Diagnosis of metastatic neoplasms: an immunohistochemical approach

Case report: Unusual breast cancer metastasis manifesting as a scalp lesion in a patient with invasive lobular carcinoma

Breast cancer is the most prevalent cancer in women globally, often leading to distant metastasis in the lung, liver, or bones. Cutaneous metastasis represents an uncommon pattern in breast cancer, but when observed, it tends to manifest in the thorax and upper abdomen, primarily due to lymph node involvement. Therefore, occurrences of cutaneous metastasis on the scalp and extremities are infrequent. Moreover, invasive lobular carcinoma metastasizing to remote skin is rare among the breast cancer. This report presents a case of cutaneous metastasis of invasive lobular carcinoma to the scalp in a patient treated for breast cancer six years ago, with no signs of local recurrence or metastasis to other organs.

Breast cancer with scalp metastases: a case report

BACKGROUND

While breast cancer is the most common cancer in women, cutaneous metastases are rare in breast cancer. Additionally, scalp involvement in breast cancer metastasis is extremely rare. That being said, scalp lesions should always be thoroughly investigated to distinguish metastatic lesions from other neoplasms.

CASE PRESENTATION

A 47-year-old female Middle-Eastern patient presented with metastatic breast cancer in the lungs, bone, liver, and brain with no signs of multiple organ failure, in addition to cutaneous metastases, including the scalp. Between 2017 and 2022, she was managed through modified radical mastectomy, radiotherapy, and several lines of chemotherapy. She presented in September of 2022 with enlarging scalp nodules, which started developing 2 months prior to her presentation. Physical examination revealed firm, non-tender, and immobile skin lesions. Magnetic resonance imaging scan of the head showed soft tissue nodules in different sequences. A punch biopsy was taken from the largest scalp lesion and showed metastatic invasive ductal carcinoma. A panel of immunohistochemistry stains was applied, because a single specific marker for differentiating primary cutaneous adnexal tumors or other malignant neoplasms from breast cancer has not yet been identified. The panel showed positive estrogen receptor 95%, progesterone receptor 5%, negative human epidermal growth factor receptor 2, positive GATA binding protein 3, positive cytokeratin-7, negative P63, and negative KIT (CD117).

CONCLUSION

Breast cancer metastases to the scalp are extremely uncommon. When a scalp metastasis is present, it might be the only symptomatic sign of disease progression or widespread metastatic lesions. However, such lesions warrant a comprehensive radiologic and pathologic workup to rule out other possibilities of skin pathologies, such as sebaceous skin adenocarcinoma as it effects the management plan.

Metastasis of malignant pleural mesothelioma to the scalp following chemotherapy: A case report and review of the literature

Malignant pleural mesothelioma is a neoplasm involving mesothelial cells of the pleura. Both local and distant metastases may develop, although the latter are less common and it is extremely rare for cutaneous metastases to appear as a solitary lesion on the scalp. We present the case of a 54-year-old woman with a 2-year history of unresectable left pleural mesothelioma treated with chemotherapy, who had developed a painful lump on the scalp one month prior to consultation. Skin metastases of mesothelioma must be differentiated from primary neoplasms, and immunohistochemistry is fundamental to determine the origin of such lesions, which can be correctly identified through the use of a panel of markers.

Myeloid Sarcoma Expressing Keratins and Mimicking Carcinoma-Case Report and Literature Review

Unusual presentations of otherwise common hematopoietic neoplasms are a well-recognized diagnostic challenge. Herein, we present a case study of a previously healthy 64 year old woman with myeloid sarcoma whose diagnosis was delayed by an unusual immunohistochemical staining pattern, including cytokeratin expression, by the neoplastic cells and by possible anchoring bias introduced by radiographic and flow cytometric immunophenotyping reports. This case study emphasizes the need to integrate clinical, radiographic, histologic, and immunophenotyping data for rapid and accurate tissue diagnoses while being wary of the lack of specificity for many common immunophenotypic markers.

Primary Small Cell Carcinoma of the Bladder

A 64-year-old Caucasian man with a 20 to 25-pack-year cigarette smoking history presented to his primary care provider with the chief complaint of gross hematuria after experiencing three to four months of urinary frequency and urgency. His workup consisted of laboratory blood work, a renal/bladder ultrasound (US), a CT scan without contrast, cystoscopy with biopsy (with an attempted transurethral resection of bladder tumor), and a PET scan. He was diagnosed with stage T4 small cell carcinoma of the bladder (SCCB) shortly after seeking medical care with metastases to the liver, bone, and lymph nodes. There was no evidence of lung involvement. The patient's primary concerns included difficulty urinating and sustained hematuria. He underwent palliative radiotherapy and placement of bilateral nephrostomy tubes in order to preserve his quality of life. He also received a chemotherapy regimen consisting of cisplatin, etoposide, and atezolizumab. The patient underwent hospice care and died approximately six months after the presentation.

Multiplex Immunofluorescence Tyramide Signal Amplification for Immune Cell Profiling of Paraffin-Embedded Tumor Tissues

Every day, more evidence is revealed regarding the importance of the relationship between the response to cancer immunotherapy and the cancer immune microenvironment. It is well established that a profound characterization of the immune microenvironment is needed to identify prognostic and predictive immune biomarkers. To this end, we find phenotyping cells by multiplex immunofluorescence (mIF) a powerful and useful tool to identify cell types in biopsy specimens. Here, we describe the use of mIF tyramide signal amplification for labeling up to eight markers on a single slide of formalin-fixed, paraffin-embedded tumor tissue to phenotype immune cells in tumor tissues. Different panels show different markers, and the different panels can be used to characterize immune cells and relevant checkpoint proteins. The panel design depends on the research hypothesis, the cell population of interest, or the treatment under investigation. To phenotype the cells, image analysis software is used to identify individual marker expression or specific co-expression markers, which can differentiate already selected phenotypes. The individual-markers approach identifies a broad number of cell phenotypes, including rare cells, which may be helpful in a tumor microenvironment study. To accurately interpret results, it is important to recognize which receptors are expressed on different cell types and their typical location (i.e., nuclear, membrane, and/or cytoplasm). Furthermore, the amplification system of mIF may allow us to see weak marker signals, such as programmed cell death ligand 1, more easily than they are seen with single-marker immunohistochemistry (IHC) labeling. Finally, mIF technologies are promising resources for discovery of novel cancer immunotherapies and related biomarkers. In contrast with conventional IHC, which permits only the labeling of one single marker per tissue sample, mIF can detect multiple markers from a single tissue sample, and at the same time, deliver extensive information about the cell phenotypes composition and their spatial localization. In this matter, the phenotyping process is critical and must be done accurately by a highly trained personal with knowledge of immune cell protein expression and tumor pathology.

Eyelid metastasis from lung adenocarcinoma

Purpose

To report an unusual case of lung metastasis presenting as an eyelid lesion.

Observations

An 82-year-old man presented with a right upper lid lesion of 2 weeks' duration proven to be adenocarcinoma of the lung.

Conclusions and importance

Metastasis to the eyelid is a rare occurrence. We present a review of the literature emphasizing factors contributing to its low incidence.

Metastatic breast cancer presenting as acute liver injury: diagnostic dilemma in the setting of suspected hemochromatosis

A 70-year-old female with a history of lobular carcinoma of the breast, status post-mastectomy followed by adjuvant radio-chemotherapy in remission for 4 years was admitted with the features of acute liver failure (ALF). Iron studies revealed a hemochromatosis picture and the CT and MRI scans of the abdomen suggested cirrhosis. An extensive workup failed to identify an etiology. A trans-jugular liver biopsy was obtained and revealed poorly differentiated carcinoma consistent with the metastasis of breast primary. The patient’s condition deteriorated and died within a week following the onset of acute hepatic failure. DNA testing revealed that the patient was heterozygous for H63D mutation. In cases of ALF with the suspicion of malignancy, liver biopsy should be obtained to evaluate an infiltrative hepatic disease.

Leptomeningeal Carcinomatosis From Carcinoma of Unknown Primary in a Young Patient: A Case Report and a Literature Review

Leptomeningeal carcinomatosis, leptomeningeal meningitis, or, as referred here, leptomeningeal metastasis (LM), is a rare but frequently fatal complication seen in advanced stage of cancer either locally advanced or after a metastasis of a known primary cancer. We present a rare and uncommon case of leptomeningeal metastases from carcinoma of unknown primary. A 32-year-old female was diagnosed with LM; however, no known primary carcinoma was identified after 2 separate biopsies. The first biopsy of the right pre-tracheal lymph node showed poorly differentiated pan-keratin (AE1 and AE3) and placental alkaline phosphatase with the possibility of germ cell origin. Second cytology of cervical lymphadenopathy was remarkable for cytokeratin 7 and 20, placental alkaline phosphatase, and CDX2 suggestive of germ line tumor with both mucinous ovarian and gastrointestinal carcinomas. Unfortunately, the LM progressed rapidly despite multiple cycles of germ cell origin directed systemic and intrathecal chemotherapy, and the patient opted for hospice care without getting a chance to identify the primary source.

Metastatic disease masquerading as small intestinal tumoural masses: two case reports and literature review

Metastatic disease presenting clinically as small intestinal tumoural masses has been described in the literature but is uncommon. It is imperative to consider the possibility of metastases before diagnosing a primary small intestinal malignancy. We hereby illustrate two such case reports of metastatic disease presenting as tumoural masses in the small intestines. First is a 63-year-old gentleman with known metastatic renal cell carcinoma (RCC) who presented with intestinal obstruction. Radiological imaging of the abdomen revealed a jejuno-jejunal intussusception, secondary to a solitary polypoid tumour. Histology of the polypoid tumour confirmed the presence of clear cell RCC. In our literature review, we note that intussusception is a common presentation in metastatic RCC to the small intestines. Hence, this clinical feature may be useful in determining a metastatic process, even in the setting of a solitary lesion. Second is a 41-year-old lady who presented with massive bleeding from the upper gastrointestinal tract. Gross examination of the distal duodeno-jejunectomy specimen reveals aggregates of reddish polypoid tumours. Histological and immunohistochemical techniques culminated in a diagnosis of metastatic choriocarcinoma. Metastatic choriocarcinoma to the small intestines is uncommon, but careful evaluation of histological features coupled with the judicious use of immunohistochemistry and a degree of suspicion can help make the correct diagnosis. In conclusion, metastatic disease masquerading as small intestinal tumoural masses is not uncommon. Judicious use of immunohistochemistry, in addition to the careful identification of pertinent clinical and histological features, can help pathologists reach the correct diagnosis.

Interpretation of immunohistochemistry data of tumor should consider microenvironmental factors

The influence of tumor surrounding microenvironment is often neglected when immunohistochemistry is performed to investigate tumor properties and search biomarkers of cancer. This study was designed to evaluate whether the influence of tumor microenvironment on biological features of tumor cells should be taken into account for interpretation of the immunohistochemistry data of tumor specimens. In this study, we showed an example by using three tumor cell lines (HeLa, WSU-HN6, and Tca83) to establish tumor-caused bone destruction models in nude mice and then to investigate the influence of bone marrow microenvironment (BMM) on biological features of tumor cells. Immunohistochemistry results showed that, compared with tumor cells located outside of BMM, tumor cells located inside of BMM presented huge differences in the expression of inflammation-related proteins including tumor necrosis factor-α (TNF-α), TNF receptor-associated factor protein-6 (TRAF-6), phosphorylated-NF-κB p65 (p-p65), interleukin (IL)-6 and IL-11, matrix metalloproteinases including MMP-1, MMP-2, MMP-9, and MMP-13; and osteogenesis-related proteins including runt-related transcription factor 2 (RUNX2), bone sialoprotein (BSP), and osteocalcin (OCN) in all the models. However, when we compared the cell line pair derived from different sites (outside and inside of BMM, respectively) of the same HeLa tumor sample by real-time PCR, Western blot, and immunocytochemistry, the differences aforementioned in tumor tissues were not found. In addition, we verified that normal human bone marrow could not cause the above changes detected in vivo. Our results suggested that tumor-modified microenvironment could give the new biological features of the invaded tumor cells. Therefore, we should consider the influence of the surrounding microenvironment on tumor cells when we analyze tumor properties using immunohistochemistry.

Immunohistochemistry in undifferentiated neoplasm/tumor of uncertain origin

CONTEXT

Immunohistochemistry has become an indispensable ancillary study in the identification and classification of undifferentiated neoplasms/tumors of uncertain origin. The diagnostic accuracy has significantly improved because of the continuous discoveries of tissue-specific biomarkers and the development of effective immunohistochemical panels.

OBJECTIVES

To identify and classify undifferentiated neoplasms/tumors of uncertain origin by immunohistochemistry.

DATA SOURCES

Literature review and authors' research data and personal practice experience were used.

CONCLUSIONS

To better guide therapeutic decisions and predict prognostic outcomes, it is crucial to differentiate the specific lineage of an undifferentiated neoplasm. Application of appropriate immunohistochemical panels enables the accurate classification of most undifferentiated neoplasms. Knowing the utilities and pitfalls of each tissue-specific biomarker is essential for avoiding potential diagnostic errors because an absolutely tissue-specific biomarker is exceptionally rare. We review frequently used tissue-specific biomarkers, provide effective panels, and recommend diagnostic algorithms as a standard approach to undifferentiated neoplasms.

Metastatic tumors to the jaws and oral cavity

Cancer is a disease involving complex multiple sequential irreversible dysregulated processes showing metastasis that results in morbidity and mortality. Metastasis is a complex biological course that begins with detachment of tumor cells from the primary tumor, spreading into the distant tissues and/or organs, invading through the lymphovascular structures followed by their survival in the circulation. Metastatic tumors to the oro-facial region are uncommon and may occur in the oral soft tissues or jawbones. The clinical presentation of metastatic tumors can be variable, which may lead to erroneous diagnosis or may create diagnostic dilemma. Therefore, they should be considered in the differential diagnosis of inflammatory and reactive lesions that are common to the oral region. Most of the literature on oral metastases involves either single case reports or reviews of these reported cases from scattered geographical areas. Hence this present article is an attempt to provide a detailed review of pathogenesis, epidemiological details including clinical and radiographic presentations, microscopic features and treatment of metastatic tumors to the jaws and oral cavity.

Metastatic tumors to the jaws and oral cavity

Cancer is a disease involving complex multiple sequential irreversible dysregulated processes showing metastasis that results in morbidity and mortality. Metastasis is a complex biological course that begins with detachment of tumor cells from the primary tumor, spreading into the distant tissues and/or organs, invading through the lymphovascular structures followed by their survival in the circulation. Metastatic tumors to the oro-facial region are uncommon and may occur in the oral soft tissues or jawbones. The clinical presentation of metastatic tumors can be variable, which may lead to erroneous diagnosis or may create diagnostic dilemma. Therefore, they should be considered in the differential diagnosis of inflammatory and reactive lesions that are common to the oral region. Most of the literature on oral metastases involves either single case reports or reviews of these reported cases from scattered geographical areas. Hence this present article is an attempt to provide a detailed review of pathogenesis, epidemiological details including clinical and radiographic presentations, microscopic features and treatment of metastatic tumors to the jaws and oral cavity.

Diagnostic Approach to Hepatic Mass Lesions and Role of Immunohistochemistry

This review provides an overview of various hepatic mass lesions and a practical diagnostic approach, including most recent immunohistochemical stains used in clinical practice. A wide variety of benign and malignant lesions present as hepatic masses, and the differential diagnosis varies. In cirrhotic liver, the commonest malignant tumor is hepatocellular carcinoma (HCC), which needs to be differentiated from macroregenerative nodules, dysplastic nodules, and other tumors. The differential diagnosis of lesions in noncirrhotic liver in younger patients includes hepatic adenoma (HA), focal nodular hyperplasia (FNH), HCC, and other primary hepatic neoplasms and metastases. In older populations, metastases remain the most common mass lesions.

Metastatic tumors to the gingiva and the presence of teeth as a contributing factor: a literature analysis

BACKGROUND

Gingiva that is prone to inflammation may serve as a pre-metastatic niche for the attraction of circulating malignant cells. The aim of this study is to analyze cases of metastatic lesions to the gingiva compared with cases metastasizing to other oral mucosal sites. The pathogenesis of gingival metastases is discussed, with emphasis on the role of inflammation.

METHODS

The English-language literature between 1916 and 2011 was searched for cases of metastatic lesions to the oral mucosa; only cases metastasizing in the oral mucosa, gingiva, and periodontium were included.

RESULTS

Two hundred seven cases were included. The gingiva was the most common site (60.4%), followed by tongue and tonsil. The most common primary sites were lung (24.2%), kidney (13.5%), skin (10.6%), and breast (8.7%). In 27%, the oral lesion was the first sign of a malignant disease. In most cases, the lesion appeared as an exophytic mass (96%) diagnosed clinically as a reactive gingival lesion. The presence of teeth was significantly associated with the development of gingival metastases: in 108 of 125 gingival metastases, the lesion was found adjacent to teeth (P <0.001; odds ratio = 8.2). The average life expectancy after diagnosis of the metastasis was 3.7 months.

CONCLUSIONS

The gingiva is the most common site for metastases to oral soft tissues, with strong association with the presence of teeth. This finding may be related to the role of inflammation in the attraction of metastatic cells to chronically inflamed gingiva.

Comparison of histopathology to gene expression profiling for the diagnosis of metastatic cancer

Background

Determining the primary site of metastatic cancer with confidence can be challenging. Pathologists commonly use a battery of immunohistochemical (IHC) stains to determine the primary site. Gene expression profiling (GEP) has found increasing use, particularly in the most difficult cases. In this pilot study, a direct comparison between GEP and IHC-guided methods was performed.

Methods

Ten archived formalin-fixed paraffin embedded metastatic tumor samples for which the primary site had been clinically determined were selected. Five pathologists who were blinded to the diagnosis were asked to determine the primary site using IHC and other stains selected from a panel of 84 stains. Each pathologist was provided patient sex, biopsy site and gross sample description only. Slides were digitized using ScanScope®XT at 0.25 μm/pixel. Each evaluating pathologist was allowed to provide a diagnosis in three stages: initial (after reviewing the H&E image), intermediate (after reviewing images from the first batch of stains) and final diagnosis (after the second batch of stains if requested). GEP was performed using the only FDA-cleared test for this intended use, the Pathwork Tissue of Origin Test. No sample information was provided for GEP testing except for patient sex. Results were reported as the tumor tissue type with the highest similarity score.

Results

In this feasibility study, GEP determined the correct primary site in 9 of the 10 cases (90%), compared to the IHC-guided method which determined the correct primary site for 32 of 50 case evaluations (average 64%, range 50% to 80%). The five pathologists directing the IHC-guided method ordered an average of 8.8 stains per case (range 1 to 18). GEP required an average of 3 slides per case (range 1 to 4).

Conclusions

Results of the pilot study suggest that GEP provides correct primary site identification in a higher percentage of metastatic cases than IHC-guided methods, and uses less tissue. A larger comparative effectiveness study using this study design is needed to confirm the results.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1749854104745508

A second-generation microRNA-based assay for diagnosing tumor tissue origin

BACKGROUND

Cancers of unknown primary origin (CUP) constitute 3%-5% (50,000 to 70,000 cases) of all newly diagnosed cancers per year in the United States. Including cancers of uncertain primary origin, the total number increases to 12%-15% (180,000 to 220,000 cases) of all newly diagnosed cancers per year in the United States. Cancers of unknown/uncertain primary origins present major diagnostic and clinical challenges because the tumor tissue of origin is crucial for selecting optimal treatment. MicroRNAs are a family of noncoding, regulatory RNA genes involved in carcinogenesis. MicroRNAs that are highly stable in clinical samples and tissue specific serve as ideal biomarkers for cancer diagnosis. Our first-generation assay identified the tumor of origin based on 48 microRNAs measured on a quantitative real-time polymerase chain reaction platform and differentiated 25 tumor types.

METHODS

We present here the development and validation of a second-generation assay that identifies 42 tumor types using a custom microarray. A combination of a binary decision-tree and a k-nearest-neighbor classifier was developed to identify the tumor of origin based on the expression of 64 microRNAs.

RESULTS

Overall assay sensitivity (positive agreement), measured blindly on a validation set of 509 independent samples, was 85%. The sensitivity reached 90% for cases in which the assay reported a single answer (>80% of cases). A clinical validation study on 52 true CUP patients showed 88% concordance with the clinicopathological evaluation of the patients.

CONCLUSION

The abilities of the assay to identify 42 tumor types with high accuracy and to maintain the same performance in samples from patients clinically diagnosed with CUP promise improved utility in the diagnosis of cancers of unknown/uncertain primary origins.

Prospective gene signature study using microRNA to identify the tissue of origin in patients with carcinoma of unknown primary

PURPOSE

Accurate identification of tissue of origin (ToO) for patients with carcinoma of unknown primary (CUP) may help customize therapy to the putative primary and thereby improve the clinical outcome. We prospectively studied the performance of a microRNA-based assay to identify the ToO in CUP patients.

EXPERIMENTAL DESIGN

Formalin-fixed paraffin-embedded (FFPE) metastatic tissue from 104 patients was reviewed and 87 of these contained sufficient tumor for testing. The assay quantitates 48 microRNAs and assigns one of 25 tumor diagnoses by using a biologically motivated binary decision tree and a K-nearest neighbors (KNN). The assay predictions were compared with clinicopathologic features and, where suitable, to therapeutic response.

RESULTS

Seventy-four of the 87 cases were processed successfully. The assay result was consistent or compatible with the clinicopathologic features in 84% of cases processed successfully (71% of all samples attempted). In 65 patients, pathology and immunohistochemistry (IHC) suggested a diagnosis or (more often) a differential diagnosis. Out of those, the assay was consistent or compatible with the clinicopathologic presentation in 55 (85%) cases. Of the 9 patients with noncontributory IHC, the assay provided a ToO prediction that was compatible with the clinical presentation in 7 cases.

CONCLUSIONS

In this prospective study, the microRNA diagnosis was compatible with the clinicopathologic picture in the majority of cases. Comparative effectiveness research trials evaluating the added benefit of molecular profiling in appropriate CUP subsets are warranted. MicroRNA profiling may be particularly helpful in patients in whom the IHC profile of the metastasis is nondiagnostic or leaves a large differential diagnosis.