Cytomorphology of lipomatous tumors of soft tissue

OBJECTIVE: To evaluate the cytomorphologic features of benign and malignant lipomatous tumors of soft tissue on fine needle aspirates (FNA) and determine if the variants of liposarcoma could be identified. STUDY DESIGN: FNA of histologically documented benign (51 cases) and malignant (39 cases) lipomatous tumors were reviewed. Twenty-six of the 51 FNA from lipomas and 34 of the 39 FNA from malignant lipomatous tumors were satisfactory for evaluation. RESULTS: FNA from 26 cases of lipomas were cellular, with lobulated, fibroadipose tissue. Thin and thick capillaries were seen in 92% and 65% of cases, though a chicken wire vascular pattern was seen in only 4 cases (15%). A cytodiagnosis of liposarcoma could be made in 23 cases (88%), and these could be further subtyped into well-differentiated (4 cases), myxoid (8), pleomorphic (4), round cell (3) and liposarcoma, ?type (4). Only 50% of the well-differentiated liposarcomas, 3 of the 10 pleomorphic liposarcomas and 8 of the 17 myxoid liposarcomas were diagnosed as such on FNA. Cytologic diagnosis of the remaining 9 cases of myxoid liposarcoma were pleomorphic liposarcoma (1); liposarcoma, ?type (3); malignant mesenchymal tumor (1); suspicious for malignancy (2); and benign (2). There were no false positives, but there were 3 false negative cases (1 well-differentiated and 2 myxoid liposarcoma). CONCLUSION: Lipomas can be diagnosed readily. Arborizing vessels can be seen in lipomas and should be interpreted with caution. Subclassification of liposarcomas on FNA is possible but not very reliable. Myxoid liposarcomas pose a problem, and aspirates from them can mimic a wide range of morphologic subtypes. The role of FNA in identification of variants of liposarcoma is limited.     

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.     

Spindle cell lipoma of the oral cavity. Report of a rare intramuscular case with fine needle aspiration findings

BACKGROUND: Spindle cell lipoma (SCL) is a benign neoplasm characterized by a mixture of mature fat, bland spindle cells and wiry collagen in a variably myxoid background. Oral SCLs are rare, and only four cases of intramuscular SCL exist in the literature. We report the first case of intramuscular SCL of the oral cavity with fine needle aspiration (FNA) findings. CASE: A 61-year-old woman presented with a 3-cm mass in the right gingivobuccal sulcus. Papanicolaoustained FNA smears were hypocellular and contained loose collections of spindle cells in a myxoid background, numerous mast cells, rare capillary fragments and portions of skeletal muscle. The spindle cells had mild nuclear enlargement, focal nuclear irregularities, rare intranuclear inclusions and occasional small nucleoli. No lipoblasts or mitoses were identified. There was intermingling of the spindle cells with the skeletal muscle fragments. CONCLUSION: Intraoral SCL is a rare lesion but should be considered in the differential for a benign spindle cell neoplasm in the oral cavity. Clues to diagnosis on cytology include mature fat, bland spindle cells, a myxoid background and mast cells.     

Cytodiagnosis of extraosseous mesenchymal chondrosarcoma of meninges: a case report

BACKGROUND: Extraosseous mesenchymal chondrosarcoma (MC) is a rare neoplasm. Most reports in the literature are based on histologic diagnosis. Cases diagnosed on the basis of cytologic features are few. CASE: A 30-year-old woman presented with complaints of headache, vomiting and swelling in the right temporal region for the previous 2 months. Fine needle aspiration (FNA) smears showed scant material consisting mainly of monomorphic small round cells with granular cytoplasm and central round nuclei lying in a background of myxoid matrix. Occasional giant cells were also seen. Cells were periodic acid-Schiff negative. One of the smears showed a tiny fragment of cartilaginous component. A provisional diagnosis of extraosseous MC was made. Peroperatively the mass was arising from meninges and the diagnosis was confirmed by histology. CONCLUSION: Extraosseous MC should be considered in FNA smears showing small round cells in a myxoid background. Demonstration of cartilage and a correlation of clinical presentation and imaging studies with cytologic findings are important.     

Hemangiopericytoma in a male breast. Report of a case with cytologic, histologic and immunochemical studies

A hemangiopericytoma in a male breast was studied by fine needle aspiration (FNA) biopsy. The FNA smears contained tissue clumps showing knob-like formations of atypical cells, spindle-shaped cells and fragments of capillaries lined by normal endothelial cells. Immunocytochemical study showed a positive reaction for vimentin, but a negative reaction for desmin and keratin. Staining for Factor VIII was positive only in the capillaries and endothelial cells. The cytodiagnosis was "mesenchymal tumor." Histopathologic study of the mastectomy specimen made the final diagnosis of hemangiopericytoma. While FNA cytology and immunocytochemistry cannot make a definitive diagnosis of this rare vascular tumor, they can be decisive in planning the surgical treatment, as in the present case.     

Low grade fibromyxoid sarcoma: report of a case with fine needle aspiration cytology and histologic correlation

BACKGROUND: Low grade fibromyxoid sarcoma has been fully described histologically; however, the fine needle aspiration (FNA) cytologic findings are scantily defined, and the distinction from other benign and malignant soft tissue tumors can be difficult. CASE: We examined FNA cytologic material from a slowly growing, large chest wall mass in a 28-year-old woman. The surgical specimen was processed for routine histology and immunohistochemical studies. The cytologic smears were adequately cellular, showing spindly cells with uniform, elongated nuclei; small, inconspicuous nucleoli; and scanty, wispy cytoplasm associated with myxoid material. No significant nuclear pleomorphism or mitoses were noted. The excised tumor was well circumscribed, focally infiltrating the surrounding muscles. The cut surface was variable, featuring fibrous, solid, fleshy and myxoid areas. Microscopically, the solid, fibrous areas displayed increased cellularity with storiform, intersecting and parallel patterns. In the myxoid areas the cells grew in a haphazard fashion and appeared floating in abundant mucoid matrix associated with a capillary vascular network similar to the chicken-wire pattern seen in cases of myxoid liposarcoma. The tumor cells were spindly, with fusiform, uniform nuclei. Focal, moderate nuclear pleomorphism was noted. The mitotic index was low. The tumor cells were positive for vimentin, alpha-1-antitrypsin and lysozyme and negative for S-100, actin, desmin and CD34. CONCLUSION: Although low grade fibromyxoid sarcoma is a rare neoplasm, it should be recognized and distinguished from other soft tissue tumors because of its low malignant potential. The definitive FNA cytologic diagnosis can be challenging but is possible if the tumor is adequately sampled, with multiple passes from different areas. Clinical and radiologic correlations are of great help. All spindle cell tumors with myxoid changes, such as myxoid liposarcoma, myxofibrosarcoma, cellular myxoma, myxoid leiomyosarcoma and peripheral nerve sheath tumors, should be considered in the differential diagnosis. In contrast to the cytologic features, the histologic findings are characteristic and well established.     

Myoepithelioma of the parotid gland initially diagnosed by fine needle aspiration cytology and immunocytochemistry: a case report

BACKGROUND: Myoepithelioma is a rare, benign tumor of the salivary gland, most commonly affecting the parotid gland. Although the cytologic features of myoepithelioma are documented in a few case reports, it has rarely been diagnosed preoperatively by fine needle aspiration (FNA) cytology. CASE: A 33-year-old man presented with a left parotid swelling 2.5 cm in diameter and of about 5 years' duration. FNA smears showed bundles of spindle-shaped cells as well as plasmacytoid and stellate cells in sheets and dissociated forms. A few cells had nuclear grooves, and occasional cells showed intranuclear cytoplasmic inclusions. In May-Grünwald-Giemsa-stained smears, most of the cells had reddish cytoplasm. Red to purple, myxoid matrix was present as a scanty fibrillar substance and as globules surrounded by tumor cells vaguely reminiscent of adenoid cystic carcinoma. A cytodiagnosis of myoepithelioma was given and corroborated by immunocytochemical staining, which revealed a positive reaction for vimentin, smooth muscle actin and S-100 protein. Epithelial membrane antigen yielded a negative reaction except for a few plasmacytoid cells with weakly positive staining. Histopathology of the resected tumor and immunohistochemical staining confirmed the cytodiagnosis of myoepithelioma. CONCLUSION: FNA cytologic features together with immunocytochemical studies on smears can offer a preoperative diagnosis of myoepithelioma.     

Osteoclastomalike giant cell tumor of the parotid gland: report of a case with fine needle aspiration diagnosis

BACKGROUND: Osteoclastomalike giant cell tumor of the parotid gland has been reported rarely. The tumor has occurred rarely at many sites, such as thyroid, pancreas, soft tissue, breast, skin, heart, colon, lung, kidney, ovary and bladder. The exact origin of the tumor is unclear. However, osteoclastlike giant cells have been considered either part of a stromal process reactive to a neoplasm or a component of a primary neoplasm. CASE: A 35-year-old female presented with a mass in the left parotid gland clinically diagnosed as a pleomorphic adenoma. Fine needle aspiration (FNA) was advised before surgical excision. FNA smears revealed numerous osteoclastlike, multinucleated giant cells and many malignant-looking mononuclear cells. The smears were diagnosed as positive for malignancy, suggestive of osteoclastomalike giant cell tumor. The tumor was excised, and histopathologic study confirmed the cytologic diagnosis. CONCLUSION: The cytologic findings of osteoclastomalike giant cell tumor of the parotid gland have not been previously reported. FNA aided the diagnosis and planning of treatment. FNA is important in the diagnosis of parotid tumors.     

Fine needle aspiration of extramedullary myeloid cell tumor in myelodysplastic syndrome. A report of three cases.

BACKGROUND: Soft tissue tumors are rare in myelodysplastic syndrome (MDS), and the role of fine needle aspiration (FNA) cytology in their diagnosis has not been explored. CASES: Two patients with refractory anemia with excess blasts in transformation (RAEB-t) developed soft tissue swellings during the course of the illness. In a third patient, soft tissue swelling was a presenting feature. The swellings in all three cases were diagnosed as extramedullary myeloid cell tumor (EMT) on FNA and showed increased blasts (10-14%), dyspoietic changes, Auer rods and monocytosis. CONCLUSION: Soft tissue tumors appearing in MDS are likely to be EMTs. FNA is therefore particularly valuable in their diagnosis as morphology, cytochemistry, immunophenotyping and flow cytometric analysis of hematopoietic cells are best studied on aspirated material. We suggest that FNA be preferred over excisional biopsy for the diagnosis of soft tissue swellings in MDS.     

Granular cell tumor of the parotid gland. A case report

BACKGROUND: Granular cell tumor (GCT) is a relatively uncommon soft tissue tumor of putative Schwann cell origin. This tumor can occur in multiple sites as a small, nontender nodule, but the parotid gland is unusual, and only several cases have been reported. CASE: A 46-year-old woman presented with a slowly growing mass in the left preauricular region for three years. Imaging studies confirmed a nodular lesion in the superficial lobe of the left parotid gland. Fine needle aspiration (FNA) cytology revealed scattered cellular clusters and single cells with abundant granular cytoplasm and indistinct cell borders. Background exhibited eosinophilic, granular, cytoplasmic material, and some scattered naked nuclei were also noted. Histologic examination with supportive immunohistochemical and ultrastructural studies confirmed GCT. CONCLUSION: GCT of the parotid gland is very unusual. Recognition of this tumor is important to make a definitive diagnosis before an operation. FNA is useful procedure in GCT of parotid gland for a preoperative diagnosis and proper treatment.     

Retroperitoneal mesenchymal chondrosarcoma. Report of a case diagnosed by fine needle aspiration cytology

An unusual case of retroperitoneal mesenchymal chondrosarcoma diagnosed by fine needle aspiration (FNA) biopsy is described. CT-guided FNA of a mass arising in retroperitoneal soft tissues yielded an amorphous, myxoid material containing two distinct and separate populations of tumor cells. One was an undifferentiated, monomorphic, small cell component with granular cytoplasm and round central nuclei. The second population was an overtly malignant chondroid component scattered within an abundant myxoid matrix showing foamy cytoplasm, marked nuclear pleomorphism and frequent multi-nucleation. These cytologic findings were distinctive and similar to the histologic findings. The differential diagnosis and the possible pitfalls in the FNA diagnosis of this relatively rare tumor are discussed.     

Fine needle aspiration biopsy of well-differentiated liposarcoma of the neck in a young female. A case report.

BACKGROUND: Well-differentiated liposarcomas are low grade, nonmetastasizing, malignant neoplasms composed primarily of mature adipose tissue. They are uncommon in the head and neck. CASE: A 24-year-old female presented to the ears, nose and throat clinic for evaluation of a recent, rapidly growing neck mass on the right side. Fine needle aspiration (FNA) biopsy of the mass showed that the smears had fragments of connective tissue with a mixture of mature-appearing fat traversed by bands of fibrous collagen and vessels. Nuclei within the fat and fibrous bands were mildly irregular, hyperchromatic and enlarged, with one or two small nucleoli. Infrequently present but readily identified, lipoblasts were scattered throughout the aspirate smears. A diagnosis of "atypical lipomatous neoplasm" was rendered. Subsequently, the mass was surgically removed. On histologic examination, the tumor was a well-differentiated liposarcoma. CONCLUSION: FNA biopsy of well-differentiated liposarcomas in the head and neck can present difficulties in the classification and diagnosis of this neoplasm.     

Fine needle aspiration diagnosis of extraadrenal myelolipoma presenting as a pleural mass. A case report

BACKGROUND: Myelolipoma is a benign tumor composed of mature adipose tissue and hematopoietic cells. Although they are commonly found in adrenal glands, extraadrenal myelolipomas (EMLs) are rare but well documented. They have been found in various sites, including mediastinum, liver, stomach, lungs, pelvis, spleen, retroperitoneum, presacral region and mesentery. EMLs must be distinguished from extramedullary hematopoieses, which are also composed of hematopoietic elements but may lack adipose tissue and are associated with anemia and marked bone marrow hyperplasia. CASE: We describe a case of a pleura-based, extraadrenal myelolipoma in a 53-year-old female with unremarkable bone marrow findings that were initially encountered on fluoroscopy-guided fine needle aspiration (FNA). One year later the mass was removed via open thoracotomy. It showed typical EML features histologically. CONCLUSION: EML manifests on aspiration cytology as a cellular specimen with numerous trilineage hematopoietic cells and a variable proportion of mature adipose cells. To our knowledge, FNA cytology of EML has not been found in this location before. Aspiration biopsy offers a simple and reliable method for the diagnosis of EML in the presence of appropriate clinical settings.     

Fine needle aspiration cytology of perineurioma. Report of a case with histologic, immunohistochemical and ultrastructural studies

The fine needle aspiration (FNA) findings are presented for a case of perineurioma, a benign soft tissue tumor composed of perineurial cells, which are epithelial-like and ensheath the endoneurial connective tissue space of nerve fibers. A subcutaneous FNA performed on a posterior thigh mass of a 14-month-old boy produced a specimen consisting of numerous spindle-shaped tumor cells with bipolar cytoplasmic extensions and occasional pseudosignet-ring cells in a prominent myxoid background. Cytologically, a diagnosis of benign myxoid tumor was made. Histologic examination of the resected tumor revealed the characteristic features that have been described for perineurioma; the diagnosis was confirmed with immunocytochemical and ultrastructural studies. Perneurioma should be included in the differential diagnosis of benign myxoid neoplasms seen in FNA biopsy specimens.     

Oropharyngeal chordoma diagnosed by fine needle aspiration: a case report

BACKGROUND: Due to its rarity, chordoma may be difficult to differentiate from other neoplasms with a similiar myxoid background. We describe a case of chordoma involving the oropharynx inferiorly that was diagnosed by transoral fine needle aspiration (FNA) cytology (FNAC) and confirmed by histologic studies. This appears to be 1 of the few reported applications of FNA in the diagnosis of chordoma of the oropharynx in the English-language literature. CASE: A 50-year-old male presented with nocturnal dyspnea and rare hemoptysis for 6 months. A hypodense mass was located in the left posterior side of the oropharynx. FNAC of the mass showed classic physaliferous cells with a bubbly appearance and myxoid fibrillary background. The aspirate was reported as "myxoid tumor suggestive of chordoma," as confirmed by histopathologic investigation of the excisional biopsy. CONCLUSION: The cytologic features of chordoma are quite characteristic, especially on May-Grünwald-Giemsa (MGG)-stained slides. The cytoplasmic vacuoles of the physaliferous cells and the mucoid matrix of the tumor become conspicuous on MGG staining. When Papanicolaou staining is used as the only staining procedure, the cytoplasmic vacuoles of the physaliferous cells and mucoid matrix of chordomas may be overlooked. The differential diagnosis of myxoid tumors is of utmost importance for therapy and prognosis.     

Lipomatous lesions of the parotid gland. Potential pitfalls in fine needle aspiration biopsy diagnosis

Nine cases of benign fatty tumors of the parotid studied initially by fine needle aspiration (FNA) biopsy and subsequently diagnosed by open biopsy were reviewed. All lesions presented as enlargements of the parotid gland. The cytologic diagnoses were correct in only five of the nine cases. While four of six FNA samples from lipomas were correctly diagnosed by cytology, the other two samples were classified as inadequate. Three cases of diffuse infiltration of the parotid by mature-appearing adipose tissue were cytologically characterized as "no diagnostic change" in two cases and sialosis in one case. The clinical, radiologic, cytologic and histologic features of these tumors are described to increase the familiarity of cytologists with these lesions, which may prevent unnecessary surgical intervention in some patients.     

Fine needle aspiration cytology of adult perineal rhabdomyosarcoma: a case report

BACKGROUND: Adult perineal soft tissue sarcomas are rare. Fewer than 30 cases have been reported, and all were diagnosed after surgical resection by histologic examination. Below we report a case in which the diagnosis was established preoperatively by fine needle aspiration (FNA). CASE: A 27-year-old man presented with a firm, midline, perineal mass. Magnetic resonance imaging showed a 3-cm, enhancing mass that was considered neoplastic. FNA biopsy, followed by cytologic examination, revealed moderately cellular aspirates composed of discohesive, small, blue cells with scant cytoplasm, high nuclear/cytoplasmic ratios and pleomorphic nuclei with irregular nuclear contours; uniform, hyperchromatic chromatin; and occasional mitotic figures. Frequent naked nuclei and scattered cells with more abundant, dense cytoplasm and eccentric nuclei were also noted. The diagnosis of rhabdomyosarcoma was favored on FNA and was corroborated by immunohistochemical stains for desmin, myogenin and CD56. Upon surgical resection, the diagnosis of alveolar rhabdomyosarcoma was confirmed histologically and immunophenotypically. CONCLUSION: FNA is a useful tool in diagnosing soft tissue lessions of the perineum, including rare primary tumors, such as adult rhabdomyosarcoma. In this case, early identification avoided incisional biopsy and directed appropriate extirpative surgery and reconstruction considerations.     

Lymphoepithelial cyst with crystalloid formation. Cytologic features of two cases

BACKGROUND: The presence of amylase crystalloids (AC) in cystic lesions of the parotid gland is a rare occurrence and has been diagnosed to date as sialadenitis. We report the first two cases of parotid lymphoepithelial cyst (LC) containing this type of crystalloid. CASES: Case 1, a 56-year-old male, presented with a 3-cm parotid cyst. Fine needle aspiration (FNA) was performed on the mass. Smears showed numerous crystalloids identical to those described as crystallized amylase. Case 2, a 36-year-old female, had a 2-cm parotid mass. FNA smears exhibited the same features as did case 1. The two patients were treated with superficial parotidectomy, and an LC containing AC was diagnosed in both cases. CONCLUSION: When the above findings are present on FNA of parotid gland, the diagnosis of LC must be considered.     

Pleomorphic adenoma of salivary gland: to what extent does fine needle aspiration cytology reflect histopathological features?

OBJECTIVE: The histological diversity encountered in pleomorphic adenoma may cause diagnostic difficulty in fine needle aspiration (FNA) cytology due to limited and selective sampling. The present study based on 25 histologically confirmed pleomorphic adenoma cases attempts to find out to what extent FNA cytology reflects the histopathological features. METHODS: May-Grunwald-Giemsa and Papanicolaou stained smears, and haematoxylin and eosin stained paraffin sections of 25 pleomorphic adenomas of parotid and submandibular glands were reviewed. The cellularity, which was assessed in a sliding scale of 1+ to 4+, and proportions of epithelial to mesenchymal components in FNA smears and histology was determined and compared. The frequency of morphological features such as squamous metaplastic cells, cells with oncocytic change, acinus formation, mucus globules, papilla formation, giant cells, myxoid and chondroid matrix as well as specific nuclear features was compared between the two diagnostic methods, and the statistical significance was determined using Fisher's exact test of probability. RESULTS: There was complete concordance between cytology and histology with respect to overall cellularity in 14 (56.0%) cases and in the proportions of epithelial to mesenchymal components in 13 (52.0%). Epithelial cells and myxoid matrix were present in all cases. There was no significant difference between smear and tissue section with respect to frequency of squamous metaplasia, oncocytic change, acinus formation, papilla formation, mucus globules, giant cells, nuclear pleomorphism, nuclear chromatin pattern, and mitotic figures. Morphological parameters that were significantly higher in FNAC compared with histology included intranuclear cytoplasmic inclusions (36.0% versus 8.0%, p = 0.0374), nuclear grooves (84.0% versus 48.0%, p = 0.0090), and reniform nuclei (20.0% versus 0.0%, p = 0.0502). Chondroid matrix was the only parameter which was significantly more common in histology than in cytology (44.0% versus 4.0%, p = 0.019). CONCLUSION: FNA cytology demonstrates well most of the histological features of pleomorphic adenoma of salivary gland and may be considered a useful tool in initial assessment of the tumour.     

Schwannomalike mixed tumor of the parotid gland: a case report

BACKGROUND: Schwannomalike mixed tumor is a rare benign tumor of the parotid glands. CASE: A 75-year-old woman presented with a tumor 3 cm in diameter localized in her left parotid gland. Fine needle aspiration (FNA) of the lesion revealed 2 types of cells: 1 with elongated, wavy, hyperchromatic nuclei and a scant cytoplasmic border and 1 with larger, weakly staining nuclei and more abundant cytoplasm. Morphologic examinations were performed. CONCLUSION: FNA cytology was very useful in the diagnosis of this rare tumor of the parotid gland.