Salivary duct carcinoma (SDC), which was described first by Kleinsasser

Transcription

1 344 CANCER CYTOPATHOLOGY Salivary Duct Carcinoma Cytologic Characteristics and Application of Androgen Receptor Immunostaining for Diagnosis Toshiaki Moriki, M.D. Shousuke Ueta, C.T. Tamotsu Takahashi, C.T. Miko Mitani, C.T. Miho Ichien, M.T. Department of Clinical Laboratory, Kochi Medical School Hospital, Nankoku, Kochi, Japan. BACKGROUND. Although there have been several reports of cytologic features for salivary duct carcinoma (SDC), it still can be difficult to diagnose patients with these tumor accurately at the time of fine-needle aspiration (FNA). Review of the literature indicates that, immunohistochemically, SDC expresses androgen receptor (AR) in the majority of patients. The authors investigated the cytologic characteristics and utility of AR immunostaining on cytologic smears for the diagnosis of patients with SDC. METHODS. FNA and imprint smears from four patients with SDC were stained with Papanicolaou and periodic acid-schiff (PAS). Immunostaining for AR on paraffin sections and imprint smears of SDC was performed, including 51 benign and other malignant salivary gland tumors. RESULTS. The smears were cellular and contained three-dimensional clusters, flat sheets, and scattered epithelial cells with necrotic backgrounds. A cribriform architectural pattern was noted in many of the tumor sheets. The tumor cells were large polygonal, spindle, and round to oval, and had abundant, finely granular, or vacuolated cytoplasm. Intracytoplasmic vacuoles were PAS negative. The nuclei were hyperchromatic, medium to large in size, round to oval in shape, and often had prominent nucleoli. All SDC tumors expressed AR. Two patients with carcinoma in (pleomorphic adenoma) showed a focal, comedo carcinoma pattern in which AR positive nuclei were observed. Other salivary gland tumors were completely negative for AR. CONCLUSIONS. The cytologic features of high-grade adenocarcinoma with a variety of cell morphologies, flat sheets of tumor cells with a cribriform pattern, and necrotic backgrounds are characteristic findings in patients with SDC. Immunostaining for AR on cytologic smears is useful for the diagnosis of these patients. Cancer (Cancer Cytopathol) 2001;93: American Cancer Society. Address for reprints: Toshiaki Moriki, M.D., Department of Clinical Laboratory, Kochi Medical School Hospital, Nankoku, Kochi Japan; Fax: ; morikit@med. kochi-ms.ac.jp. Received March 1, 2001; revision received June 5, 2001; accepted June 21, KEYWORDS: salivary duct carcinoma, cytology, immunohistochemistry, androgen receptor. Salivary duct carcinoma (SDC), which was described first by Kleinsasser et al. 1 in 1968, is an uncommon salivary gland tumor with a histologic resemblance to ductal carcinoma of the breast. Comedo necrosis is a common feature. 2 6 SDC occurs in the major salivary glands, particularly the parotid gland. 2 Most patients are males and are age 50 years. SDC frequently has an aggressive clinical behavior, with invasion of the facial nerve, local recurrence, and/or distant metastasis. 2 Aggressive clinical management, including radical surgery and postoperative radiation therapy in the early stage of the tumor, appears to be the only hope for long-term survival. 2,7 Therefore, establishing an accurate preoperative diagnosis by fine-needle aspiration (FNA) is important. Although there have been several re American Cancer Society

2 Cytology and AR of Salivary Duct Carcinoma/Moriki et al. 345 TABLE 1 Clinicopathologic Findings in Six Patients with Salivary Duct Carcinoma Characteristic Patient 1 Patient 2 Patient 3 Patient 4 Patient 5 Patient 6 Age (yrs) Gender Male Male Male Male Male Male Symptoms ; facial nerve palsy ; facial nerve palsy Site Right parotid Right parotid Left parotid Right parotid Left submandible Right parotid Tumor size (cm) TNM classification a T4bN2bM0 stage IV T2aN0M0 stage I T3bN0M0 stage III T2bN2bM0, Stage IV T2bN2bM0, Stage IV T4bN2bM0, Stage IV Follow-up Local recurrence and metastasis in lung and brain; died of disease at 2 yrs Alive with disease at 4.5 yrs; metastasis in lung and brain No evidence of disease at 6 months Metastasis in lung; died of disease at 2 yrs 1 yr later, lost to follow-up Uncontrollable local disease; died of disease at 6 months a See Hermanek et al., ports of cytologic features for SDC, 8 17 it still may be difficult to diagnose the tumor accurately at the time of FNA. In addition to thorough FNA sampling of different areas of the tumor, clinical findings may be useful in suggesting the correct diagnosis. 13 Review of the literature indicates that, immunohistochemically, SDC expresses androgen receptor (AR) in the majority of patients. 18,19 This study was undertaken to evaluate the cytologic features of SDC to define better the diagnostic characteristics of SDC and to investigate the significance of AR immunostaining for the diagnosis of SDC. MATERIALS AND METHODS Six histologically confirmed patients with SDC were studied. FNA and imprint cytology were performed in four patients (Patients 1 4 in Table 1). The smears were fixed in 95% ethanol and stained by the standard Papanicolaou method and periodic acid-schiff (PAS). For histopathologic study, the surgical materials from six patients were fixed in 20% neutral buffered formalin, embedded in paraffin, sectioned at 4- intervals, and stained with hematoxylin and eosin and PAS. Slides were reviewed critically to ensure adherence to strict diagnostic criteria for SDC. 2,4 The clinicopathologic findings in these patients are summarized in Table 1. Immunohistochemical staining for AR (1:70 dilution; mouse monoclonal; BioGenex, San Ramon, CA) was carried out with an automated immunostaining system (OptiMax Plus; BioGenex) on 4- paraffin sections from each patient and on ethanol fixed imprint smears from three patients employing a biotinstreptavidin amplified method. Diaminobenzidine was used as a chromogen, and sections and/or smears were counterstained lightly with hematoxylin. Positive tissue and/or smear control samples of breast carcinoma as well as negative control slides that were run simultaneously were used to assess the quality of immunostaining. On paraffin sections, microwave pretreatment for antigen retrieval was carried out prior to incubation with primary antibody. Microwave pretreatment was omitted on imprint smears. In addition, we examined AR expression in 21 samples of benign salivary glands and in 30 samples of other malignant salivary gland tumors. Immunohistochemical studies of estrogen receptor (ER; prediluted; mouse monoclonal ER88; BioGenex) and progesterone receptor (PgR; prediluted; mouse monoclonal PR88; BioGenex) also were performed on paraffin sections from the six patients with SDC using the same method. RESULTS Cytologic Findings For two patients, the initial FNA cytologic diagnoses of SDC were high-grade adenocarcinomas (Patients 1 and 3). The FNA specimens from two patients and the imprint smears from three patients were cellular and consisted of cohesive, three-dimensional clusters and flat sheets of tumor cells with necrotic backgrounds (Fig. 1). A cribriform architectural pattern was noted in many of the tumor sheets (Fig. 2). At the periphery of these sheets, there were many scattered, individual tumor cells. The tumor cells were large, polygonal, spindle, and round to oval and had abundant, finely granular, or vacuolated cytoplasm. The nuclei were

3 346 CANCER (CANCER CYTOPATHOLOGY) October 25, 2001 / Volume 93 / Number 5 FIGURE 1. A fine-needle aspiration biopsy specimen from Patient 1 shows a cluster of three-dimensional tumor cells with a necrotic background (Papanicolaou stain; original magnification, 200). FIGURE 3. A fine-needle aspiration biopsy specimen from Patient 3 shows highly pleomorphic tumor cells with abundant, finely granular, and vacuolated cytoplasm. Enlarged, round nuclei with prominent nucleoli and mitotic figures are seen (Papanicolaou stain; original magnification, 400). FIGURE 2. A fine-needle aspiration biopsy specimen from Patient 3 shows a sheet of cells with a cribriform pattern (Papanicolaou stain; original magnification, 200). FIGURE 4. An imprint smear from Patient 4 shows scattered, large tumor cells with round-to-oval, hyperchromatic nuclei (Papanicolaou stain; original magnification, 400). hyperchromatic, medium to large in size, round to oval in shape, and often had prominent nucleoli (Figs. 3, 4). Cytoplasmic vacuoles were stained negatively with PAS. Mitotic figures were observed frequently. The cytologic findings are summarized in Table 2. Pathologic Findings The tumors ranged in size from 2.5 cm to 10.0 cm. The margins were infiltrative macroscopically. The cut surfaces were yellow-gray and contained necrotic and cystic areas. Microscopically, the tumors were comprised of well-defined islands of epithelial cells exhibiting a cribriform pattern and central comedo necrosis, strongly resembling ductal carcinoma of the breast (Fig. 5). The tumor cells had round-to-oval nuclei with prominent nucleoli and abundant, eosinophilic, granular, or vacuolated cytoplasm. Intracytoplasmic vacuoles were negative with PAS. Mitotic figures were observed frequently. Immunohistochemical Study Immunostainings for AR, ER, and PgR were successful on positive and negative control slides. The results of immunohistochemical study are listed in Table 3. In five of the six SDC samples, strong immunostaining for AR was observed diffusely in the nuclei of neoplastic cells (Fig. 6). Almost 100% of the tumor cells were positive. The single remaining sample (Patient 1) was weakly stained in about 50% of neoplastic cell nuclei. AR was not expressed in the adjacent normal salivary glands. Two of the three patients with carcinoma in pleomorphic adenoma showed a focal, comedo carci-

4 Cytology and AR of Salivary Duct Carcinoma/Moriki et al. 347 TABLE 2 Cytologic Features of Four Patients with Salivary Duct Carcinoma Sample characteristic Patient 1 (FNAC) Patient 2 (imprint) Patient 3 (FNAC, imprint) Patient 4 (imprint) Background Extensively necrotic Necrotic Necrotic Extensively necrotic Cell Arrangement Stratification, sheets, cribriform Sheets, cribriform, scattered Stratification, sheets, cribriform, scattered Stratification, sheets, cribriform, scattered Cells Size Medium Medium to large Medium to large Medium to large Variance Slightly pleomorphic Pleomorphic Pleomorphic Pleomorphic Shape Polygonal, round, oval Polygonal, round, oval Polygonal, spindle, round, oval Polygonal, spindle, round, oval Cytoplasm Finely granular Finely granular, vacuolated Finely granular, vacuolated Finely granular, vacuolated Nucleus Shape Round to oval Round to oval Round to oval Round to oval Chromatin Fine, granular Fine, granular Granular, coarse Granular, coarse Nucleoli One or two, small One or two, large One or two, large One or two, large FNAC: fine needle aspiration cytology. TABLE 3 Immunohistochemical Expression of Androgen Receptor in Salivary Gland Tumors Tumor type No. of AR positive tumors FIGURE 5. A histologic section from Patient 3 shows salivary duct carcinoma with a cribriform pattern and central necrosis resembling comedo carcinoma of the breast (hematoxylin and eosin stain; original magnification, 200). noma pattern in which AR positive nuclei were observed. The remaining single sample of carcinoma (squamous cell carcinoma-like) in pleomorphic adenoma was negative for AR. Other salivary gland carcinoma samples and benign tumor samples were completely negative for AR. On imprint smears from patients with SDC (Patients 2 4), almost 100% of the neoplastic cell nuclei were strongly positive for AR (Fig. 7). There was no expression of ER or PgR in the SDC samples. DISCUSSION SDC is a high-grade, malignant tumor that demonstrates a propensity for invasive spread with early regional and distant metastases. 2 Although, Delgado et Malignant 8 of 36 Salivary duct carcinoma 6 of 6 Mucoepidermoid carcinoma 0 of 6 Acinic cell carcinoma 0 of 5 Adenoid cystic carcinoma 0 of 8 Epithelial-myoepithelial carcinoma 0 of 2 Squamous cell carcinoma 0 of 1 Basal cell adenocarcinoma 0 of 5 Carcinoma in pleomorphic adenoma 2 a of 3 Benign 0 of 21 Pleomorphic adenoma 0 of 10 Warthin tumor 0 of 10 Lymphadenoma 0 of 1 AR: androgen receptor. a Focal, AR positive cell nuclei were present in the comedocarcinoma-like lesions. al. 21 recently described low-grade SDC in contrast to the aggressive, high-grade SDC and reported that lowgrade SDC appeared biologically indolent, with bland cytologic and histologic features, the current report discusses high-grade SDC. Patients commonly present with a painless, rapidly growing, parotid mass, often with facial nerve involvement and cervical adenopathy. 2,3,5,6 Approximately 80% of reported patients have been males. 2,6,13,16 The age range at the time of presentation is years, with a peak incidence in the sixth and seventh decades of life. 2 Brandwein et al. 3 reviewed the literature on SDC and summarized the prognostic findings from SDC in 60 patients with follow-up. Local recurrence was seen in 39% of patients

5 348 CANCER (CANCER CYTOPATHOLOGY) October 25, 2001 / Volume 93 / Number 5 FIGURE 6. Androgen receptor (AR) immunostaining on a histologic section from Patient 2. Almost 100% of the tumor cells show a strong, positive reaction in the nuclei. The adjacent normal parotid gland shows no AR (biotin-streptavidin amplified method; original magnification, 100). FIGURE 7. Androgen receptor immunostaining is seen on an imprint smear from Patient 2. Many tumor cell nuclei are strongly positive (biotin-streptavidin amplified method; original magnification, 200). with SDC, lymphatic involvement was seen in 60%, and distant metastases were seen in 57%. The mortality rate was 55%, within a mean of 29 months. In our series, three patients died of recurrent or metastatic disease within 2 years., and one patient is alive with lung and brain metastases. Histologically, SDC may contain a combination of growth patterns similar to those seen in ductal carcinoma of the breast. Both intraductal and infiltrating components are recognized. 2 6 Extensive central comedo necrosis commonly is associated with the intraductal component. Papillary, cribriform, solid, or various combinations of these histologic patterns are observed. The infiltrating carcinoma consists of irregular glands and cords of compressed cells that frequently are associated with a prominent desmoplastic reaction. The individual cells are large and polygonal in shape, and they display a finely granular, vacuolated, eosinophilic cytoplasm, imparting an apocrine appearance to the cells. The cell borders are well defined. The nuclei are round to oval in shape, hyperchromatic, and moderately pleomorphic. Coarse chromatin, prominent nucleoli, and conspicuous mitotic figures are seen. Intracytoplasmic mucin usually is negative. In our patients, cribriform pattern and comedo necrosis frequently were observed, and intracytoplasmic PAS negative vacuoles often were present. The cytologic findings reflect the histology and also resemble breast carcinoma. The cytologic features of SDC have been reported in detail for several series Most of the reported patients show features of high-grade malignancy. The smears are cellular and contain cohesive, three-dimensional clusters and flat sheets of large, polygonal cells with abundant, finely granular cytoplasm. Some of the sheets of cells display an irregular branching or cribriform pattern as well as papillary cluster formations. Single cells with welldefined borders also are seen. The nuclei are enlarged and round to oval, and they show moderate pleomorphism. The chromatin is finely granular or coarse, and prominent nucleoli are present in the nuclei. Mitotic figures also are seen. Necrosis frequently is present in the background. Although the cytologic features of our patients were almost similar to those in previous series, we would like to stress the marked cytomorphologic variety and the flat sheets of tumor cells with a cribriform pattern. In FNA materials, differential diagnoses include high-grade mucoepidermoid carcinoma, squamous cell carcinoma, oncocytic carcinoma, adenoid cystic carcinoma, and adenocarcinoma not otherwise specified (NOS). 6,11,14 16 High-grade mucoepidermoid carcinoma is comprised of squamoid, intermediate, and rare mucous cells. The squamoid cells with marked atypia and frequent mitotic figures may mimic SDC. The presence of intermediate cells and mucous cells, however, argues against SDC. 16 Similarly, squamous cell carcinoma is comprised of round, ovoid, or enlarged atypical cells with dense nuclear chromatin and tumor necrosis; bare nuclei and keratin debris commonly may be encountered. Marked keratinization is a feature that excludes the diagnosis of both SDC and mucoepidermoid carcinoma. 16,22 Oncocytic carcinoma may present a differential diagnosis difficulty, because some SDCs may manifest oncocytic (apocrine-like) features. The marked cytonuclear atypia typically present in SDC and the infrequency of oncocytic carcinoma favor the former diagnosis. 16,23,24 Adenoid cystic carcinoma may contain cribriform structures, but characteristic amorphous mucoid globules

6 Cytology and AR of Salivary Duct Carcinoma/Moriki et al. 349 also are seen. Its cells are generally small, whereas those in SDC have larger cytoplasm. 9,10,14 Adenocarcinoma NOS may have diagnostic problems. This is a salivary gland carcinoma that shows glandular or ductal differentiation but lacks prominence of any of the histomorphologic features that characterize the other, more specific carcinoma types. If sufficient FNA materials cannot be obtained and if they show high-grade malignancy without specific cytomorphologic features, then the cytopathologist may elect to render a diagnosis of adenocarcinoma NOS. Although SDC occurs exclusively in males, metastatic adenocarcinoma from the breast may be indistinguishable from SDC on the basis of cytology alone. A review of the literature indicates that AR, a marker frequently detected in patients with prostatic adenocarcinoma, is expressed in 90% of patients with SDC, 18,19 whereas two common breast carcinoma markers, ER and PgR, are expressed in only 1.3% and 6% of patients with SDC, respectively, by immunohistochemistry. 6,18,19,25,26 In our six patients with SDC, ER and PgR were not expressed. This hormonal profile suggests that SDC, in contrast to its histologic similarity to breast carcinoma, is related immunophenotypically more closely to prostatic adenocarcinoma. 19 Expression of AR in patients with SDC was an incidental discovery. This discovery led to a study by Kapadia and Barnes 18 in which 12 SDC samples were stained for AR, and 11 samples were found positive. Fan et al. 19 also reported that 12 of 13 patients with SDC were positive for AR. In our study, all six patients with SDC were positive for AR, and cytologic smears also showed strong positive reactions on the tumor cell nuclei. Other salivary gland tumors were negative for AR, except two patients with carcinoma in pleomorphic adenoma. In these patients, AR positive nuclei were confined to the carcinoma areas that resembled comedo carcinoma of the breast. Although there were a few reported patients with SDC associated with pleomorphic adenoma, 5 we could not diagnose our samples as SDC because of small, localized lesions. It may be difficult to differentiate pure SDC from SDC in pleomorphic adenoma. However, a long clinical history of the tumor mass and the admixed pleomorphic adenoma features in FNA materials suggest the diagnosis of SDC in pleomorphic adenoma. Salivary gland metastasis from breast carcinoma may have diagnostic difficulties in FNA materials; however, it can be distinguished from SDC by immunostaining for ER, which is expressed commonly in breast carcinoma. 27 Clinical information may be the most important for distinguishing between them. A thorough investigation of cytologic smears and immunostaining for ER and AR may help in the differential diagnosis. In conclusion, the cytologic features of high-grade adenocarcinoma with a variety of cell morphologies flat sheets of tumor cells with a cribriform pattern and necrotic backgrounds are characteristic findings in patients with SDC. Immunostaining for AR on cytologic smears is useful for the diagnosis of SDC. REFERENCES 1. Kleinsasser O, Klein HJ, Hubner G. Salivary duct carcinoma: a group of salivary gland tumors analogous to mammary duct carcinoma. Arch Klin Exp Ohren Nasen Kehlkopfheild 1968;192: Ellis GL, Auclair PL. Malignant epithelial tumors. In: Rosai J (ed). Atlas of tumor pathology: tumors of salivary glands. Washington, DC: Armed Forces Institute of Pathology, 1996: Brandwein MS, Jagirdar J, Patil J, Biller H, Kaneko M. Salivary duct carcinoma (cribriform salivary carcinoma of excretory ducts): a clinicopathologic and immunohistochemical study of 12 cases. Cancer 1990;65: Seifert G, Batsakis JG, Brocheriou C, Cardesa A, Dardick I, Ellis GL, et al. World Health Organization international classification of tumors. Histological typing of salivary gland tumors. 2nd ed. Berlin: Springer-Verlag, Delgado R, Vuitch F, Albert-Saavedra J. Salivary duct carcinoma. Cancer 1993;72: Lewis JE, McKinney BC, Weiland LH, Ferreiro JA, Olsen KD. Salivary duct carcinoma: clinicopathologic and immunohistochemical review of 26 cases. Cancer 1996;77: Murrah VA, Batsakis JG. Pathology consultation. Salivary duct carcinoma. Ann Otol Rhinol Laryngol 1994;103: Gal R, Strauss M, Zohar Y, Kessler E. Salivary duct carcinoma of the parotid gland. Cytologic and histopathologic study. Acta Cytol 1985;29: Dee S, Masood S, Issacs JH Jr., Hardy NM. Cytomorphologic features of salivary duct carcinoma on fine needle aspiration biopsy: a case report. Acta Cytol 1993;37: Elsheikh TM, Bernacki EG Jr., Pisharodi L. Fine-needle aspiration cytology of salivary duct carcinoma. Diagn Cytopathol 1994;11: Simpson RHW, Robertson NJ, Arora DS, Saunders MW. Salivary duct carcinoma: a cytological and histopathological study. Cytopathology 1996;7: Colecchia M, Frigo B, Leopardi OM. Salivary duct carcinoma of the parotid gland. Report of a case with cytologic and immunocytochemical findings on fine needle aspiration biopsy. Acta Cytol 1997;41: Khurana KK, Pitman MB, Powers CN, Korourian S, Bardales RH, Stanley MW. Diagnostic pitfalls of aspiration cytology of salivary duct carcinoma. Cancer (Cancer Cytopathol) 1997; 81: Fyrat P, Cramer H, Feczko JD, Kratzer S, Layfield LJ, Eisenhut CC, et al. Fine-needle aspiration biopsy of salivary duct carcinoma: report of five cases. Diagn Cytopathol 1997;16: Garcia-Bonafe M, Catala I, Tarragona J, Tallada N. Cytologic diagnosis of salivary duct carcinoma: a review of seven cases. Diagn Cytopathol 1998;19: Klijanienko J, Vielh P. Cytologic characteristics and histomorphologic correlations of 21 salivary duct carcinomas. Diagn Cytopathol 1998;19:333 7.

7 350 CANCER (CANCER CYTOPATHOLOGY) October 25, 2001 / Volume 93 / Number Vinette-Leduc D, Yazdi HM, Payn G, Villeneuve N. Metastatic salivary duct carcinoma to the uterus: report of a case diagnosed by cervical smear. Diagn Cytopathol 1999;21: Kapadia SB, Barnes L. Expression of androgen receptor, gross cystic disease fluid protein, and CD44 in salivary duct carcinoma. Mod Pathol 1998;11: Fan CY, Wang J, Barnes EL. Expression of androgen receptor and prostatic specific markers in salivary duct carcinoma. An immunohistochemical analysis of 13 cases and review of the literature. Am J Surg Pathol 2000;24: Hermanek P, Sobin LH. TNM classification of malignant tumors. 4th ed. International Union Against Cancer. Berlin: Springer-Verlag, Delgado R, Klimstra D, Albores-Saavedra J. Low grade salivary duct carcinoma: a distinctive variant with a low grade histology and a predominant intraductal growth pattern. Cancer 1996;78: Klijanienko J, Vielh P. Fine needle sampling of salivary gland lesions VI. Cytology of 44 cases of primary salivary squamous cell carcinoma with histologic correlation. Diagn Cytopathol 1998;18: Abdul-Karim FW, Weaver MG. Needle aspiration cytology of an oncocytic carcinoma of the parotid gland. Diagn Cytopathol 1991;7: Harrison RF, Smallman LA, Young JA, Watkinson JC. Oncocytic carcinoma of the parotid gland: a problem in fine needle aspiration diagnosis. Cytopathology 1995;6: Barnes L, Rao U, Krause J, Contis L, Schwartz A, Scalamogna P. Salivary duct carcinoma. Part II: immunohistochemical evaluation of 13 cases for estrogen and progesterone receptors, cathepsin D and c-erbb-2 protein. Oral Surg Oral Med Oral Pathol 1994;78: Wick MR, Ockner DM, Mills SE, Ritter JH, Swanson PE. Homologous carcinomas of the breast, skin and salivary glands; a histologic and immunohistochemical comparison of ductal mammary carcinoma, ductal sweat gland carcinoma and salivary duct carcinoma. Am J Clin Pathol 1998; 109: Nizzoli R, Bozzetti C, Naldi N, Guazzi A, Gabrielli M, Michiara M, et al. Comparison of the results of immunocytochemical assays for biologic variables on preoperative fine-needle aspirates and on surgical specimens of primary breast carcinomas. Cancer (Cancer Cytopathol) 2000;90:61 6.