Carcinoma Cuniculatum: A Rare Malignancy With Unique Diagnostic Dilemmas

Carcinoma cuniculatum is an extremely rare and often indolent cancer that can mimic a benign process, such as osteomyelitis or odontogenic infections. This results in a definitive diagnosis that is delayed. To complicate the evaluation of this uncommon neoplasm, biopsies are often misinterpreted secondary to an incorrectly obtained tissue sample. Incisional biopsy needs to be done in a specific manner with a high degree of clinical suspicion incorporated into the patient assessment for the most accurate diagnosis. Local and distant failure rates are low with aggressive surgical resection and surgery upfront remains the treatment of choice when feasible. We present two cases that highlight the difficulty in accurate diagnosis and management of these rare cancers.

Successful treatment of a keratoacanthoma in a young patient with the application of topical 5% imiquimod cream

Keratoacanthomas (KA) are epithelial tumors that present as rapidly evolving nodules with a central hyperkeratotic plug and occasionally show signs of spontaneous regression. A 21-year-old patient strongly refused the diagnostic biopsy and insisted on a nonsurgical treatment. He was successfully treated with imiquimod 5% cream.

High-grade serous ovarian tumor cells modulate NK cell function to create an immune-tolerant microenvironment

Tubo-ovarian high-grade serous carcinoma (HGSC) is unresponsive to immune checkpoint blockade despite significant frequencies of exhausted T cells. Here we apply mass cytometry and uncover decidual-like natural killer (dl-NK) cell subpopulations (CD56+CD9+CXCR3+KIR+CD3-CD16-) in newly diagnosed HGSC samples that correlate with both tumor and transitioning epithelial-mesenchymal cell abundance. We show different combinatorial expression patterns of ligands for activating and inhibitory NK receptors within three HGSC tumor compartments: epithelial (E), transitioning epithelial-mesenchymal (EV), and mesenchymal (vimentin expressing [V]), with a more inhibitory ligand phenotype in V cells. In cocultures, NK-92 natural killer cells acquire CD9 from HGSC tumor cells by trogocytosis, resulting in reduced anti-tumor cytokine production and cytotoxicity. Cytotoxicity in these cocultures is restored with a CD9-blocking antibody or CD9 CRISPR knockout, thereby identifying mechanisms of immune suppression in HGSC. CD9 is widely expressed in HGSC tumors and so represents an important new therapeutic target with immediate relevance for NK immunotherapy.

Solid Pseudopapillary Neoplasm of the Uncinate Process of the Pancreas: A Case Report and Review of the Literature

Solid pseudopapillary neoplasm (SPN) is a rare pancreatic neoplasm that accounts for 1-3% of all pancreatic tumors. SPNs are most commonly found in females in their third and fourth decades of life. Even though the majority of the tumors are benign, malignant tumors have also been reported. Given its rare occurrence, it remains a clinical dilemma in gastroenterology, oncology, and pathology. It is critical to diagnose it early and differentiate it from other similar pancreatic tumors or cysts to ensure favorable patient outcomes. Advanced imaging techniques, characteristic histologic findings, and immunohistochemical analysis can help in diagnosing solid pseudopapillary tumors. Early diagnosis and surgical resection can result in a cure in most cases, and tumor recurrence is extremely rare. In this report, we present a case of a 40-year-old female patient who presented to the emergency room and was diagnosed with SPN of the pancreas.

Big Insulin-like Growth Factor 2-Producing Tumor in a Hypoglycemic Dog

A 10-year-old female Papillon dog that had previously developed a mammary tumor was admitted for treatment of a hypoglycemic attack. Blood examination showed severe hypoglycemia and decreased blood insulin concentration. Computed tomography indicated multiple tumors in the cranial and caudal lobes of the right lung. These tumors were resected surgically and diagnosed as pulmonary adenocarcinomas by histopathologic examination. Hypoglycemia was temporarily improved after the resection, but a hypoglycemic event occurred 2 months after the surgery. Immunohistochemistry of the tumor demonstrated the expression of insulin-like growth factor 2 in tumor cells. Western blot analysis revealed the expression of high-molecular-weight (big)-insulin-like growth factor 2 in the tumor region. Insulin-like growth factor 2 mRNA expression was also confirmed in the tumor using reverse transcription-polymerase chain reaction. These findings indicate the diagnosis of non-islet cell tumor-induced hypoglycemia caused by big-insulin-like growth factor 2 produced by the tumor in the dog. This report provides information on differentiating tumors that cause paraneoplastic hypoglycemia.

Development of Human Monoclonal Antibody for Claudin-3 Overexpressing Carcinoma Targeting

Most malignant tumors originate from epithelial tissues in which tight junctions mediate cell-cell interactions. Tight junction proteins, especially claudin-3 (CLDN3), are overexpressed in various cancers. Claudin-3 is exposed externally during tumorigenesis making it a potential biomarker and therapeutic target. However, the development of antibodies against specific CLDN proteins is difficult, because CLDNs are four-transmembrane domain proteins with high homology among CLDN family members and species. Here, we developed a human IgG1 monoclonal antibody (h4G3) against CLDN3 through scFv phage display using CLDN3-overexpressing stable cells and CLDN3-embedded lipoparticles as antigens. The h4G3 recognized the native conformation of human and mouse CLDN3 without cross-reactivity to other CLDNs. The binding kinetics of h4G3 demonstrated a sub-nanomolar affinity for CLDN3 expressed on the cell surface. The h4G3 showed antibody-dependent cellular cytotoxicity (ADCC) according to CLDN3 expression levels in various cancer cells by the activation of FcγRIIIa (CD16a). The biodistribution of h4G3 was analyzed by intravenous injection of fluorescence-conjugated h4G3 which showed that it localized to the tumor site in xenograft mice bearing CLDN3-expressing tumors. These results indicate that h4G3 recognizes CLDN3 specifically, suggesting its value for cancer diagnosis, antibody-drug conjugates, and potentially as a chimeric antigen receptor (CAR) for CLDN3-expressing pan-carcinoma.

Lacrimal gland tumors in Turkey: types, frequency, and outcomes

AIM

To evaluate the clinical, radiological, and treatment features of lacrimal gland tumors.

METHODS

Retrospective review of 99 eyes of 92 patients with lacrimal gland tumors diagnosed and managed in a single institution between January 1999 and March 2017. Clinical and radiological features, histopathology, treatment methods, and prognosis were evaluated.

RESULTS

The mean patient age was 40.3 (range: 7-80)y. The diagnosis was made histopathologically in 91 (91.9%) tumors and on a clinical and radiological basis in 8 (8.1%) tumors. Final diagnoses included idiopathic orbital inflammation (pseudotumor) in 46 (46.5%) lesions, pleomorphic adenoma in 14 (14.1%), adenoid cystic carcinoma in 12 (12.1%), granulomatous inflammation in 10 (10.1%), lymphoma in 5 (5.0%), benign reactive lymphoid hyperplasia in 3 (3.0%), dacryops in 3 (3.0%), carcinoma ex pleomorphic adenoma in 2 (2.0%), adenocarcinoma in 1 (1.0%), dermoid cyst in 1 (1.0%), cavernous hemangioma in 1 (1.0%), and leukemic infiltration in 1 (1.0%). Non-epithelial tumors comprised 64.6% (n=64) of all lacrimal gland tumors, epithelial tumors 32.3% (n=32), dermoid cyst 1% (n=1), cavernous hemangioma 1% (n=1), and leukemic infiltration 1% (n=1). There were in total 78 (78.8%) benign and 21 (21.2%) malignant tumors.

CONCLUSION

Overall, 65% of lacrimal gland tumors were of non-epithelial origin and 32% of epithelial origin. By histopathology and clinical evaluation, 79% of lacrimal gland tumors were benign. The most common lacrimal gland tumors include idiopathic orbital inflammation (46.5%), epithelial (32.3%), and lymphoproliferative (8.1%) lesions.

Epithelial tumors: Growing from within

The growth of epithelial tumors is often governed by cell interactions with the surrounding stroma. Drosophila has been instrumental in identifying the relevant molecular elements mediating these interactions. Of note is the role of the TNF ligand Eiger, released from recruited blood cells, in activating the JNK tumor-promoting pathway in epithelial tumors. JNK drives the transcriptional induction of mitogenic molecules, matrix metalloproteases and systemic signals that lead to tumor growth, tissue invasiveness and malignancy. Here we review our findings on a tumor-intrinsic, Eiger- and stroma-independent mechanism that contributes to the unlimited growth potential of tumors caused either by chromosomal instability or impaired cell polarity. This newly identified mechanism, which was revealed in an experimental condition in which contacts between tumor cells and wild-type epithelial cells were minimized, relies on interactions between functionally distinct tumor cell populations that activate JNK in a cell-autonomous manner. We discuss the impact of cell interaction-based feedback amplification loops on the unlimited growth potential of epithelial tumors. These findings are expected to contribute to the identification of the relevant cell populations and molecular mechanisms to be targeted in drug therapy.

Feedback amplification loop drives malignant growth in epithelial tissues

Interactions between cells bearing oncogenic mutations and the surrounding microenvironment, and cooperation between clonally distinct cell populations, can contribute to the growth and malignancy of epithelial tumors. The genetic techniques available in Drosophila have contributed to identify important roles of the TNF-α ligand Eiger and mitogenic molecules in mediating these interactions during the early steps of tumor formation. Here we unravel the existence of a tumor-intrinsic-and microenvironment-independent-self-reinforcement mechanism that drives tumor initiation and growth in an Eiger-independent manner. This mechanism relies on cell interactions between two functionally distinct cell populations, and we present evidence that these cell populations are not necessarily genetically different. Tumor-specific and cell-autonomous activation of the tumorigenic JNK stress-activated pathway drives the expression of secreted signaling molecules and growth factors to delaminating cells, which nonautonomously promote proliferative growth of the partially transformed epithelial tissue. We present evidence that cross-feeding interactions between delaminating and nondelaminating cells increase each other's sizes and that these interactions can explain the unlimited growth potential of these tumors. Our results will open avenues toward our molecular understanding of those social cell interactions with a relevant function in tumor initiation in humans.

Subsequent malignancies after allogeneic hematopoietic stem cell transplantation

We evaluated 979 patients for the development of post-transplant lymphoproliferative disease (PTLD) and solid malignancies after allogeneic hematopoietic stem cell transplantations (allo-HSCT) as a late complication. We found 15 (1.5%) subsequent malignancies; three of these malignancies were PTLD, and twelve were solid tumors. The median time from allo-HSCT to the development of PTLD was 9 (3-20) months and that from allo-HSCT to the development of solid tumors was 93 (6-316) months. The cumulative incidence of evolving subsequent malignancy in patients was 1.3% (±0.5 SE) at 5 years and 3.9% (±1.2 SE) at 10 years. The cumulative incidence of developing subsequent malignancy in patients with benign hematological diseases as the transplant indication was 7.4%±4.2 SE at 5 years. More subsequent malignancy developed in patients having ≥1 year chronic graft-vs-host disease (GVHD; 3.7% in ≥1 year chronic GVHD and 0.7% in <1 year chronic GVHD patient groups, P=.002). Subsequent epithelial tumor risk was higher in ≥1 year chronic GVHD patients than <1 year (3.7% vs 0.1%, P<.001). In multivariate analysis, benign hematological diseases as transplant indication (RR: 5.6, CI 95%: 1.4-22.3, P=.015) and ≥1 year chronic GVHD (RR: 7.1, 95% CI: 2.3-22.5, P=.001) were associated with the development of subsequent malignancy.

Sparse distribution of gamma/delta T lymphocytes around human epithelial tumors predominantly infiltrated by primed/memory T cells

Evidence from the mouse system has suggested that T lymphocytes accumulating in non-lymphoid tissue, in particular epithelia, may preferentially express the T cell receptor (TCR) gamma delta. In this study, we characterize the T cell receptor alpha beta or gamma delta phenotype of lymphocytes infiltrating human tumors of epithelial origin using monoclonal antibodies (mAb) for immunohistology and flow cytometry on cells extracted by enzyme digestion. This report shows that the majority of CD3+ tumor-infiltrating lymphocytes are TCR alpha beta+ but a small percentage of TCR gamma delta can be clearly defined scattered throughout the tumor tissue with apparently no microanatomical selection. So far there has been little evidence for an accumulation of activated T cells in human tumor tissues as defined by mAb against molecules appearing transiently during the acute phase of activation. Now mAb are available that can identify primed or memory T cells such as mAb UCHL-1 recognizing the CD45RO antigen. Here we show that CD3+ tumor-infiltrating lymphocytes have a statistically significant accumulation of primed T cells, as compared to the autologous peripheral blood lymphocytes, suggesting their immune stimulation by tumor cells.