Two cytologic patterns in invasive ductal adenocarcinoma of the pancreas

OBJECTIVE: To clarify 2 cytologic patterns: severe ductal dysplasia (SD)/carcinoma in situ (CIS) and invasive components of invasive ductal adenocarcinoma of the pancreas (IDAP). STUDY DESIGN: Tumor samples from 12 patients with IDAP were examined cytologically and histologically. Cytologic specimens were obtained by fine needle aspiration (ENA) and imprint smears from resected pancreases. RESULTS: In the 12 IDAP cases, roughly 2 cell populations, SD/CIS-type cells and invasive component-type cells, were detected cytologically. The former composed a small portion of the tumor cells, exhibited a small nuclei without anisonucleosis and had a decreased total quantity of chromatin as compared with invasive component-type cells. SD/CIS-type cells were found in small papillary-cohesive and compactly packed clusters and had clearly defined cytoplasmic borders, a nucleus individually enveloped in well-preserved cytoplasm and small amount of cytoplasm (< 15 microm in short diameter) without prominent anisocytosis. The latter comprised mostly of the tumor cells, were present characteristically as a loose and discohesive population and contained a combination of hyperchromatin, large nuclei (> 15 microm) and abundant cytoplasm (>21 microm). Histologically, these 12 cases exhibited IDAP with SD/CIS. Hence, the invasive component-type cells appeared to originate with ordinary invasive spread of IDAP, and the SD/CIS type cells appeared to originate with noninvasive intraductal spread. CONCLUSION: Two cytologic patterns originating with SD/CIS and invasive components of IDAP could be differentiated.     

Psammoma bodies in fine needle aspirates from thyroids containing nontoxic hyperplastic nodular goiters

Psammoma bodies present in fine needle aspiration (FNA) smears with typical cytologic features of colloid goiter from five patients raised the possibility of coexistent papillary carcinoma. However, subsequent careful histologic examination of the entire thyroidectomy specimens did not show occult carcinoma in any of the cases. The psammoma bodies were identified in the stroma next to the foci of papillary hyperplasia in each case. They were small, often equal in size to or slightly larger than the follicular epithelial cell nuclei, and could be misinterpreted as epithelial cell nuclei. These findings suggest that the presence of psammoma bodies in an FNA smear cytologically consistent with a colloid goiter should raise the possibility of coexistent papillary hyperplasia or neoplasia. However, because of the strong statistical association of psammoma bodies with malignant thyroid neoplasms, histologic confirmation is mandatory in such cases.     

Cystosarcoma phyllodes. Diagnosis by fine needle aspiration cytology.

The cytologic features of 10 benign, 2 borderline and 5 malignant phyllodes tumors were studied, and an attempt was made to correlate the cytologic findings with corresponding histologic categories. Seventy-five percent of the benign and borderline tumors were interpreted as benign cystosarcoma phyllodes on fine needle aspiration cytology. Eighty percent of the malignant phyllodes tumors were identified as malignant lesions cytologically. The cytologic features assessed were the epithelial:stromal ratio and morphology of the stromal component, including the degree of atypia, mitotic activity, capillary vessels traversing the stromal fragments, presence of foamy macrophages, histiocytic giant cells and bipolar naked nuclei. A diagnosis of phyllodes tumor was suggested cytologically by the presence of both epithelial and stromal elements; the stroma was present as cellular "phyllodes fragments" and isolated mesenchymal cells. The parameters suggesting malignancy were extreme paucity or absence of epithelial elements and stromal cells in diffuse sheets and clusters less cohesive than normal, with marked stromal atypia and mitotic activity.     

Criteria for the diagnosis of fibroepithelial lesions of the breast with liquid-based cytology

OBJECTIVE: To establish diagnostic criteria for diagnosing and differentiating fibroepithelial lesions of the breast on ThinPrep (Cytyc Corp., Boxborough, Massachusetts, U.S.A.). STUDY DESIGN: Eighty-four fibroepithelial lesions were sampled by ultrasound-guided aspiration biopsy. Based on smears and histologic correlates, there were 55 fibroadenomas, 26 papillary neoplasms and 3 phyllodes tumors. The ThinPrep slides for each sample were reviewed retrospectively and evaluated for specific morphologic and cytologic features. RESULTS: On ThinPrep slides, 95% of the fibroadenomas had a predominance of single myoepithelial nuclei, 89% had staghorn clusters, and 47% had myxoid stroma. Among the papillary neoplasms, 8% had a predominance of single columnar ductal cells, 31% had papillary groups, 23% had vessels, and 27% had collagenous spherulosis. The ThinPrep preparations of the phyllodes tumors showed that 67% had single myoepithelial nuclei, 33% had a predominance of single ductal cells, 67% had staghorn clusters, and 0% had myxoid stroma. A majority of the fibroadenomas and the papillary neoplasms showed mild to moderate ductal epithelial hyperplasia. A majority of the phyllodes tumors showed moderate ductal epithelial hyperplasia. CONCLUSION: Fibroepithelial lesions of the breast can be accurately differentiated using ThinPrep samples based on the evaluation of specific cytologic and morphologic features, including the presence of staghorn clusters, fibromyxoid stroma, vessels, collagenous spherulosis, papillary clusters and predominance of myoepithelial nuclei or columnar cells in the background. However, the degree of ductal epithelial hyperplasia does not aid in the diagnosis.     

Fine needle aspiration cytology of invasive micropapillary carcinoma of the breast. A case report

BACKGROUND: Invasive micropapillary carcinoma of the breast is uncommon and was characterized only recently. Awareness of this entity and its cytologic appearance is important to allow early diagnosis by fine needle aspiration cytology (FNAC). To our knowledge, only two cases of FNAC of this lesion have been reported in the English-language literature. CASE: An 80-year-old female presented with a firm, nontender mass in the upper outer quadrant of the left breast. FNAC showed ductal carcinoma, and mastectomy showed invasive micropapillary carcinoma. The patient had axillary metastases and received tamoxifen. CONCLUSION: The cytologic features of invasive micropapillary carcinoma are distinctive, with clusters of cells showing hyperchromatic, irregular and crowded nuclei and peripherally located cytoplasm with a rare central lumen. Fibrovascular cores are absent. Although FNAC experience with this lesion is limited, the characteristic cytologic features, including "inside-out" cell clusters, should raise the suspicion of this variant of ductal carcinoma. Differentiation from other papillary lesions and malignancies may be possible, but more experience is needed as the number of reported cases remains limited.     

Cytologic diagnosis of alveolar soft part sarcoma of the lower extremity by fine needle aspiration and correlation with core biopsy: a case report

BACKGROUND: Alveolar soft part sarcoma is a rare soft tissue tumor of uncertain origin that is generally slow growing but unmistakably malignant due to its propensity for metastasis to lung, bone and brain early in the course of disease. Fine needle aspiration biopsy (FNAB) of these tumors and recognition of the characteristic cytologic features precludes more invasive diagnostic measures and facilitates appropriate treatment. CASE: A 54-year-old African-American man presented to our institution with a 2-week history of left leg pain. Imaging studies revealed a left leg soft tissue mass just below the popliteal fossa and multiple bilateral lung lesions suggestive of metastatic neoplasm. FNAB of the left lower extremity mass yielded uniform clusters of cells and sigle cells with large nuclei and single prominent nucleoli. Histologically, the biopsy showed nests of large polygonal cells with abundant eosinophilic cytoplasm, round regular nuclei and prominent nucleoli. A periodic acid-Schiff (PAS) stain highlighted intracytoplasmic rhomboidal crystals, a feature diagnostic of alveolar soft part sarcoma. CONCLUSION: Alveolar soft part sarcoma may be diagnosed by its unique morphologic characteristics and should be considered in the differential diagnosis of all cytologically sampled soft tissue lesions.     

Fine needle aspiration cytology of invasive micropapillary (pseudopapillary) carcinoma of the breast. Report of 11 cases with clinicopathologic findings

OBJECTIVE: To describe the cytologic features of invasive micropapillary carcinoma of the breast, a distinct, unusual variant of infiltrating duct carcinoma characterized histologically by pseudopapillary structures lacking fibrovascular cores and tubuloalveolar structures floating freely within clear spaces separated by a delicate fibrocollagenous stroma and characterized clinically by prominent lymphotropism and an aggressive clinical course. STUDY DESIGN: We reviewed the clinical, cytologic, histologic, immunohistochemical and flow cytometric features in 11 cases of invasive micropapillary carcinoma of the breast diagnosed preoperatively by fine needle aspiration. RESULTS: All patients were women, ranging in age from 31 to 83 years. A preoperative diagnosis of malignancy was made in all cases. Tumor size ranged from 1.2 to 5.5 cm. Ten patients had lymph node metastases. Cytology was characterized by a "dual" pattern formed by round or angulated, three-dimensional, cohesive clusters of neoplastic cells with pseudopapillary configuration and two-dimensional, dyscohesive aggregates and single cells with high grade nuclei and intact cytoplasm.     

Papillary carcinoma of the breast. Cytologic study of nine cases.

OBJECTIVE: To study the cytologic findings of papillary breast carcinoma by fine needle aspiration. STUDY DESIGN: The study group consisted of fine needle aspiration (FNA) specimens of breast tumors from nine patients performed during the period 1988-1997. Eight were female, and one was male. The FNA results were compared with the final histologic diagnosis. RESULTS: The tumor sizes were 4-6.5 cm. The aspirations yielded a good amount of bloody material. The smears revealed high cellularity, papillary clusters, isolated low-to-tall columnar cells, mild to moderate atypia, hemorrhagic background, foam and hemosiderin-laden macrophages, calcification, rare mitoses, palisading row of cells and bipolar cytoplasmic eosinophilic granules. The smears were diagnosed as either suspicious or suggestive of papillary carcinoma. The histologic examination revealed invasive papillary carcinoma. CONCLUSION: Papillary carcinoma of the breast can be diagnosed by using a panel of cytologic findings that includes hypercellularity, papillary clusters, hemorrhagic background, palisading rows of tall columnar cells, cellular atypia and calcification. The interesting finding in this study was the presence of eosinophilic bipolar cytoplasmic granules, which has not been reported before.     

Clinical and cytologic features of papillary neoplasms of the breast

OBJECTIVE: To compare the cytologic features benign and malignant papillary breast lesions. STUDY DESIGN: We reviewed the clinical and cytologic features in 29 cases of intraductal papilloma and 26 cases of atypical papilloma or papillary carcinoma that had been diagnosed by histologic examination. The diameter of the mass was examined as a clinical feature. The cytologic features evaluated were as follows: bloody background, row of tall columnar cells, naked bipolar nuclei, hemosiderin-laden macrophages, myoepithelial cells, single scattered atypical cells, cellularity, nuclear atypia, nuclear grade, apocrine metaplasia, eosinophilic cytoplasmic granules, papillary clusters, small papillae, cell balls and large sheets. RESULTS: Of the features evaluated, the diameter of the mass, naked bipolar nuclei and cell balls differed significantly between benign and atypical or malignant papillary neoplasms. The average diameter of a benign papillary neoplasm was 1.8 cm, and that of an atypical or malignant papillary neoplasm was 2.2 cm (p = 0.042). Naked bipolar nuclei were found in 27 cases of benign papillary neoplasm (93.1%) versus 19 cases of atypical or malignant papillary neoplasm (73.1%) (p = 0.050). Cell balls were found in 14 (48.3%) and 21 (80.8%) cases, respectively (p = 0.012). All 6 cases in which cell balls were present and naked bipolar nuclei were absent proved to be atypical or malignant papillary neoplasms. Of 17 cases in which cell balls were absent and naked bipolar nuclei present, 13 (76.5%) were benign papillary neoplasms. CONCLUSION: Most cytologic features overlapped in benign and atypical or malignant papillary neoplasms. Although they were not pathognomonic, naked bipolar nuclei and cell balls were cytologic features that differed significantly between benign and atypical or malignant papillary neoplasms. When papillary neoplasms of the breast are suspected in a cytologic smear, the combination of clinical examination, mammography and cytologic features should be considered to make the correct diagnosis.     

Cytologic features of ovarian tumors of low malignant potential in peritoneal fluids

The distinction of ovarian tumors of low malignant potential (OTLMP) from invasive ovarian carcinomas has significant therapeutic and prognostic implications. This study was undertaken to define the cytologic features of OTLMP in peritoneal fluids and to compare them with the cytologic features of invasive carcinomas. Peritoneal fluids from 13 patients with OTLMP and 10 patients with invasive ovarian carcinoma contained neoplastic cells and were reviewed with attention to papillary fragment morphology, cellular pleomorphism and cytoplasmic and nuclear characteristics. Cytologic preparations from patients with OTLMP contained large, cohesive papillary fragments with smooth borders. The neoplastic cells were relatively small and uniform, with high nuclear-cytoplasmic (N/C) ratios (greater than 1:2), few intracytoplasmic vacuoles and inconspicuous nucleoli. Mitotic figures were rare. Peritoneal fluids from patients with invasive ovarian carcinoma contained smaller discohesive papillary fragments with irregular borders. The neoplastic cells were relatively large and pleomorphic, with low N/C ratios (less than or equal to 1:2), abundant intracytoplasmic vacuoles and prominent nucleoli; most preparations contained many single cells and mitotic figures.     

Fine needle aspiration cytologic findings in metastatic basaloid squamous cell carcinoma of the head and neck.

Basaloid squamous cell carcinoma of the head and neck is a variant of squamous carcinoma the cytomorphology of which has not been examined previously. The cytologic features of metastatic basaloid squamous cell carcinoma in fine needle aspiration specimens from nine patients are described. The primary tumors, when known, were located in the base of the tongue, tonsil, epiglottis, nasopharynx, hypopharynx and false vocal cord. Each neoplasm had large fragments or clusters of crowded cells and scattered single cells in the cytologic smears. The cells had round or oval, hyperchromatic nuclei that often had single, small nucleoli. The nuclei usually were small or medium sized, but six tumors had a few cells the nuclei of which were large and pleomorphic. The cytoplasm was typically scant, and only three cases had occasional keratinized cells. Necrosis was present in six neoplasms. Three neoplasms, originally diagnosed as small cell undifferentiated carcinoma, contained numerous single cells and small clusters of cells with nuclear molding. On review, however, smears from these neoplasms also contained a few large fragments of tightly cohesive cells with larger, vesicular nuclei. Another basaloid squamous cell carcinoma had been interpreted elsewhere as an adenoid cystic carcinoma because of the presence of pseudoglandular structures with stromal cores. Although the cytologic features of basaloid squamous cell carcinoma may mimic those of other poorly differentiated carcinomas in fine needle aspiration specimens, they are sufficiently distinctive that a diagnosis of this variant of squamous cell carcinoma can be suggested for a patient whose primary neoplasm is located in the upper aerodigestive tract.     

Morphometric image analysis of follicular lesions of the thyroid

OBJECTIVE: To determine the role of image morphometry in distinguishing various follicular lesions of the thyroid in cytologic smears. STUDY DESIGN: Archival fine needle aspiration smears of 10 cases each of follicular hyperplasia, follicular adenoma, follicular carcinoma and follicular variant of papillary carcinoma were used for the study. All cases were histopathologically proven. At least 100 random nuclei from each case were subjected to analysis with an image cytometer. Area, convex area, length, width, perimeter, convex perimeter and roundness of nuclei were measured using a 40 x objective (1 pixel = 0.446 micron). RESULTS: ANOVA showed that all the nuclear variables studied were significantly different (P < .05) in follicular hyperplasia as compared to follicular carcinoma and papillary carcinoma. All nuclear variables except roundness were also significantly different (P < .05) between follicular hyperplasia and follicular adenoma. However, between follicular adenoma, follicular carcinoma and papillary carcinoma there was considerable overlap of nuclear morphometric parameters. CONCLUSION: Image morphometry may help to distinguish nonneoplastic follicular lesions (hyperplasia) from neoplastic lesions (adenomas and carcinomas). However, to distinguish benign from malignant follicular lesions, image morphometry might not improve the accuracy of standard cytologic examination.     

Thyroid metastasis from intraductal papillary-mucinous carcinoma of the pancreas. A case report

BACKGROUND: Intraductal papillary-mucinous carcinoma (IPMC) of the pancreas is a newly identified clinicopathologic entity of the exocrine pancreas. It has been considered a slowly growing and less-aggressive carcinoma with a favorable prognosis. There have been only a few documents reporting its distant metastasis and cytologic features, with no report of thyroid metastasis until the present. CASE: A case of IPMC occurred in a 45-year-old male, who was admitted with rapid growth and tenderness of the thyroid. Abdominal computed tomography showed the typical cystic dilatation of IPMC with adjacent organ metastasis. Fine needle aspiration of the thyroid yielded papillary fronds of carcinoma cells with nuclear pleomorphism, abundant cytoplasm and prominent nucleoli in a mucinous background. Immunohistochemical findings from the skin and thyroid characterized the papillary-mucinous carcinoma as having originated in the pancreas. CONCLUSION: This case suggests that papillary carcinoma fronds aspirated from the thyroid should be further differentiated from the primary site and that a pleomorphic nucleus in a mucinous background is a useful feature to exclude a thyroid origin. Before this, distant metastasis of IPMC to the skin and thyroid has not been reported. The prognosis of IPMC with wide, distant metastasis at an advanced stage is poor.     

Fine needle aspiration cytology of invasive cribriform carcinoma of the breast with osteoclastlike giant cells: a case report

BACKGROUND: Nonneoplastic osteoclastlike giant cells are occasionally associated with carcinoma of the breast, pancreatobiliary and gastrointestinal systems. In the breast, this uncommon stromal response is seen mainly in invasive carcinoma with low grade cytology, among which invasive cribriform carcinoma is the classic example. Details of the fine needle aspiration cytology of this phenomenon, especially in thin-layer preparations, have been described rarely. CASE: The fine needle aspiration cytology of an invasive cribriform carcinoma of the breast occurred in a 66-year-old woman. Cytology showed cohesive sheets and three-dimensional cribriform clusters of bland-looking and mitotically inactive ductal cells in a blood-stained background. Scattered multinucleated, osteoclastlike giant cells, some containing hemosiderin granules, were also seen. Myoepithelial cells and naked nuclei were not obvious. The cellular composition was more discernible in liquid-based cytologic preparations. Histologic examination of the excisional biopsy showed an invasive cribriform carcinoma associated with many osteoclastlike giant cells in a hypervascular stroma. CONCLUSION: In view of the extremely low grade cytology of the malignant ductal cells, invasive cribriform carcinoma may closely mimic benign proliferative breast diseases on fine needle aspiration biopsy. Recognition of this special relationship with osteoclastlike giant cells, which are rarely present in certain subtypes of breast cancer but not benign lesions, can help to arrive at a correct cytologic diagnosis.     

Aspiration cytology of the oncocytic variant of papillary adenocarcinoma of the thyroid gland

OBJECTIVE: To study the cytologic features of the oncocytic variant of papillary adenocarcinoma of the thyroid gland to distinguish this subtype from other oncocytic lesions of the thyroid. STUDY DESIGN: We reviewed the smears from aspiration biopsies of 6 proven cases of oncocytic variant of papillary adenocarcinoma and compared their cytologic features with smears from 19 oncocytic follicular neoplasms (11 adenocarcinomas and 8 adenomas). Smears were stained with a modified Giemsa stain (Diff-Quik). RESULTS: All smears were cellular. Colloid was variable but more abundant in cases of the oncocytic variant of papillary adenocarcinoma. The cells in papillary adenocarcinoma had round to ovoid, overlapped nuclei; prominent intranuclear inclusions; and "grooves." Nucleoli were generally absent. In oncocytic follicular neoplasms, the cells had round nuclei and prominent nucleoli. Nuclear inclusions and grooves were seen but were not as prevalent as in papillary adenocarcinomas. CONCLUSION: The oncocytic variant of papillary adenocarcinoma of the thyroid gland can be distinguished from other oncocytic lesions by fine needle aspiration biopsy, whereas the absence of prominent nucleoli in oncocytes favors the diagnosis of an oncocytic papillary adenocarcinoma.     

Papillary neoplasms of the breast: clues in fine needle aspiration cytology

Papillary neoplasms of the breast include a wide spectrum of mammary lesions. The differential diagnosis of benign and malignant lesions can be problematic not only cytologically, but also histopathologically. Aspiration smears can demonstrate that cytological differentiation is feasible. A retrospective study of 30 cases of papillary tumour of the breast, 15 papillary carcinomas and 15 papillomas, was performed to find the cytological differences between the pathologies. Cytological samples of papillary carcinomas were characterized by an abundance of cellular material, three-dimensional papillary clusters without fibrovascular connective tissue cores, small papillae arranged in cell balls, tall columnar cells and isolated naked nuclei. Numerous haemosiderin-laden macrophages were seen. There were no eosinophilic bipolar cytoplasmic granules, bipolar naked nuclei or apocrine metaplasia. In the papillomas there was less material; the papillae had cohesive stalks surrounded by columnar cells in a honeycomb pattern. We also found fewer small papillae and isolated columnar cells. In addition, the presence of apocrine metaplasia and bipolar naked nuclei was noted. We suggest that papillary carcinoma of the breast can be diagnosed by cytology and differentiated from papilloma.     

Cytologic appearances in invasive lobular carcinoma of the breast. A study of 21 cases

OBJECTIVE: To examine the fine needle aspiration cytologic features of invasive lobular carcinoma of breast and to discuss problems that may occur in cytodiagnosis. STUDY DESIGN: Fine needle aspiration cytologic smears from 21 cases of invasive lobular carcinoma (ILC) of breast were subjected to detailed cytomorphologic analysis. Features studied included pattern of cells, size of cells, nuclear placement, pleomorphism, presence of intracytoplasmic lumina (ICL) and signet ring cells. RESULTS: Cellularity was generally moderate or high, and the pattern was predominantly or partly dissociated in 86% of cases. Rosettelike pattern was discerned in alveolar-type ILC. Cell size was usually small or intermediate, with nuclei placed eccentrically in most cases. ICLs with or without signet ring cells were present in 12 cases (57%). CONCLUSION: A cytologic picture consisting of predominantly dissociated small or intermediate-sized tumor cells with eccentric nuclei, with some of the cells showing ICLs, is highly suggestive of ILC. Indian file pattern, another characteristic feature of ILC, is, however, focal and inconsistent. Variant patterns of ILC may show other cytologic features, such as rosettelike pattern (alveolar variant of ILC) or large cell pattern (pleomorphic variant of ILC) and may consequently be difficult to categorize on cytologic smears.     

Fine needle aspiration cytology of primary pulmonary paraganglioma. A case report

BACKGROUND: Primary pulmonary paragangliomas are rare tumors. To our knowledge, there is no prior report on fine needle aspiration cytology (FNAC) in pulmonary paraganglioma. CASE: A 34-year-old man presented with an incidentally found solitary pulmonary mass. FNAC showed papillarylike clusters of epithelioid cells with round to oval nuclei, evenly dispersed chromatin, micronucleoli and occasional anisonucleosis. These cytologic features were suggestive of a sclerosing hemangioma or bronchioloalveolar carcinoma. A right lower lobectomy revealed a primary pulmonary paraganglioma. CONCLUSION: The possibility of pulmonary paraganglioma should be considered in the differential diagnosis of FNAC showing pseudopapillary clusters of epithelioid cells.     

Intraductal papilloma of the salivary gland. A report of two cases with diagnosis by fine needle aspiration biopsy

BACKGROUND: Intraductal papillomas are rare, benign tumors most commonly encountered in minor salivary glands. They are cystic, solitary neoplasms that arise from ductal epithelium and produce painless swellings. CASES: Two cases arose in major salivary glands. The first case was a superficial, firm mass at the superior edge of the parotid, cytologically evocative of an adnexal tumor. A firm, submandibular mass in the second case was diagnosed as a papillary neoplasm. Fluid was aspirated from both cases. Three-dimensional epithelial clusters, some with a papillary configuration and histiocytes, were the main cellular components. The majority of cells showed oncocytic differentiation; however, benign-appearing ductal cells in honeycomb sheets were also present. The first case also had occasional cells suggestive of sebaceous differentiation. The excised lesions were unilocular cystic papillary neoplasms consistent with intraductal papilloma; focal sebaceous differentiation was noted in the first case. CONCLUSION: Awareness of the cytologic features of intraductal papilloma of the salivary glands should prompt its inclusion in the differential diagnosis of papillary lesions of the head and neck.     

Polymorphous low grade adenocarcinoma of the salivary gland. Diagnosis by fine needle aspiration cytology

OBJECTIVE: To describe the fine needle aspiration cytology findings of polymorphous low grade adenocarcinoma of the salivary gland. STUDY DESIGN: The authors reviewed the cytologic findings of 5 cases of polymorphous low grade adenocarcinoma. All cases were confirmed by histologic examination. RESULTS: All cases showed similar cytologic findings. The smears had high cellularity with a population of mixed epithelial and myoepithelial cells. These cells formed branching papillae, sheets and clusters. The epithelial cells were uniform, with round to ovoid nuclei; absent or inconspicuous nucleoli; and a moderate amount of dense cytoplasm. Occasionally the cells formed spherical structures containing hyaline globules. Myxoid matrix, either dispersed in the background or interspersed with the cellular elements, was also seen often. CONCLUSION: Polymorphous low grade adenocarcinoma should be cytologically differentiated from adenoid cystic carcinoma, monomorphic adenoma and pleomorphic adenoma. Recognition of subtle cytologic features. may be useful in the differential diagnosis.