Sarcomatoid carcinoma of the skin: report of a case.

We report the histological, immunohistochemical and ultrastructural findings of an exophytic cutaneous tumor composed of a mixture of typical basal cell carcinoma (BCC) and malignant fibrous histiocytoma. Nine previously reported carcinosarcomas of the skin are reviewed. We prefer the term "sarcomatoid carcinoma" for this rare neoplasm. Only the BCC showed a positive immunoreaction to cytokeratin; the sarcomatous component was negative, but it did express vimentin, and, focally, smooth-muscle-specific actin and KP1 (CD68). Both components showed p53 immunostaining.

Hyalinizing trabecular carcinoma of the thyroid gland: report of two cases of follicular cell thyroid carcinoma with hyalinizing trabecular pattern.

Recently tumors have been reported that have an architectural pattern and cellularity similar to hyalinizing trabecular adenoma and show either parafollicular differentiation or histological findings suggestive of malignant neoplasm of the follicular cells. This study describes two cases of thyroid carcinoma of follicular cells that displayed a hylinizing trabecular pattern. The first case was a 25-year-old euthyroid woman with a cold thyroid nodule in the right lobe. On fine needle aspiration a diagnosis of papillary carcinoma was rendered. The thyroidectomy disclosed a 2-cm, firm, brown, encapsulated tumor in the right lobe. The tumor had a growth pattern and cytologic features similar to those described in hyalinizing trabecular adenoma. The differences between these neoplasms were the presence of mitotic figures, prominence of the nucleolus, capsular blood vessel invasion, and microtubule groups in the endoplasmic reticulum. The second case was a 19-year-old euthyroid woman with a cold thyroid nodule in the left lobe. A cytologic diagnosis of follicular proliferation was rendered. A 4-cm, firm, whitish, encapsulated nodule was found in the left lobectomy. The tumor cells were arranged in two clear-cut patterns: a trabecular hyalinizing pattern with a small focus of papillary growth, and a follicular pattern. These findings confirm the existence of malignant thyroid tumors with a hyalinizing trabecular pattern and illustrate the nonspecificity of this peculiar pattern, since it may also be seen in papillary carcinomas of the thyroid. The relationship between hyalinizing trabecular adenoma and papillary carcinoma of the thyroid is commented on.

Mesenchymal chondrosarcoma of the retroperitoneum. Report of a case diagnosed by fine needle aspiration biopsy with immunohistochemical, electron microscopic demonstration of S-100 protein in undifferentiated cells.

BACKGROUND: Mesenchymal chondrosarcoma (MC), first described in 1959 by Lichtenstein and Bernstein, is an uncommon tumor of the soft tissues and bone defined by the coexistence of nests of well-defined cartilaginous tissue within a proliferation of primitive mesenchymal cells. CASE: A 27-year-old, white female consulted a physician for a left lumbar mass associated with sciatica-type pain, asthenia, anorexia and weight loss. Abdominal computed tomography showed a 20-cm, retroperitoneal neoplasm that occupied the lower half of the left abdominal flank. Fine needle aspiration biopsy showed clusters of small round cells mixed with islets of mature cartilage. Immunomarking for electron microscopy, carried out with 15 nm of A protein/colloidal gold, showed specific immunoreactivity to S-100 protein in the nuclear chromatin, nucleoli, Golgi apparatus, plasma membrane and cytosol of cells with more developed organelles. CONCLUSION: The diagnosis of MC rests on recognition of the biphasic component of small, undifferentiated cells and cartilage islets. In aspirates with only undifferentiated cells, demonstration of ultrastructure-specific immunoreactivity to S-100 protein may contribute to the final diagnosis.

Diffuse tenosynovial giant cell tumor of soft tissues. Report of a case with cytologic and cytogenetic findings.

Extraarticular diffuse tenosynovial giant cell tumor is an unusual lesion the cytologic picture of which has not been discussed much in the literature. Fine needle aspiration biopsy of a nonpainful mass in the right shoulder in an 18-year-old woman revealed a highly cellular lesion consisting of polygonal cells and multinuclear giant cells with scant nuclear pleomorphism and a marked tendency toward xanthomization. Electron microscopy identified two basic cell populations among many intermediate forms: cells with scant filopodia and abundant ribosomes and cells with well-developed prolongations and numerous mitochondria, lysosomes and lipid drops. The karyotype of the tumor cells obtained from a surgically excised specimen showed a clonal population with 45, XX, t(1;2) (pter->p22::q24->pter), t(1:14)(qter->p13::q13->ter). The cytologic differential diagnosis included other tenosynovial lesions containing xanthomatous cells. Cytogenetic findings are discussed in relation to chromosomal alterations previously found in related lesions (nodular tenosynovitis and pigmented articular villonodular synovitis).

Papillary cystic neoplasm of the pancreas with liver metastasis coexisting with thyroid papillary carcinoma.

BACKGROUND: Papillary cystic neoplasm of the pancreas is an uncommon neoplasm that usually appears to be benign or to have a very low potential for metastasis. We report a case of a patient with papillary and cystic neoplasm of the pancreas, which metastasized to the liver and concomitantly presented a stage I thyroid papillary carcinoma. CASE DESCRIPTION: The patient was a 38-year-old woman with a 12-year history of abdominal pain. She was first admitted to the hospital 3 years after symptoms began, and an exploratory laparotomy revealed a pancreatic cystic lesion that was diagnosed as a pancreatic pseudocyst, which drained by cystojejunosotomy. Nine years after onset, a stage I thyroid papillary carcinoma was excised. One-and-a-half years later, the patient was readmitted to the hospital for evaluation of a palpable abdominal mass. Abdominal computerized axial tomography disclosed a large pancreatic tumor and two nodular lesions of the liver. Papillary cystic neoplasm of the pancreas was diagnosed by cytologic, histologic, and ultrastructural studies of samples obtained directly from the pancreatic mass using fine-needle aspiration biopsy. The patient underwent palliative chemotherapy with mitomycin C, 4-epiadriamycin, and 5-fluorouracil. One year after this treatment began, a computerized axial tomography scan showed persistence of the pancreatic mass, with more prominent cystic spaces, increase in size and in number of the lesions in the liver, slight increase in the lesion of the right ovary, and a new lesion that also had solid and cystic areas in the spleen. CONCLUSION: The pathologic and clinical features of patients with papillary cystic neoplasm of the pancreas, based on tumoral extension, reveal localized tumors (88.2%), tumors with local infiltration or recurrence (6.2%), and tumors with metastasis at a distance (5.6%). Although strong similarities exist among the three groups, there are certain differences in age of presentation, previous clinical diagnosis of pseudocyst, and tumor location.

Fine needle aspiration cytology of primary soft tissue tumors. Morphologic analysis of the most frequent types.

We reviewed 98 cases of fine needle aspiration of soft tissue tumors with histologic confirmation performed during an eight-year period and propose a working morphologic classification based on the most prominent cytologic features. Six main tumor groups are recognized: myxoid, round cells, spindle cells, pleomorphic cells, polygonal cells and well differentiated. We believe that this classification allows recognition of the most common soft tissue tumors while helping with the differential diagnosis of other neoplasia, primary or secondary, with similar morphology and a similar presentation.

Fine needle aspiration of peripheral neuroepithelioma of soft tissues.

Peripheral neuroepithelioma of soft tissue is a malignant primitive neuroectodermal tumor that appears both in children and adults and usually has a poor outcome. Fine needle aspiration on two patients with tumors in the lower limbs showed small round cells with unipolar processes and a tendency to form Homer-Wright rosettes. The cells had a round to oval nucleus with fine chromatin, up to four small, conspicuous nucleoli and vacuolated, periodic acid-Schiff-positive cytoplasm. The diagnosis was supported by electron microscopic study of the aspirate, which showed features of neuroblastic differentiation (i.e., neurosecretory granules), and by histologic, immunohistochemical and cytogenetic study of the resected tumors.

Fine needle aspiration in myxoid tumors of the soft tissues.

Myxoid tumors of soft tissues constitute a histogenetically heterogeneous group of lesions, both benign and malignant, that show an overproduction of mucopolysaccharide substances. A correlative fine needle aspiration (FNA) cytologic and histologic study was performed on 16 such cases (3 intramuscular myxomas, 2 lipoblastomas, 6 myxoid liposarcomas, 4 myxoid malignant fibrous histocytomas [MFHs] and 1 extraskeletal myxoid chondrosarcoma), with electron microscopic examination of the aspirate in 4 cases. FNA of all tumors produced a gelatinous material. Smears from all but one of the tumors had a granular myxoid background substance that stained blue to blue-red with the Diff-Quik stain; the exception was the extraskeletal myxoid chondrosarcoma, whose smears stained intensely blue-red to red. On light microscopy, only lipomatous tumors had distinctive cells with diagnostic value: the lipoblasts. Although the arrangement of lipoblasts in lipoblastomas differed somewhat from that found in myxoid liposarcomas, clinical data were important for making a definitive diagnosis. Intramuscular myxomas generally showed a low cellularity composed of fibroblastlike cells with no cytologic atypia. Myxoid MFHs were composed of fibroblastlike cells and macrophagelike cells; the elongated cells with slight-to-moderate nuclear atypia predominated in tumors of low-grade malignancy, while polygonal or round cells with one or more nuclei and marked nuclear atypia predominated in high-grade tumors. Although extraskeletal myxoid chondrosarcoma was mainly differentiated from low-grade myxoid MFH by its metachromatic matrix, ultrastructural studies showed the distinctive distended cisternae with microtubular aggregates in the extraskeletal myxoid chondrosarcoma, thus contributing to the definitive diagnosis.

Retroperitoneal ganglioneuroblastoma. Report of a case diagnosed by fine needle aspiration cytology and electron microscopy.

Fine needle aspiration performed on a large retroperitoneal mass in a 12-year-old boy showed neuroblasts in different stages of maturation intermingled with ganglion cells, leading to a cytologic diagnosis of ganglioneuroblastoma. This diagnosis was supported by electron microscopic study of the aspirate, which showed features of neuroblastic differentiation, and by histologic study of the resected tumor.

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.