Cytologic examination of the body cavity fluid is very important because the specimens represent a significant percentage of nongynecologic samples and this cytologic examination may be the first, best or only chance for making the diagnosis of an underlying malignancy. The purposes of body cavity fluid examination are to correctly identify cancer cells and if possible, to identify the tumor types and primary sites when presented with unknown primary tumor sites. The most important basic differential diagnosis is that of benign and reactive disease vs malignant disease. Reactive mesothelial cells are a consistent population in body cavity fluid, and these are the most versatile cells in the body. Due to the specific environment of the body cavity, the exfoliated reactive mesothelial cells may show significant morphologic overlap with the morphology of cancer cells. With a focus on the differential points between reactive mesothelial cells and metastatic adenocarcinoma cells, the practical diagnostic approaches, the diagnostic clues and the pitfalls to achieve a correct diagnosis are presented in this review.
Adenocarcinoma ; Diagnosis, Differential ; Neoplasms, Unknown Primary

BACKGROUND: Up to 15% of all patients with brain metastases have no clearly detected primary site despite intensive evaluation, and this incidence has decreased with the use of improved imaging technology. Radiosurgery has been evaluated as one of the treatment modality for patients with limited brain metastases. In this study, we evaluated the effectiveness of radiosurgery for brain metastases from unknown primary tumors. METHODS: We retrospectively evaluated 540 patients who underwent gamma knife radiosurgery (GKRS) for brain metastases radiologically diagnosed between August 1992 and September 2007 in our institution. First, the brain metastases were grouped into metachronous, synchronous, and precocious presentations according to the timing of diagnosis of the brain metastases. Then, synchronous and precocious brain metastases were further grouped into 1) unknown primary; 2) delayed known primary; and 3) synchronous metastases according to the timing of diagnosis of the primary origin. We analyzed the survival time and time to new brain metastasis in each group. RESULTS: Of the 540 patients, 29 (5.4%) presented precocious or synchronous metastases (34 GKRS procedures for 174 lesions). The primary tumor was not found even after intensive and repeated systemic evaluation in 10 patients (unknown primary, 34.5%); found after 8 months in 3 patients (delayed known primary, 1.2%); and diagnosed at the same time as the brain metastases in 16 patients (synchronous metastasis, 55.2%). No statistically significant differences in survival time and time to new brain metastasis were found among the three groups. CONCLUSION: Identification of a primary tumor before GKRS did not affect the patient outcomes. If other possible differential diagnoses were completely excluded, early GKRS can be an effective treatment option for brain metastases from unknown primary tumor.
Brain* ; Diagnosis ; Diagnosis, Differential ; Humans ; Incidence ; Neoplasm Metastasis* ; Neoplasms, Unknown Primary ; Radiosurgery* ; Retrospective Studies

The clinical appearance of metastatic lesions without an obvious primary source for the tumor is not uncommon event although modern diagnostic technology has improved. Metastatic neoplasms of unknown primary origin account for up to 2.1-11% of metastatic lesions in temporal bones. We recently experienced a case with metastatic adenocarcinoma of unknown primary origin involving the temporal bone. A 66-year-old woman was admitted to our hospital because of facial palsy and facial pain. She was diagnosed with metastatic adenocarcinoma in the temporal bone based on the pathologic findings but the primary origin was not found despite extensive diagnostic work-up for all suspicious sites. So we report this case with a review of related literatures.
Adenocarcinoma ; Aged ; Facial Pain ; Facial Paralysis ; Female ; Humans ; Neoplasm Metastasis ; Neoplasms, Unknown Primary ; Temporal Bone

Carcinoma of unknown primary (CUP) is a kind of metastatic tumor whose primary origin cannot be identified after adequate examination and evaluation. The main treatment modality of CUP is empiric chemotherapy, and the median overall survival time is less than 1 year. Compared with immunohistochemistry, novel method based on gene expression profiling have improved the sensitivity and specificity of CUP detection, but its guiding value for treatment is still controversial. The approval of immune checkpoint inhibitors and pan-cancer antitumor agents has improved the prognosis of patients with CUP, and targeted therapy and immunotherapy based on specific molecular characteristics are the main directions of future research. Given the high heterogeneity and unique clinicopathological characteristics of CUP, "basket trial" is more suitable for clinical trial design in CUP.
Humans ; Neoplasms, Unknown Primary/genetics* ; Carcinoma/drug therapy* ; Gene Expression Profiling/methods* ; Microarray Analysis ; Prognosis

Unknown primary tumor is not an unusual phenomenon. It has been reported that patients with primary unknown cancer constitute 0.5~3.3% of all cancer patients. The most common site of the detected cancer was the lymph node. The locations of the lymph node were cervical, supraclavicular, axillary and inguinal regions. Squamous cell carncer at a metastatic site is found in only approximately 5% of all patients with unknown primary tumors. Especially, squamous cell cancer detected only in mediastinal or hilar lymph nodes is quite rare. We report one case of Metastatic squamous cell cancer of the mediastinum with unknown primary tumor, in which a metastatic survey has not yieled any evidence of further disease. The pathologic finding was representative of squamous cell cancer. A chemotherapy was performed based on the advanced lung cancer for the treatment without surgical approach.
Carcinoma, Squamous Cell* ; Drug Therapy ; Humans ; Lung Neoplasms ; Lymph Nodes ; Mediastinum* ; Neoplasms, Squamous Cell ; Neoplasms, Unknown Primary*

Occult breast cancer is a type of breast cancer without any symptoms on the breasts or any abnormalities upon radiologic examination such as mammography. In males, there are few cases of breast cancer, the rate of diagnosis of occult breast cancer is very low, and little is known about this disease. We experienced two cases of occult breast cancers manifesting as axillary lymph node metastasis in men. They had a palpable lesion on axillary area several years ago and had not seen a doctor about it. As such there was no abnormality on evaluations for cancer except for axillary lymph node showing signs of carcinoma (primary or metastatic) on biopsy and estrogen receptor-positive and progesterone receptor-positive on immunohistochemistry. The patients were diagnosed with occult breast cancer, and treatments were performed. Herein, we report the rare cases of occult breast cancers in men.
Axilla ; Biopsy ; Breast ; Breast Neoplasms ; Estrogens ; Humans ; Immunohistochemistry ; Lymph Nodes ; Male ; Mammography ; Neoplasm Metastasis ; Neoplasms, Unknown Primary ; Progesterone

Intracranial neoplasms usually have definitive symptoms, causing a need for medical intervention, but a few cases result in sudden unexpected death even before diagnosis. In these cases, autopsy or post-mortem imaging may be the only way of identifying the existence of a tumor, so investigators or forensic specialists who participate in the post-mortem inspection should be aware of these possibilities. We report on a case of a 26-year-old woman without any medical history found dead in her home. A 5-cm intraventricular tumor was found during autopsy, which was histologically consistent with anaplastic ganglioglioma a very rare type of neuroglial tumor with the potential for malignant behavior. The tumor showed the characteristic features of anaplastic ganglioglioma, such as increased cellularity, a high Ki-67 proliferative index, and necrosis. There were signs of increased intracranial pressure, including flattened gyri and dilated ventricles, which led to the conclusion that this brain tumor was the cause of death.
Adult ; Autopsy ; Brain Neoplasms ; Cause of Death ; Diagnosis ; Female ; Ganglioglioma* ; Humans ; Intracranial Pressure ; Necrosis ; Neoplasms, Unknown Primary ; Research Personnel ; Specialization

The increased sensitivity of many imaging devices has increased the identification of asymptomatic nodules in the thyroid gland. In this study we investigated the actual incidence of nonpalpable thyroid nodules and occult carcinoma in women. Between January and June 2003, among the women who were scheduled to undergo breast ultrasonography, 697 without palpable thyroid nodules were screened for thyroid nodules. They were classified into four categories according to ultrasonographic findings: negative, benign, indeterminate and malignant. Ultrasound-guided fine-needle aspiration biopsy (FNAB) was carried out for all malignant lesions and for some of the benign and indeterminate ones. The nodule detection and malignancy rates were determined and the effectiveness of ultrasonography as a diagnostic tool was also investigated. Out of the 697 subjects, 246 (35.3%) were found to have thyroid nodules. The malignancy detection rate based on the FNAB results, including both suspicious and malignant groups, was 3.6% (25/697) for all subjects. In addition, 3.0% (21/697) of all the women were confirmed to have thyroid cancer by surgery. The sensitivity of sonographic classification was increased from 80% to 100% when the indeterminate class was added to the malignant one, although this decreased the specificity from 91.7% to 33.3%. In conclusion, high-resolution ultrasonography detected a high percentage of malignant nodules. Ultrasonography can augment its value by guiding FNAB, in addition to providing diagnostic images.
Adult ; Carcinoma/surgery/*ultrasonography ; Child ; Female ; Human ; Middle Aged ; Neoplasms, Unknown Primary/surgery/*ultrasonography ; Thyroid Neoplasms/surgery/*ultrasonography ; Thyroidectomy/methods

Malignant melanoma is the most common metastatic tumor of the gastrointestinal tract and can present with fairly common constitutional symptoms. A 36-yr-old woman was found to have a secondary malignant melanoma in the terminal ileum with profuse aneurysmal dilatation, which is not the typical presentation of the malignant melanoma in the small intestine. Radiologic studies revealed a large tumor involving the distal ileum with aneurysmal dilatations having afferent and efferent loops, which needed to be differentiated from malignant lymphoma and other gastrointestinal tumors. Exploratory laparotomy was done, and we found a huge mass with plentiful aneurysmal dilatations; much the same of the findings from the previous studies. Segmental resection with the surrounding omentum was done followed by end-to-end anastomosis between both ends of the remaining ileum. She had been free from any evidence of the local or systemic recurrence for one year after the completion of eighteen months of the subcutaneous interferon treatment; postoperatively however, the occurrence of metastatic mass at the right axilla rendered us from complete resection due to severe penetration into the vital nerves and vessels in the axilla.
Adult ; Dilatation, Pathologic ; Female ; Human ; Ileal Neoplasms/*secondary ; Ileum/*pathology ; Melanoma/*secondary ; Neoplasm Recurrence, Local/pathology ; Neoplasms, Unknown Primary/*pathology

Aged ; Brain Abscess ; etiology ; Brain Neoplasms ; complications ; secondary ; Carcinoma, Squamous Cell ; complications ; secondary ; Humans ; Male ; Neoplasms, Unknown Primary ; Parietal Lobe