardiac ectopic thyroid.

The case of a patient with an intracardiac ectopic thyroid is reported. A lesion was found in a 25-year-old man and was diagnosed by two-dimensional echocardiography as a right intraventricular tumor. An operation was performed. Histologic and ultrastructural studies showed that the tumor was a thyroid mass. The origin of intracardiac ectopic thyroids is probably to be found in disturbances occurring early in embryogenesis.