Desmoplastic malignant melanoma. A clinicohistopathologic study of 25 cases

A clinical and histologic review of 25 patients with melanocytic lesions classified as desmoplastic malignant melanoma is reported. All of the lesions were located in sun-exposed sites. The average age was 61.2 years (range, 38 to 83), with a median age of 56. There were 14 female and 11 male patients. Desmoplastic malignant melanoma is a melanocytic and fibroblastic proliferation that occurs predominantly in the head and neck area. The bland constituent cells resemble fibroblasts and are often arranged in bundles or fascicles, which may be arrayed perpendicularly to the overlying epidermis. Enlarged and/or atypical cells are usually scattered among the spindled cells. Most, but not all, of the tumors (24 of 25 in this series) are associated with lentigo maligna or an atypical junctional melanocytic proliferation. Mitotic figures are always found within the constituent cells of the fibrous-appearing mass, and neurotropism may be present. Patients with desmoplastic melanoma typically present with a mass, which is occasionally associated with a pigmented lesion. The lesions in our series were deeply invasive to level IV or V. Lentigo maligna and a dermal fibroblastic-appearing mass containing atypical cells arranged in fascicles are the most common morphologic features found in desmoplastic melanoma. Follow-up data is available for 23 patients. The average length of follow-up was 2.7 years (range, 0.1 to 9 years). Eighteen patients were observed for 3 or more years. Twelve patients developed local recurrences, and five developed metastases; three of the patients with metastases had a local recurrence before the development of metastases. Three of the patients with metastatic melanoma died of tumor between 2 and 4 years after their initial excision. Eight of the 12 locally recurring lesions were either diagnosed initially as a benign lesion or histologic examination was not performed on the initial excision specimen. It appears that recurrence may be related to inadequate initial therapy.     

A malignant tumor of the vagina resembling synovial sarcoma: a light and electron microscopic study.

A malignant tumor arising in the upper lateral vaginal mucosa in a 24-year-old white woman, hitherto undescribed in the literature, was studied by light and electron microscopy. The main part of the tumor was epithelioid, forming a tubular or acinar pattern. At the periphery, the tumor cells were more spindly and formed sheets resembling fibrosarcoma. The tumor cells contained occasional material positive for mucicarmine, alcian blue, and PAS stains, and the nests of the cells forming acini were surrounded by reticulin fibers. The tumor ultrastructure consisted of a single type of cell with large cytoplasmic vacuoles and occasional perinuclear intracytoplasmic filaments. Slender long microvilli projecting into the lumina were also characteristic. Basal laminae were occasionally present around the acini. The findings suggested that the tumor was of mesenchymal origin, closely related to synovial sarcoma.     

Parathyroid carcinoma of the oxyphil cell type. A report of two cases, light and electron microscopic study

Parathyroid adenomas are subdivided into chief cell and oxyphil cell variants. However, the parathyroid carcinomas described thus far have been only of the chief cell type. Two cases of oxyphil cell carcinoma of the parathyroid gland are reported, with light and electron microscopic study. The patients presented apparent clinical hyperparathyroidism with x-ray finding of generalized fibrous osteitis and palpable parathyroid tumors. Initially, a pathologic diagnosis of parathyroid adenoma was made in both of them. However, in due course, pulmonary metastases developed in one patient and a local recurrence occurred in the other, 5 and 8 years after the primary operation, respectively. Review of the microscopic slides showed that both primary tumors met the criteria of parathyroid carcinoma. A matter of interest in both cases is that the neoplasms were composed principally of oxyphil cells. Electron microscopic study confirmed the existence of typical oxyphil cells packed with numerous mitochondria.     

A light microscopic and ultrastructural study of two cases of fibrolamellar hepatocellular carcinoma

We describe two cases of fibrolamellar hepatocellular carcinoma of the liver in two young women. Both patients presented with diffuse intra-abdominal metastases; nevertheless they had a survival of 28 and 32 months, respectively, which sustains the better prognosis of this neoplasm. Electron microscopy of one case confirmed the oncocytic features of the neoplastic cells and showed intra- and intercellular duct-like vacuoles with numerous microvilli containing a microfilament core that terminated in a terminal web, which represents an unusual aspect in the spectrum of differentiation of fibrolamellar hepatocellular carcinoma.     

Intracytoplasmic lumina of benign and malignant breast diseases--a light and electron microscopic study

Intracytoplasmic lumina (ICLs) of 70 cases with breast carcinoma and 29 cases with benign breast diseases were observed by light and electron microscopy. ICLs were morphologically divided into two types. Type A was characterized by the presence of secretory materials stained with eosin in the lumen and Type B by the cytoplasmic vacuoles under light microscope. Electron microscopic observation on Type A ICLs showed numerous filiform microvilli projecting towards the lumen and various amounts of secretory materials in the lumen. Type B of ICLs only had scanty and short microvilli and rarely secretory materials in the lumen. The results indicated that: 1. The frequency of ICLs in breast cancer was significantly higher than that in benign breast disease (P less than 0.01). 2. The frequency of ICLs in breast cancer showed strong negative correlation with its histological grades but not with its histological types. 3. ICLs had similar frequency under both light and electron microscopes. As a relatively specific structure in breast carcinoma cells, ICLs may be helpful in the diagnosis of breast carcinoma and establishment of the breast origin for metastatic carcinoma.     

Glassy cell carcinoma of the uterine cervix. A light and electron microscopic study of five cases

Five cases of glassy cell carcinoma of the uterine cervix were examined by light and electron microscopy. Light microscopic features included areas of large cells with ground glass and granular cytoplasm, distinct borders, prominent stromal inflammation, and lack of apparent squamous or glandular differentiation. Two neoplasms were associated with separate foci of squamous cell carcinoma in situ and one with endocervical adenocarcinoma. Electron microscopy showed a predominant cell type with cytoplasmic filaments, dilated rough endoplasmic reticulum, Golgi complexes, and large nuclei with complex nucleoli. In some cells there were tonofibrils and well developed desmosomes. The neoplasm of one patient showed poorly developed intracellular lumina. These observations were interpreted to indicate that glassy cell carcinoma is associated with and demonstrates both glandular and squamous differentiation. It is, therefore, properly classified as a type of poorly differentiated adenosquamous carcinoma, which likely develops from the subcylindric reserve cell. The results of this experience reaffirms its poor prognosis.     

Metastatic cystosarcoma phyllodes: a light and electron microscopic study.

Two cases of metastatic cystosarcoma phyllodes, one in lung and the other in axillary lymph nodes, were studied with the light and the electron microscopes. The malignant element of these tumors appears to be a poorly differentiated mesenchymal cell. No evidence supporting the presence of epithelial cells was found. The tumor metastatic to the axilla exhibited intracellular virus-like particles similar to those described in adenocarcinoma of breast and other sarcomas.     

Benign vaginal rhabdomyoma: a light and electron microscopic study.

A benign vaginal rhabdomyoma from a 49-year-old woman was examined by light and electron microscopy. While many of the ultrastructural features conformed to those noted in previously described rhabdomyomas, certain features are described for the first time. These include attachment plaques between cells enclosed within a common basement membrane, cytoplasmic bodies, and peripheral couplings. Finally, the literature is reviewed and the reported cases of rhabdomyoma are divided into adult and fetal types based upon light microscopic criteria.     

Hyperplastic foci in precancerous rat liver: light microscopic and electron microscopic study.

4-Dimethylaminoazobenzene was fed to Wistar-derived, male, albino rats after hepatic siderosis had been induced by including ferric citrate in the diet. Iron-free foci of hepatocytes developed and this characteristic enabled them to be recognized macroscopically in the brown parenchyma. Five such lesions, each 1 mm or less in diameter, were studied by light and electron microscopy. The cells in the foci were larger than those surrounding the foci and had a granular and moderately basophilic cytoplasm. Ultrastructurally, the cells closely resembled normal hepatocytes. They possessed well-developed rough endoplasmic reticulum, numerous free ribosomes, peroxisomes, bile canaliculi, and cytoplasmic junctional complexes, but only small stores of glycogen were observed. Occasional ferritin-laden lysosomes persisted in some cells. These foci were regarded as hyperplastic. Possibly, they evolved into hyperplastic nodules either of the basophilic or vacuolated type. These foci should be clearly distinguished from hyperbasophilic foci that consisted of very poorly differentiated cells.     

Primary carcinoid of the kidney: light and electron microscopic study.

A case of an asymptomatic primary renal carcinoid tumor in a 61-year-old male is presented. The tumor was large with extensive hemorrhagic necrosis. Metastases were present in para-aortic lymph nodes. Ultrastructurally, dense core granules and masses of cytoplasmic filaments, including tonofilaments, were seen. The granules were faintly argyrophilic. The relevant literature is reviewed.     

Primary rhabdomyosarcoma of the kidney. A light microscopic, immunohistochemical, and electron microscopic study

Primary rhabdomyosarcoma of the kidney is a rare and highly aggressive tumor in the adult population. A case is reported in a 70-year-old woman with the diagnosis confirmed by immunohistochemistry and electron microscopy. This is the first case studied using the immunoperoxidase technique and the second with electron microscopic examination. To make a diagnosis of primary sarcoma, of the kidney, three criteria must be met: (1) a metastatic sarcoma must be ruled out; (2) the tumor must arise from renal parenchyma; and (3) a sarcomatoid variant of renal cell carcinoma needs to be excluded. The literature is reviewed and available clinical and pathologic details are summarized.     

Primary anorectal malignant melanoma: report of two cases

Primary anorectal malignant melanoma is a fairly uncommon but highly malignant disease. It is sometimes mistaken for benign conditions such as hemorrhoids or rectal polyps. Here we describe two cases of primary malignant melanoma of the rectum: in one patient a wide local excision (WLE) was performed and in the other an abdominoperineal resection (APR), both with curative intent. Both patients developed systemic recurrences and died of their disease at 24 and 10 months, respectively. In conclusion, the prognosis of anorectal melanoma is poor, irrespective of surgical treatment. WLE is the first choice for primary anorectal melanoma, while APR should be reserved for those cases where complete transrectal tumor resection is technically impossible.     

Glycogen-rich adenocarcinoma of minor salivary glands. A light and electron microscopic study.

A malignant glycogen-rich adenocarcinoma of palatal salivary glands is reported. Histopathology revealed nonencapsulated nests and cords of polyhedral cells showing voluminous clear cytoplasms and cellular pleomorphisms, separated by fine vascular septae. Small and large ducts were infrequently seen showing apparent transition of large ducts into clear cells. The tumor cells were PAS- and Best-carmine positive, diastase soluble, and mucicarmine and Alcian-blue negative. Ultrastructurally, the tumor cells were arranged in solid nests and cords of electron-lucent cells surrounding single or multiple lumina, and surrounded by basement lamina. Occasional fusiform electron-dense cell processes were present beneath the basement lamina. The electron-lucent cells were joined by junctional complexes, contained intracytoplasmic canals, and were filled with massive accumulations of beta glycogen particles. The electron-dense processes contained interlacing whorls of fine filaments and exhibited peripheral focal densities. The findings suggest that this glycogen-rich malignant tumor is of epithelial origin most probably of ductal cells.     

Malignant oncocytoma of the parotid gland. A light and electron microscopic study.

A case malignant oncocytoma of the parotid gland occurring in a 91-year-old man is reported. The tumor recurred 10-months and 2 1/2 years after the primary excision. Both primary and recurrent tumors exhibited an infiltrative pattern. The histologic appearance of the original tumor and the recurrent lesion were similar, but there were areas of increased mitotic activity and pleomorphism in the latter. Ultrastructural examination of the recurrent tumor revealed that the cytoplasm was packed with mitochondria. The fine structure was, for the most part, similar to the benign variant reported previously. In the present tumor, however, intercellular spaces were more prominent and a basal lamina was not observed. The malignant oncocytoma occurs both in major and minor salivary glands. The tumor mostly affects the older age group, but the biologic behavior cannot be evaluated fully because of the paucity of cases reported and the lack of follow-up information.     

Glycogen-rich Clara cell-type bronchiolo-alveolar carcinoma: light and electron microscopic study.

A clear cell type of bronchiolo-alveolar carcinoma removed from the lung of a 63-year-old man was studied by light and electron microscopy. The tumor was composed exclusively of Clara cells identified by the presence of secretory granules, an abundance of granular endoplasmic reticulum, a moderate number of mitochondria and prominent Golgi complexes. The tumor cells were tall columnar and had clear cytoplasm due to the presence of large pools of intracytoplasmic glycogen. This feature has not heretofore been described. Ultrastructural features distinguishing this tumor from benign clear cell tumors of the lung and clear cell carcinomas of the kidney are described.