COVID-19 post-vaccination lymphadenopathy: A review of the use of fine needle aspiration cytology.

COVID-19 vaccine-associated clinical lymphadenopathy (C19-LAP) and subclinical lymphadenopathy (SLDI), which are mainly detected by 18F-FDG PET-CT, have been observed after the introduction of RNA-based vaccines during the pandemic. Lymph node (LN) fine needle aspiration cytology (FNAC) has been used to diagnose single cases or small series of SLDI and C19-LAP. In this review, clinical and LN-FNAC features of SLDI and C19-LAP are reported and compared to non-Covid (NC)-LAP. A search for studies on C19-LAP and SLDI histopathology and cytopathology was performed on PubMed and Google Scholar, on 11 January 2023. Reports on LN-FNAC of C19-LAP were retrieved. A total of 14 reports, plus one unpublished case of C19-LAP observed in our institution, diagnosed by LN-FNAC were included in a pooled analysis and compared to the corresponding histopathological reports. In total, 26 cases were included in this review, with a mean age of 50.5 years. Twenty-one lymphadenopathies assessed by LN-FNAC were diagnosed as benign, and three cases as atypical lymphoid hyperplasia; the latter were subsequently confirmed as benign (one by repetition of LN-FNAC, two by histological control). One case of mediastinal lymphadenopathy in a patient suffering from melanoma was reported as reactive granulomatous inflammation, while one unsuspected case was diagnosed as metastasis from melanoma. In all cases, the cytological diagnoses were confirmed by follow-up or excisional biopsy. The high diagnostic value of LN-FNAC in excluding malignant processes was extremely useful in this context and may be particularly valuable when CNB or histological excisions are difficult to perform, as was the case during Covid lockdowns.

A Rare Case of Castleman Disease Presenting as an Ovarian Tumor.

Castleman disease (CD) is a rare lymphoproliferative disorder of unknown etiology. Its most common location is the mediastinum, but many other sites have been reported. We report a case of primary CD of the ovary, a rare localization with only 2 cases including the present case described in the world literature to date. A 58-yr-old woman who initially presented with abdominal pain underwent computed tomography scan which showed bilateral well-circumscribed solid adnexal masses. Because an ovarian bilateral tumor was suspected the patient was treated with a hysterectomy and bilateral salpingo-oophorectomy and the histopathologic examination confirmed the diagnosis of CD hyaline-vascular type of the right ovary associated with a contralateral fibroma. Three years after surgery the patient is alive and well and shows no signs of recurrent disease. The occurrence of this rare presentation of CD is the subject of this report. The problems of differential diagnosis with the most frequent lesions of the female pelvis are also discussed.

Discordance rate of HER2 status in primary gastric carcinomas and synchronous lymph node metastases: a multicenter retrospective analysis.

BACKGROUND: The assessment of human epidermal growth factor receptor 2 (HER2) gene amplification is essential in order to identify those patients affected by advanced gastric cancer who may benefit from Trastuzumab targeted therapy. MATERIALS AND METHODS: With the aim to investigate the concordance rate in HER2 status between primary gastric carcinoma (GC) and synchronous lymphnode metastases, we investigated HER2 status in a cohort of 108 surgical formalin-fixed paraffin-embedded specimens of GC and matched synchronous metastatic lymph nodes collected from three different units of Anatomic Pathology in southern of Italy. Fleiss-Cohen weighted k statistics were used to assess the concordance rate of HER2 status. RESULTS: HER2 amplification was observed in 17% of primary GCs and the overall concordance rate with corresponding nodal metastases was 90.74%. Changes in HER2 status between primary GC and matched synchronous metastases were evidenced in 10 (9.26%) cases. Of these, 6 cases were HER2 amplified in the primary GC and not amplified in the metastases, while 4 were HER2 not amplified in the primary tumour and amplified in the lymph node metastases. CONCLUSIONS: Although at present the simultaneous determination of HER2 in advanced gastric cancer and corresponding metastatic lymph nodes is not mandatory, the possibility that the synchronous metastases of GC have a different HER2 status from that of the primary tumour is of remarkable significance; Indeed this may have influence on the therapeutic management and prognosis of the patients.

Survival predictors of radioiodine-refractory differentiated thyroid cancer treated with lenvatinib in the real-life.

CONTEXT: Lenvatinib is approved for the treatment of radioiodine-refractory differentiated thyroid cancer (RR-DTC). The definition of predictive factors of survival is incomplete. OBJECTIVE: To identify pre- and post- treatment survival predictors in a real-life cohort of RR-DTC treated with lenvatinib. DESIGN: Multicenter, retrospective, cohort study. SETTING: Three Italian thyroid cancer referral centers. PARTECIPANTS: 55 RR-DTC treated with lenvatinib. MAIN OUTCOME MEASURES: Progression-free survival (PFS) and overall survival (OS). RESULTS: Lenvatinib was the first-line kinase-inhibitor in 96.4% of subjects. Median follow-up was 48 months. Median PFS and OS were 26 (95% CI 19.06-32.93) and 70 months (95% CI 36-111.99), respectively. Pre-treatment setting: Eastern Cooperative Oncology Group (ECOG) performance status was independently related to PFS (p < 0.001; HR 18.82; 95% CI 3.65-97.08: score 0-1 as reference) and OS (p = 0.001; HR 6.20; 95% CI 2.11-18.20; score 0-1 as reference); radioactive iodine (RAI)-avidity was independently related to PFS (p = 0.047; HR 3.74; 95% CI 1.01-13.76; avid disease as reference). Patients with good ECOG status (0-1) and RAI-avid disease obtained objective response in 100% of cases and achieved a median PFS of 45 months without any death upon a median follow-up of 81 months. Post-treatment setting: best radiological response independently predicted PFS (p = 0.001; HR 4.6; 95% CI 1.89-11.18; partial/complete response as reference) and OS (p = 0.013; HR 2.94; 95% CI 1.25-6.89; partial/complete response as reference). CONCLUSIONS: RR-DTC with good performance status and RAI-avid disease obtain the highest clinical benefit from lenvatinib. After treatment initiation, objective response was the only independent survival predictor.

Cytological diagnosis of adult-type fibrosarcoma of the neck in an elderly patient. Report of one case and review of the literature.

BACKGROUND: Fibrosarcoma (FS) accounts for about 3% of all soft tissue sarcomas. It may arise in any area of the body, but it is relative rare in the head and neck district. Fine-needle cytology (FNC) is widely used in the diagnosis of neoplastic and non-neoplastic lesions of soft tissue. This article describes a case of FS of the neck diagnosed by FNC. METHODS: FNC was performed in a sub-fascial supraclavicular mass of an elderly patient under ultrasound (US) control. FNC was used to prepare cytological smears that were conventionally and immunocytochemically (ICC) stained. RESULTS: Smears showed a monomorphous spindle cell population and were positive at ICC for Vimentin and negative for CKAE1AE3, Actin, S-100, CD68, CT and PAX-8. The cytological diagnosis was confirmed by histological diagnosis. The patient underwent surgical resection and subsequent radiotherapy. CONCLUSIONS: FNC diagnosis of FS is reliable and accurate and may be conveniently used in the scheduling of surgical procedures, when needed, avoiding the treatment of benign nodules.

Early cytological diagnosis of extranodal stage I, primary thyroid Non-Hodgkin lymphoma in elderly patients. Report of two cases and review of the literature.

BACKGROUND: Primary thyroid lymphomas (PTLs) account for 5% of thyroid malignant tumors and often develop in patients with Hashimoto Thyroiditis (HT). Fine-needle cytology (FNC) is widely used in the diagnosis of thyroid nodules, including those arising in HT. Two PTL cases in HT elderly patients are here described and discussed. METHODS: FNC was performed in rapidly enlarged thyroid nodules of 2 elderly patients under ultrasound (US) control. FNC was used to prepare conventional cytologic smears, immunocytochemistry (ICC) and flow cytometry (FC) assessment of cell populations. RESULTS: The above cases were diagnosed as well differentiated, small B-cell and diffuse large B-cell thyroid lymphomas, respectively, by means of FNC. The histological diagnoses were mucosa-associated non Hodgkin lymphoma (MALT) and diffuse large B-cell lymphoma (DLBCL), confirming FNC diagnoses, and patients were treated accordingly. CONCLUSIONS: FNC diagnosis of PTL is reliable and accurate; it may be conveniently used in the clinical practice since it provides indications for appropriate therapeutic procedures or diagnostic surgery, and avoids to treat benign nodules.

Cytological diagnosis of thyroid nodules in Hashimoto thyroiditis in elderly patients.

BACKGROUND: Long standing Hashimoto Thyroiditis (HT) causes shrinking and atrophy of the thyroid, but may also lead to diffuse enlargement of the gland and/or formation of nodules. These nodules should be differentiated from papillary thyroid carcinoma (PTC) and primary thyroidal non-Hodgkin lymphoma (PTL), which are possible complications of HT, and require pre-surgical diagnoses and different treatments. METHODS: Thirty-four elderly patients (≥ 65 yrs) with HT and diffuse or nodular enlargement of the thyroid underwent ultrasound (US)-guided FNC. Smears were routinely stained and evaluated; additional passes were used for flow cytometry (FC) assessment of lymphoid infiltrate in 6 cases. RESULTS: The cytological diagnosis was HT in 12 cases with prevalence of Hurtle cells in 2 cases, PTC in 1 case and PTL in 2 cases. FC assessed the reactive, non-lymphomatous nature of the lymphoid infiltrate in 5 cases and demonstrated light chain restriction, hence the lymphomatous nature of the lymphoid infiltrate in 2 cases of PTL. CONCLUSIONS: FNC plays a key role in the clinical surveillance and pre-surgical diagnosis of diffuse enlargement and nodular presentation of HT in elderly patients. FNC can correctly diagnose HT, PTC and PTL indicating the need for surgery and its extension in suspicious or neoplastic cases, leaving other cases to the medical treatment and clinical surveillance.

[Sub-acute thyroiditis in a patient on immunosuppressive treatment]. / Tiroidite subacuta in un paziente in trattamento immunosoppressivo.

Sub-acute thyroiditis or De Quervain's thyroiditis is a viral, inflammatory disease which causes the serum release of thyroidal hormones and hyperthyroidism. The pathogenesis of thyroid follicle damage is unclear because the exclusive viral action or a concomitant autoimmune component, determined by the lymphoid infiltrate remain to be assessed. We describe the case of a patient under immunosuppressive treatment, who developed sub-acute thyroiditis with hormone release and hyperthyroidism. The patient, while was under immunosuppressive treatment for kidney transplant, exhibited a clinical picture and hormonal profile of hyperthyroidism. Thyroid scintiscan exhibited an extremely low uptake. Fine-needle cytologic diagnosis was granulomatous sub-acute thyroiditis (De Quervain's thyroiditis). This case suggests the primary or even exclusive role of the viral infection in hormone release and hyperthyroidism in sub-acute thyroiditis, excluding an autoimmune component.

Non-urothelial lesions of the urinary bladder A 14.5-year, single-institution review.

CONTEXT: In contrast to urothelial cancers, non-urothelial neoplasms involving the bladder are uncommon and often diagnostically challenging. These lesions include a variety of benign and malignant tumors often presenting with a combination of hematuria and the presence of a polypoid lesion at cystoscopy that may lead to an erroneous diagnosis of urothelial cancer. OBJECTIVE: We set out to quantify and classify the spectrum of non-urothelial lesions diagnosed in our institution, and briefly review the relevant literature on each lesion, with a focus on differential diagnosis and potential pitfalls. DESIGN: We performed a retrospective review (Jan 2008 - Jun 2022) of the cases diagnosed on TURB material at our institution. RESULTS: Out of 4071 TURB specimens, a total of 66 (1.62 %) non-urothelial lesions were identified. Most of these lesions were malignant (n = 51, 77 %), with metastases being the most common (n = 40, 60.6 %), followed by non-Hodgkin lymphoma (n = 8, 12 %). The remaining cases were benign lesions (n = 15, 22.7 %), with the most common being inflammatory myofibroblastic tumor (n = 4, 6.1 %) and endometriosis (n = 3, 4.5 %). CONCLUSIONS: In this retrospective case series, we identified various malignant and benign entities, some of which have been rarely reported in the bladder, such as paragangliomas, inflammatory myofibroblastic tumor, and leiomyosarcoma. These lesions may macroscopically and histologically mimic urothelial carcinoma. Because of their relative rarity and diagnostic overlap with conventional urothelial tumors, the pathologist should always keep in the mind the possibility of non-urothelial lesions.

Vulvar lymphoedematous pseudotumours mistaken for aggressive angiomyxoma: report of two cases.

BACKGROUND: We describe 2 cases of vulvar pseudotumour due to lymphatic obstruction with chronic lymphoedema of unknown cause that presented as a solitary mass that mimicked aggressive angiomyxoma. MATERIAL AND METHODS: Both patients presented with a vulvar mass without medical history of trauma, surgery in the anogenital region or skin diseases. One patient was overweight (BMI = 26). Both surgically resected vulvar specimens were represented by a polypoid mass with a soft and a gelatinous cut surface. RESULTS: Histologically, the presence of an abundant oedematous stroma with spindle-shaped cells and numerous thin-walled small-to-medium vessels may be confused with an aggressive angiomyxoma. The diagnostic key was represented by the massive oedema, rather than myxoid stroma, with the presence of dilated, tortuous lymphatic channels (some surrounded by clusters of lymphocytes) in the dermis. CONCLUSION: The recognition of these lesions is important because they may be the cause of problems in differential diagnosis and therapeutic management. In fact, such lesions can be mistaken from both the clinical and histological perspective as a primitive tumour of the vulva-like aggressive angiomyxoma. However, these lesions are not true neoplasms and are likely due to lymphatic obstruction with lymphoedema. A simple surgical excision with vulvoplasty is curative.

Hepatoid carcinoma of the ovary with sex cord stromal tumor: a previously unrecognized association.

BACKGROUND: Hepatoid carcinoma (HC) of ovary is a rare type of epithelial tumor composed mainly of epithelioid cells with abundant acidophilic cytoplasm, histologically indistinguishable from hepatocellular carcinoma. We report a previously unrecognized case of HC of ovary concurrent with a Sertoli cell tumor. CASE REPORT: A 42-year-old woman patient with a long-term history of hepatitis C presented with a mass of left ovary without evidence of hepatic tumor. After initial diagnosis of primary ovarian carcinoma (FIGO Stage I), she had experienced a first recurrence in upper abdomen. Histologically, the primary tumor was composed of epithelioid cells with "hepatoid features" in association with a sex cord stromal tumor of Sertoli-type. Immunohistochemistry hepatoid cells stained positively for hepatocyte paraffin-1, alpha-fetoprotein and alpha-1 antitrypsin; moreover, Sertoli-type cells were positive for alpha-inhibin, calretinin and CD99. A final diagnosis of HC concurrent with Sertoli-type tumor was made. CONCLUSION: The occurrence of this unreported association of HC with Sertoli-like tumor, the problems of differential diagnosis and therapeutic management of these tumors are the subject of this presentation. A diagnosis of ovarian metastasis from hepatocellular carcinoma is easy in patients with known primary tumor of liver and should be always excluded in these cases as an hepatoid variant of yolk sac tumor. Immunohistochemistry is not useful in these cases. However, a combination of clinical and pathological features is necessary for a correct diagnosis.

Hepatocellular carcinoma metastatic to the kidney mimicking renal oncocytoma.

BACKGROUND: Renal metastases of hepatocellular carcinoma (HCC) are very rare. To our knowledge only five cases have been reported to the present; all had a well-known primary HCC. METHODS: We describe the clinico-pathological features of a rare case of HCC metastatic to the kidney in which the renal mass was the clinical debut of disease. The patient was a 54-year-old woman previously submitted to orthotopic liver transplantation, who underwent left nephrectomy for a renal mass. RESULTS: Histologically, the tumor was composed mainly of epithelioid cells with homogeneous acidophilic cytoplasm resembling oncocytoma or primary renal carcinoma with oncocytic features. A correct diagnosis was made on the basis of positive immunostaining for hepatocyte paraffin 1. CONCLUSIONS: Metastasis to the kidney is a rare complication that should be considered whenever a renal mass is present in patients with HCC. Since HCC may histologically resemble primary renal tumors such as oncocytoma, pathologists must be aware of this possibility above all in patients referred for liver transplantation and treated with immunosuppressant drugs. Immunohistochemistry is particularly helpful to establish a precise diagnosis in cases of doubt.

Monotypic epithelioid angiomyolipoma of the adrenal gland: an unusual site for a rare extrarenal tumor.

Epithelioid angiomyolipoma (AML) is an uncommon renal mesenchymal tumor with malignant potential and is frequently associated with tuberous sclerosis. Extrarenal AMLs are rare, and to the best of our knowledge, this is the first reported case of a primary monotypic epithelioid AML of adrenal gland in a patient without evidence of tuberous sclerosis. The patient is a 42-year old man who presented with retroperitoneal hemorrhage resulting from spontaneous rupture of adrenal mass. Histologically, the tumor showed a prominent component of epithelioid smooth muscle cells with slightly pleomorphic nuclei, sometimes with prominent nucleoli and eosinophilic cytoplasm resembling oncocytic tumors. Epithelioid cells were positive for melanoma (HMB45 and positive MelanA) and smooth muscle markers (alpha-smooth muscle-specific actin), but not for epithelial markers (cytokeratin, EMA). Differential diagnosis from renal cell carcinoma, adrenal gland carcinoma, and metastatic carcinoma is often challenging because of its epithelioid morphology. Because primary and secondary malignant tumors are much more common and aggressive neoplasms, establishing the correct diagnosis has important therapeutic and prognostic implications.

Combined analysis of galectin-3 and BRAFV600E improves the accuracy of fine-needle aspiration biopsy with cytological findings suspicious for papillary thyroid carcinoma.

Ten to fifteen percent of fine-needle aspiration biopsy (FNAB) of thyroid nodules are indeterminate. Galectin-3 (Gal-3) and the oncogene BRAFV600E are markers of malignancy useful to improve FNAB accuracy. The objective of this study was to determine whether the combined analysis of Gal-3 and BRAFV600E expression in thyroid aspirates could improve the diagnosis in FNAB with suspicious cytological findings. Two hundred and sixty-one surgical thyroid tissues and one hundred and forty-four thyroid aspirates were analyzed for the presence of the two markers. In surgical specimens, Gal-3 expression was present in 27.4% benign nodules, 91.9% papillary (PTC) and 75% follicular (FTC) thyroid carcinomas. BRAFV600E was not detected in 127 benign nodules, as well as in 32 FTCs, while was found in 42.9% PTC. No correlation was found between BRAF mutation and Gal-3 expression. Forty-seven consecutive FNAB suspicious for PTC were analyzed for the presence of the two markers. Of these nodules, 23 were benign at histology, 6 were positive for Gal-3, none displayed BRAFV600E, and 17 were negative for both the markers. Twenty suspicious nodules were diagnosed as PTC and four FTCs at histology. Of these 24 carcinomas, 9 resulted positive for BRAFV600E, 17 for Gal-3, and 22 for one or both the markers. The sensitivity, specificity, and accuracy for the presence of Gal-3 and/or BRAFV600E were significantly higher than those obtained for the two markers alone. Notably, the negative predictive value increased from 70.8 to 89.5%. In conclusion, the combined detection of Gal-3 and BRAFV600E improves the diagnosis in FNAB with cytological findings suspicious for PTC and finds clinical application in selected cases.

Small cell neuroendocrine carcinoma of the endometrium with pulmonary metastasis: A clinicopathologic study of a case and a brief review of the literature.

Neuroendocrine carcinomas (NEC) of the female genital tract are aggressive and rare tumors that usually involve the cervix and ovary, and are seen rarely in the endometrium in perimenopausal or postmenopausal women. We presented a case of a73 year-old postmenopausal woman with vaginal bleeding and abdominal pain. A subsequent computerized tomography (CT) scan of pelvis showed an enlarged uterus (20,0 × 12,0 cm) with para-aortic and pelvic lymph node metastases. She underwent surgical debulking and staging of an endometrial tumor with omental metastasis and positive lymph nodes. The pathological diagnosis was primary small cell carcinoma (SCC) combined with endometrioid carcinoma of uterine corpus. Her final FIGO stage was IVB. Three months after surgery CT-total body showed a metastasis to left lung of SCC. Because the small-cell component of endometrial tumor showed a strong positivity for TTF1 as pulmonary counterpart a differential diagnosis with a primary small cell carcinoma of the lung should be made. Identifying an appropriate therapeutic management for SCC of endometrium is challenging since these are extremely rare tumors. An optimal initial therapeutic approach to this rare disease, especially at an advanced stage, has not yet been clearly defined. However, in these a multidisciplinary therapy, including surgery, chemotherapy, and radiotherapy represent until this time the only therapeutic option.

The diagnostic accuracy of fine-needle cytology of Hurthle cell lesions; A comprehensive cytological, clinical and ultrasonographic experience.

BACKGROUND: Fine-needle cytology (FNC) diagnosis and pre-operative classification of Hurthle cells (HC) lesions may be difficult. Rapid on-site evaluation (ROSE) enhances the efficiency of FNC, mainly when utilized in close combination to clinical and ultrasound (US) data. OBJECTIVE: to describe an experience on HC FNC with contextual clinical,US and ROSE evaluation and assess if this comprehensive approach improves the FNC accuracy of HC lesions. METHODS: FNC of 112 HC lesion were diagnosed and classified, according to the Bethesda system, by clinical, US and ROSE in one year. All the cases were controlled by follow-up and histology when performed. RESULTS: Eighty-five cases were diagnosed HC rich goiter or Hashimoto thyroiditis and were classified THY2; 5 cases were diagnosed hyperplastic nodular goiter and classified THY3A. Eight cases were diagnosed suspect neoplasia and classified THY3B. Two cases were diagnosed suspect HC papillary thyroid carcinoma (PTC) and classified THY4 and 2 cases were diagnosed HC-PTC and classified THY5. THY3B, THY4, THY5 and 1 THY3A were histologically controlled. FNC were confirmed in 14 out of the 17 THY3-THY5 cases. CONCLUSIONS: A comprehensive diagnostic approach that include FNC, clinical data, US and ROSE improves the diagnosis and classification of HC lesions.

p27Kip1 is expressed in proliferating cells in its form phosphorylated on threonine 187.

BACKGROUND: G1/S cell cycle progression requires p27Kip1 (p27) proteolysis, which is triggered by its phosphorylation on threonine (Thr) 187. Since its levels are abundant in quiescent and scarce in cycling cells, p27 is an approved marker for quiescent cells, extensively used in histopathology and cancer research. METHODS: However here we showed that by using a specific phosphorylation site (pThr187) antibody, p27 is detectable also in proliferative compartments of normal, dysplastic and neoplastic tissues. RESULTS: In fact, whereas un-phosphorylated p27 and MIB-1 showed a significant inverse correlation (Spearman R = -0.55; p < 0,001), pThr187-p27 was positively and significantly correlated with MIB-1 expression (Spearman R = 0.88; p < 0,001). Thus proliferating cells only stain for pThr187-p27, whereas they are un-reactive with the regular p27 antibodies. However increasing the sensitivity of the immunocytochemistry (ICH) by the use of an ultra sensitive detection system based on tiramide signal amplification, simultaneous expression and colocalisation of both forms of p27 was shown in proliferating compartments nuclei by double immunofluorescence and laser scanning confocal microscopy studies. CONCLUSION: Overall, our data suggest that p27 expression also occurs in proliferating cells compartments and the combined use of both regular and phospho- p27 antibodies is suggested.

Fine needle cytology of endometriosis: experience with 10 cases.

OBJECTIVE: To evaluate whether commonly used cytologic criteria for the diagnosis of endometriosis are sufficiently specific, to assess the possible role of special methods in the differential diagnosis and to assess the clinical meaning and drawbacks of a cytopathologic diagnosis of endometriosis by fine needle aspiration. STUDY DESIGN: We retrieved 10 cases of endometriosis from our files that had been diagnosed primarily by fine needle cytology (FNC) with subsequent tissue study. In some cases additional cytospin preparations and/or smears had been used for cytochemistry (periodic acid-Schiff stain, mucicarmine) or immunocytochemistry (pan-cytokeratin, cytokeratin 7, vimentin, CD10) using a 3-step streptavidin-biotin-immunoperoxidase reaction. RESULTS: The cell pattern and immunocytochemical profile of the cases suggested a diagnosis of endometriosis. All cases were histologically confirmed. CONCLUSION: With optimal preparations a confident cytologic diagnosis of endometriosis may be made with ease, permitting correct treatment of the disease and, in selected cases, planning of preoperative pharmacologic therapy.

Oncocytic variant of mucoepidermoid carcinoma: a diagnostic challenge for the pathologist.

Oncocytic mucoepidermoid carcinoma of the salivary gland is rare. We report a 48-year-old man who presented with a slowly growing right parotid mass. A preoperative fine needle aspiration showed exclusively oncocytic cells and cellular debris. A first diagnosis of Warthin tumor or myoepithelioma was made. The patient underwent a superficial parotidectomy, and her postoperative course was uneventful. Histologically, the tumor was composed of solid nests and cystic gland containing clear mucoid material, lined predominantly with oncocytes and few mucous goblet cells. A final diagnosis of oncocytic variant of mucoepidermoid low-grade carcinoma was made. The recognition of this variant is important, because may be easy confused with most frequent benign tumor with oncocytic cells; in this case a complete surgical excision and long-term clinical follow-up are an adequate management.