Significance of psammoma bodies in serous cavity fluid

Malignant effusions secondary to metastatic thyroid carcinomas: A review of 15 cases

BACKGROUND

Malignant effusions secondary to thyroid carcinomas are rare, and publications on this topic are limited. This study presents a large cohort of thyroid carcinomas involving effusion cytology.

METHODS

A 20-year computerized search for fluid cytology diagnosed with thyroid malignancy was performed. The following data were collected: patients' demographics, clinical findings, and histologic diagnoses. The cytology slides and ancillary tests were reviewed.

RESULTS

Among 47,593 specimens, 15 thyroid carcinomas involving the pleural fluid from 11 patients were found. There were six males and five females with a mean age of 72 years. Ten patients with available follow-up died of their disease. Papillary thyroid carcinoma (PTC) was the only histologic type. Ten cytology cases were available for review. The cytologic findings common to all cases were nonspecific (clusters/three-dimensional architecture, enlarged irregular nuclei, and scant to abundant to vacuolated cytoplasm). The classic PTC features were not present in all cases (fine/powdery chromatin [80%], micronucleoli [70%], nuclear grooves [50%], papillary-like architecture [40%], psammoma bodies [40%], and pseudo-nuclear inclusions [20%; present on the cell block only]). In 11 of the 15 cases, the diagnosis was rendered with immunohistochemical stains performed on the cell block (paired box 8, thyroid transcription factor 1, and thyroglobulin). In four of the 15 cases, the cytologic diagnosis was made after a comparison with prior surgical pathology or fluid cytology.

CONCLUSIONS

PTC is the most common histologic type of thyroid malignancy involving pleural effusion. Because the cytologic findings are nonspecific and classic PTC features are not always present, the clinical history in conjunction with immunohistochemical stains is helpful in arriving at the correct diagnosis.

Serous cavity metastasis: Evaluation of unknown primary

Malignant effusions can occur in patients with neoplasia. Once a metastatic diagnosis is confirmed, the primary site of origin of malignancy needs to be ascertained. This task can be challenging without a prior history of malignancy. In some patients their effusion may be the initial presentation of an underlying malignancy. Metastases usually present with a dual population of mesothelial and malignant cells. Combining cytomorphologic examination with ancillary testing such as immunocytochemistry can help identify the origin of the foreign malignant cell population. Helpful architectural clues include a single cell pattern, solid cell ball pattern, single file arrangement, papillary formation, psammoma bodies and background mucin. Useful cellular features include the presence of signet ring cells, small cells, pleomorphic and multinucleated giant cells, squamous cells, spindle cells and pigmentation. Rarely, despite an extensive work-up the primary site of origin for a malignant effusion may remain unresolved. This review article will be incorporated finally as one of the chapters in CMAS (CytoJournal Monograph/Atlas Series) #2. It is modified slightly from the chapter by the initial authors in the first edition of Cytopathologic Diagnosis of Serous Fluids.

Remarkable Differences in Calcification between the Primary Tumor and Metastatic Lymph Nodes in a Patient with ALK-Positive Non-Small-Cell Lung Cancer

Calcified bilateral mediastinal lymph nodes are not common in malignant tumors. A 51-year-old woman presented to our hospital with a 20 mm nodule in the lower left lobe of the lung and extensive calcification in the bilateral mediastinal lymph nodes. Computed tomography indicated no calcification of the primary lesion. Immunohistochemical staining and fluorescent in situ hybridization detected an anaplastic lymphoma kinase (ALK) fusion. Treatment with alectinib, an ALK inhibitor, led to a significant reduction in tumor size and calcification in the lymph nodes. This case shows that different degrees of calcification can be associated with malignant tumors and may be reversible in some cases.

Approach to Diagnostic Cytopathology of Serous Effusions

Collection of most serous fluids from various effusions is a relatively simple procedure. Because of this, serous fluids are commonly submitted for pathologic examination including cytopathologic evaluation by various clinical institutions. As a consequence, even a general pathology laboratory which may not have expertise with highly trained cytopathologist would be confronted with serous fluids for cytologic evaluation.

However, cytopathologic evaluation of serous fluids is complex as compared to evaluation of fine needle aspiration cytology. This signifies the fact that all pathologists, irrespective of subspeciality cytopathology training and level of subspeciality expertise, should be conversant with the diagnostic challenges and pitfalls of effusion fluid cytology.

Although, majority of effusions are due to reactive and non-neoplastic etiologies, cancer is one of the causes of an effusion as a manifestation of advanced cancer. Detecting neoplastic cells in effusion specimens in most of clinical settings is related to the advanced status of the disease, which usually is equivalent to incurable stage. Thus, interpretation of cytopathology as positive for cancer cell is highly critical in planning the trajectory of the clinical management with an obvious negative impact of false positive interpretation.

Apart from cancer, effusions may be secondary to hemodynamic pathologies such as heart failure, hypoalbuminemia, cirrhosis etc. in addition to the different inflammatory conditions including parasitic infestations, bacterial, fungal, or viral infections, and other non-neoplastic etiologies including collagen diseases. Due to the cytomorphologic overlap of reactive mesothelial cells with malignant cells, general cytologic criteria for diagnosis of malignancy in single cells cannot be applied in most of the effusion specimens. This challenge is further amplified because of surface tension related phenomenon which ‘round up’ the cells after exfoliation in serous fluids. As a result, the native shapes of cancer cells cannot be a guiding feature. Thus the cytomorphologic features of cancer cells in serous fluids may not be same as seen in routine cytopathology of exfoliative, brushing, and fine-needle aspiration specimens.

The cancer cells may continue to proliferate after exfoliation in the nutrient rich effusion fluids and may form proliferation spheres. It is crucial to consider these factors when interpreting effusion cytology. Amongst malignant effusions, adenocarcinomas are the most common cause of metastatic cancers, but almost any type of malignancy including melanomas, hematopoietic neoplasms, sarcomas, and mesotheliomas may involve serous cavities. The interpreter must be aware of the wide range of the cytomorphologic appearances of reactive mesothelial cells in effusion fluids. It is essential to understand these and other nuances related to effusion fluid cytology. Understanding potential pitfalls during various stages from processing to application of ancillary studies would increase the diagnostic accuracy and minimize atypical interpretations and false positivity.

Diagnostic pitfalls in effusion fluid cytology

Effusion fluid cytology has propensity for both false positives (in up to 0.5%) and false negatives (in up to 30%) results. Methodical approach from collection step to final interpretation stage could prevent both false positives and false negatives, if the interpreter is familiar with various factors responsible for diagnostic pitfalls in effusion fluid cytology. For this discussion, these factors are categorized as mentioned below: Surface tension-related alterations in cytomorphologyImproper specimen processingMany faces of reactive mesothelial cells, overlapping with those of cancer cellsProliferation-related featuresDegenerative changes, such as nuclear hyperchromasia and cytoplasmic vacuolationUnexpected patterns and unusual entities.

Introduction to the second edition of 'Diagnostic Cytopathology of Serous Fluids' as CytoJournal Monograph (CMAS) in Open Access

Serous fluids are excessive accumulation of fluids in a serous cavity as effusion. However, traditionally this area also covers cytopathologic evaluation of washings of these cavities including pelvic/peritoneal washing. This is the introductory review article in series on this topic with the application of simplified algorithmic approaches. The series would be compiled finally as a book after minor modifications of individual review articles to accommodate the book layout on the topic as second edition of 'Diagnostic Cytopathology of Serous Fluids' book. The approach is primarily directed towards detection of neoplastic cells based on morphology alone or with the help of various ancillary tests, including commonly applied immunocytochemistry to be interpreted as second foreign population with application of SCIP (subtractive coordinate immunoreactivity pattern) approach in effusion fluid tapings. As the role of molecular pathology tests is increasing, this component as ancillary testing will also be covered as applicable. Because a picture and sketches are worth a thousand words, illustrations and figures are included generously even at the risk of moderate repetition. The clinically important serous cavities include peritoneal cavity, pericardial cavity, and two pleural cavities. The primary topic of this series is specimens from these cavities as effusion fluids and washings including cytopathologic evaluation of peritoneal/pelvic washing. It is expected that some readers may not read the entire series or the final book from beginning to end, but refer to the individual review articles and chapters sporadically during their clinical practice. Considering this practical limitation, some brief repetition may be observed throughout the book. Some of the important themes will be highlighted as italicized and bolded text for quick reference. Dedicated articles/chapters are assigned for technical and other reference material as appendices. Tables, algorithms, sketches, and combination of pictures are included generously for quick reference. Most of the illustrations are attempted to be labeled appropriately with arrows and other indicators to avoid equivocation, especially for beginners in the field. This introductory review article describes general details under the following three broad headings: Histology and general cytology of serous cavity lining Effusion (general considerations) Ancillary techniques in brief.

Determining the significance of psammoma bodies in pelvic washings: A 10-year retrospective review

BACKGROUND

Pelvic washing specimens are relatively common and are submitted for patients undergoing gynecologic surgery to evaluate them for metastatic or occult disease. Psammoma bodies are a relatively uncommon finding in these specimens. To date, large-scale studies of their cytologic-histologic correlates and thus clinical significance have been limited.

METHODS

A 10-year retrospective search for all pelvic washing specimens was performed, and all cases were reviewed for the presence of psammoma bodies. The findings for the corresponding surgical pathology specimens were then catalogued.

RESULTS

Psammoma bodies were present in 138 cases (3.6% of 3840 total pelvic washings). More than half of the cases (n = 73 [53%]) were associated with benign processes, including mesothelial hyperplasia (n = 44), endosalpingiosis (n = 11), endometriosis (n = 11), and ovarian cystadenoma/cystadenofibroma (n = 7). Nineteen cases (14%) were associated with serous borderline tumors. Malignancies were noted in a third of the cases (n = 46 [33%]) and were most frequently low-grade serous adenocarcinomas (n = 15), high-grade serous adenocarcinomas (n = 11), or endometrioid endometrial carcinomas (n = 8). Patients found to have benign processes (median age, 50 years) or borderline disease (median age, 56 years) were significantly younger than patients with malignancies (median age, 65 years; P < .0001). In addition, the correlation of cytologic interpretation categories with concurrent histopathologic findings showed that cytologic analysis was highly sensitive and specific in determining the nature of underlying processes.

CONCLUSIONS

The majority of psammoma bodies noted in pelvic washings were associated with benign processes or borderline tumors, with approximately a third of the cases associated with malignancies. Psammoma bodies in pelvic washings from younger patients were significantly more likely to be associated with benign processes or borderline tumors.

Extensive calcification in adenocarcinoma of the lung: A case report

Calcification in lung nodules usually indicates a benign lesion. Here, we report the case of a 59‐year‐old male patient with a well defined 30 mm calcified nodule in his right upper lung lobe and calcified mediastinal lymph nodes. The mass was diagnosed as adenocarcinoma by transbronchial biopsy. He received systemic chemotherapy, followed by lobectomy and mediastinal lymph node dissection. During surgery, the lymph nodes were tightly adherent to the superior vena cava with invasion of the vascular wall. Pathological diagnosis confirmed acinar adenocarcinoma and psammoma bodies (PBs). Immunohistochemical analysis revealed tumor cells positive for parathyroid hormone‐related proteins 1 and 2. Calcification of primary lung adenocarcinoma is rare. We report a calcified lesion where the secretion of parathyroid hormone by the tumor may have caused the accumulation of PBs. Calcification of metastatic lymph nodes may increase the risk of adhesion, requiring care during surgery.

Key points

Significant findings of the study

Lung adenocarcinoma with extensive calcification in primary and metastatic lymph node lesions is rare and the mechanism involved is poorly understood. Of significance, calcification in our case was related to parathyroid hormone‐related proteins 1 and 2 secreted by the tumor.

What this study adds

This study suggests the potential role of parathyroid hormone‐related proteins in lung tumor calcification. The implications for clinicians are that calcified metastatic lymph nodes and tumors might be tightly fused to tissues. Therefore, surgery should be conducted with care.

Pleural fluid due to papillary thyroid cancer

We report herein a rare case of massive pleural effusion caused by papillary thyroid cancer, which was accompanied by multiple pulmonary metastasis. A 91-year-old male patient presented with shortness of breath due to massive right pleural fluid. Cytological specimens, which were obtained from pleural fluid by thoracentesis, and was consistent with that observed in surgically resected thyroid cancer 6-year previously. Immunocytochemical staining of the cells was positive for cytokeratin (CK)-7, CK-19, and positive for thyroglobulin. Massive pleural fluid due to a metastatic from papillary thyroid cancer is very rare but may develop in long-term survivors with this disease as observed in this case.

Cardiac tamponade as an initial presentation of papillary carcinoma with psammoma bodies and intranuclear grooves-A diagnostic dilemma

Involvement of body fluids by adenocarcinoma is a common phenomenon. However, metastasis to the pericardial fluid by adenocarcinoma is a rare occurrence. The most common malignancies associated with malignant pericardial effusion are carcinoma of the lung, breast, esophagus, melanoma, lymphoma, and leukemia. Here, we discuss a case of a 36-year-old female with hemorrhagic pericardial effusion presenting with cardiac tamponade and psammoma bodies which was suspected and reported as metastatic papillary carcinoma of thyroid on cytomorphology; however, the immunocytochemical and radiological features confirmed metastatic papillary adenocarcinoma of lung contrary to the thyroid which is more common and expected.

Role of Ancillary Techniques in Fluid Cytology

The cytologic evaluation of serous effusions may be challenging for a number of reasons. Distinction of benign, reactive conditions from malignancy represents the main focus when examining these specimens. The morphologic diagnosis of malignancy may be difficult due to the relative paucity of abnormal cells. In other situations, cellularity is not an issue, but the ability to confidently identify a second, foreign (i.e., tumor) population within a background mesothelial cells on the basis of cytomorphologic features alone may pose problems. Cases with definitive morphologic evidence of malignancy may require additional studies in order to determine the tumor subtype and, in the case of carcinoma, the primary site of origin. Cases in which a definitive and precise diagnosis of malignancy is made may be optimal candidates for further molecular testing in order to gain prognostic information and guide personal therapeutic decisions. Finally, while an inflammatory or infectious condition can be suggested on the basis of cellular components and associated background elements, the identification of causative agent(s) may be difficult without additional studies. In all of these situations, the use of ancillary studies and techniques is critical; their utility and appropriate application are the subject of this review.

Retroperitoneal low grade endometrial stromal sarcoma with florid endometrioid glandular differentiation: Cytologic-histologic correlation and differential diagnosis

Low grade endometrial stromal sarcoma (LGESS) is a rare neoplasm that typically arises in the uterine corpus and accounts for less than 1% of uterine sarcomas. Infrequently, extra-uterine LGESS can occur. Histologically, LGESS is characterized by a monotonous population of cells that resemble the proliferative phase of endometrial stroma and in their classic form they exhibit tongue-like growth pattern of infiltration and/or lymphovascular invasion. Infrequently LGESS can demonstrate various morphologic differentiation patterns, including endometrioid-type glands. We report the first fine needle aspiration (FNA) case of a periduodenal mass that was incidentally discovered on Computed Tomography (CT) scan of a 60-year-old female. The cytomorphologic and histologic findings and the immunohistochemical staining were consistent with a LGESS with endometrioid glandular differentiation. We are presenting the correlation between the cytologic, radiologic and pathologic features.

Widespread Psammoma Body Formation Arising in the Background of a Uterine Serous Carcinoma

This report highlights a very rare phenomenon of widespread psammomatous calcification without accompanying epithelium, present in the background of a uterine serous carcinoma. Psammomatous calcification is associated with benign and malignant pathology in different organ systems including the gynaecological tract.

Functional characterization of SAMD9, a protein deficient in normophosphatemic familial tumoral calcinosis

Dystrophic cutaneous calcinosis is associated with disorders as common as autoimmune diseases and cancer. To get insight into the pathogenesis of this poorly understood process, we studied the function of SAMD9, a protein of unknown function, recently shown to be deficient in a hereditary form of dystrophic calcification in the skin, known as normophosphatemic familial tumoral calcinosis (NFTC). Consistent with the fact that in NFTC severe inflammatory manifestations always precede cutaneous calcinosis, we found out that SAMD9 is tightly regulated by interferon-γ (IFN-γ). In addition, the SAMD9 promoter was also found to respond strongly to IFN-γ in a luciferase reporter assay. Of interest, we identified a critical 30-bp fragment upstream to the SAMD9 transcription initiation site responsible for driving most of the gene expression. Bioinformatic analysis suggested that SAMD9 function involves interaction with additional protein(s). Using the Ras recruitment system assay and confirmatory immunoprecipitation, we demonstrated that SAMD9 interacts with RGL2. To study the biological importance of this interaction, we assessed the effect of RNA interference-mediated downregulation of this pair of proteins in various cell lines. We found out that downregulation of any of the two protein partners caused increased expression of EGR1, a transcription factor with a known role in the regulation of tissue calcification, inflammation, and cell migration. Supporting the physiological relevance of these data, EGR1 levels were also upregulated in a fibroblast cell line derived from an NFTC patient. In conclusion, our data indicate that SAMD9, an IFN-γ-responsive protein, interacts with RGL2 to diminish the expression of EGR1, a protein of direct relevance to the pathogenesis of ectopic calcification and inflammation.

Psammoma body: a product of dystrophic calcification or of a biologically active process that aims at limiting the growth and spread of tumor?

Psammoma bodies (PBs) are concentric lamellated calcified structures, observed most commonly in papillary thyroid carcinoma (PTC), meningioma, and papillary serous cystadenocarcinoma of ovary but have rarely been reported in other neoplasms and nonneoplastic lesions. PBs are said to represent a process of dystrophic calcification. Despite numerous ancillary studies over a span of three and half decades, formation of PBs remains a poorly understood mechanism. Ultrastructural study of PTC has shown that thickening of the base lamina in vascular stalk of neoplastic papillae followed by thrombosis, calcification, and tumor cell necrosis leads to formation of PBs. Studies on serous cystadenocarcinoma of ovary and meningioma, however, revealed that collagen production by neoplastic cells and subsequent calcification was responsible for the formation of PBs. The existence of some precursor forms of PBs was reported in meningiomas and more recently in PTC, which were mostly in the form of extracellular hyaline globules surrounded by well-preserved neoplastic cells or in a smaller number of cases intracytoplasmic bodies liberated from intact tumor cells. Cellular degeneration and necrosis, leading to the disappearance of neoplastic cells, were noticed by us only around PBs but not around the precursor forms. Based on the above findings, it is suggested that rather than being the outcome of dystrophic calcification of dead or dying tissue, PBs may indeed represent an active biologic process ultimately leading to degeneration/death of tumor cells and retardation of growth of the neoplasm. It may also serve as a barrier against the spread of neoplasm.

Mesothelial pelvic lymph node inclusion in a patient with ovarian microinvasive borderline mucinous tumor: case report with review of the literature

The presence of mesothelial cell inclusions in lymph nodes is rare. Localization of these inclusions in abdominal and pelvic lymph nodes is an exceedingly rare event, with only eight cases reported. We report here a case of mesothelial cell inclusions in pelvic lymph node of a patient with ovarian microinvasive borderline mucinous tumor. This case differs from the previously reported cases for the following reasons. First, there was no evidence of serosal effusion. Second, it is the first reported case of nodal mesothelial inclusions in a patient with ovarian microinvasive mucinous borderline tumor. Last, histologically, mesothelial cell inclusions were accompanied by psammoma bodies. The potential problem of misdiagnosis as a metastatic tumor can be avoided by an awareness of these inclusions, supported by immunohistochemical results.