Faculty Bibliography

We assessed the usefulness of fine-needle aspiration biopsy (FNAB) in the diagnosis of mediastinal germ cell tumors (GCTs). In the archives of 3 pathology departments, we found records of 7 patients with mediastinal GCTs who underwent mediastinal FNAB as part of the diagnostic workup. The FNAB smears, results of the immunocytochemical analysis, the corresponding histologic findings, and the clinical charts were reviewed. All patients were men (age range, 24-44 years; mean, 32 years). One patient had a history of testicular mixed GCT 10 years earlier. The 6 primary mediastinal GCTs consisted of 3 seminomas and 3 yolk sac tumors. Based on the cytologic features and immunocytochemicalfindings, a cytologic diagnosis of GCT was made in 5 cases, including the case of metastatic GCT In 2 cases, the differential diagnosis was between poorly differentiated carcinoma and GCT Results of ancillary studies were noncontributory in 1 case, and the aspirate of the second case demonstrated extensive necrosis. Our findings demonstrate that a diagnosis of mediastinal GCT, primary or secondary, can be established with a high degree of accuracy on the basis of FNAB. Immunocytochemical analysis helps confirm the diagnosis

OBJECTIVE: To describe the morphologic spectrum of metastatic malignant melanoma (MM) cells involving the breast and to explore the diagnostic utility of HMB45, Mart-1, Melan-A and T311 (antityrosinase) antibodies in fine needle aspiration material of MM metastatic to the breast. STUDY DESIGN: Cytologic material from 21 cases (18 women) was reviewed for cytomorphology (epithelioid, spindled, mixed) and immunocytochemical staining attributes for Mart-1, HMB45, T311, Melan-A and cytokeratin based on tissue availability. RESULTS: Seventeen cases (81%) demonstrated epithelioid cell morphology, with 14% exhibiting mixed and 5% spindled morphologies. All 21 cases (100%) were immunoreactive with Mart-1 antibody, with 81% (17/21) immunoreactive for HMB45. In 38% of cases there was a similar percentage of cells immunoreactive for Mart-1 and HMB45, while 48% showed a higher percentage of cells immunoreactive for MART-1 than HMB45. Immunoreactivity with T311 was seen in 8 of 11 cases tested (73%). All six cases tested (100%) were immunoreactive with Melan-A. Staining for cytokeratin was negative in all eight cases tested. CONCLUSION: Because the majority of MM metastatic to the breast shows epithelioid cell morphology, it may mimic primary breast carcinoma. Mart-1 should be part of the immunocytochemical panel utilized to confirm the diagnosis of MM metastatic to the breast

Discrepant results in effusion immunocytochemistry are often the result of specimen processing. Smears, cytospins, cell blocks, and monolayer preparations have all been used in various published studies; thus, there is no consistency in the immunostaining process for cytology to compare with the surgical pathology 'gold standard' results. We sought to evaluate optimal specimen preparation for the immunostaining of effusion samples. Fourteen reactive and 15 malignant effusion samples (various epithelial/mesothelial neoplasms) were each prepared in three forms: air-dried cytospins (postfixed in ethanol), formalin-fixed, paraffin-embedded cell blocks, and liquid-based thin-layer (ThinPrep, CYTYC, Boxborough, MA) processing. All slides were immunostained with antibodies commonly used in effusion cytology: HBME-1, calretinin, E-cadherin, BerEP4, B72.3, LeuM1, and CA19-9. Cytospin and ThinPrep samples performed in a similar manner: high background staining was encountered in 66% of cases, most evident in three-dimensional clusters of cells. In addition, membrane staining patterns were difficult to interpret. Cell blocks provided the best milieu for morphologic interpretation, with less background staining (only 17% of cases) and results that most closely approximated those reported in the surgical pathology literature. The cost per test for cell block immunocytochemistry was also the most economical for our laboratory

Myofibroblastoma of the breast is a rare benign stromal neoplasm, which occurs primarily in men. Classical myofibroblastoma is a circumscribed, nonencapsulated tumor comprised of bipolar fusiform cells arranged randomly, or in fascicles alternating with broad collagenous bands. Additional histologic variants (the cellular, collagenized, infiltrative, and epitheloid types) have been described. Several case reports describe the cytopathologic features of the classical and cellular variants. We report on a 70-yr-old woman, who presented with a circumscribed mass in her left breast. Aspiration biopsy showed paucicellular smears with singly distributed atypical spindle-shaped cells and rare fragments of collagenized stroma, raising suspicion of a phyllodes tumor. Histologic examination revealed spindle-shaped cells distributed in a diffusely collagenized stroma. Some nuclear atypia was present. To the best of our knowledge, this is the first case reporting the cytologic features of the collagenized variant of myofibroblastoma. Although we believe a specific diagnosis of myofibroblastoma can be rendered in a male based on the typical cytologic and clinical findings in the classical type, the variant forms are difficult to classify accurately and require excision for a definitive diagnosis.

Loss of heterozygosity (LOH) at the 3p region is found in up to 50% of epithelial ovarian neoplasms. The von Hippel-Lindau (VHL) gene at the 3p25 locus is one of the tumor-suppressor genes located at 3p. The role, if any, of the VHL gene locus is not clear in ovarian carcinogenesis. We analyzed primary and metastatic ovarian clear-cell carcinomas (OCCC) for LOH at 3p25 to determine its frequency and its diagnostic utility as an adjunctive tool in the differential diagnosis of metastatic clear-cell carcinomas. Microdissection followed by single-step DNA extraction and polymerase chain reaction (PCR) amplification, using two polymorphic markers flanking the VHL gene locus, was done on archival histology and cytology samples from 9 patients with metastatic OCCC. Of the informative cases, 43% of the metastatic and 50% of the primary OCCC showed LOH. LOH at the VHL gene locus is not uncommon in clear-cell ovarian carcinoma. LOH at 3p25 in cytologic specimens may be a valuable adjunct in the diagnosis of OCCC metastasis in cytologically equivocal cases. OCCC should enter the differential in clear-cell carcinomas of unknown primary that show LOH at 3p25. Published 2001 Wiley-Liss, Inc

OBJECTIVE: To determine if repeating the Pap smear (PS) at colposcopy offers added benefit in the detection of cervical squamous intraepithelial lesions (SILs). STUDY DESIGN: Eight hundred fifty-two women were subjects of this study. Patients with cervical SIL were defined as women with SIL on the repeat PS, or SIL on the colposcopic cervical biopsy (bx) or a negative repeat PS and bx but confirmed SIL on both the previous and follow-up PS or bx. The sensitivities of repeat PS and bx in detecting SIL were calculated. The chi 2 test was used to assess statistical significance. The total cost of repeating the PS was calculated by multiplying the total number of patients (852) by the estimated cost of a single PS ($25). RESULTS: The sensitivities of repeat PS, bx and PS/bx combined were .89, .69 and .92 for low grade SIL (LSIL) and .74, .77 and .98 for high grade SIL (HSIL), respectively (P < .0001). Sixteen percent of the HSIL and 28% of the LSIL cases were diagnosed on repeat PS only (negative bx). If repeat PS was omitted, $21,300 would have been saved

Rhodococcus equi is a common cause of pneumonia in animals. Human infection is rare. Increasing number of cases are being reported in immunosuppressed individuals mostly associated with HIV infection, but also in solid organ transplant recipients and leukemia/lymphoma patients. We report on an adult male who developed pneumonia and gastroenteritis 4 mo after receiving a renal transplant. CT scan of the lungs showed a dominant 2.5-cm upper lobe lung mass and smaller bilateral nodules. He underwent a diagnostic bronchoscopy with fine-needle aspiration biopsy of the largest lung nodule. Smears showed histiocytic granulomatous inflammation, foamy macrophages, and acute inflammatory exudate. Scattered foamy macrophages displayed intracellular coccobacilli identifiable on Diff-Quik stain. A few cells with changes suggestive of viral inclusions were identified. Cytomegalovirus (CMV) immunostain was positive in the cell block sections. Lung cultures grew R. equi. To the best of our knowledge, this is the first report of coinfection with R. equi and CMV.

Endometrioma in an operative scar is rare. The majority of patients have no prior history of endometriosis, and symptoms may mimic postoperative hernias. Fine-needle aspiration biopsy (FNAB) can be a valuable diagnostic aid in the evaluation of these subcutaneous abdominal masses. We present the cytologic findings in three cases of abdominal wall endometriomas diagnosed by FNAB. The patients ranged from 31 to 51 years of age. None had a history of endometriosis, but all had prior abdominal operations (two abdominal hysterectomies for fibroids and one cesarean section). They presented 6 months to 7 years later with painful subcutaneous abdominal nodules in their scars ranging from 2 to 6 cm. FNAB was performed by a cytopathologist. The smears were cellular and comprised two distinct cell populations. An epithelial component consisted of flat sheets of polygonal cells with round to oval nuclei and scant cytoplasm. The second component consisted of clusters of fusiform stromal cells. Numerous hemosiderin-laden macrophages were noted in the background. Cytokeratin highlighted the epithelial clusters, and vimentin stained the stromal cells. Electron microscopy showed two epithelial cell types: one with cilia and abundant rough endoplasmic reticulum and the other with numerous microvilli and scattered mitochondria indicative of endometrial differentiation. FNAB provided a rapid and accurate preoperative diagnosis in each case