Epidermoid cyst of the spleen is a rare disease, and relatively few cases were reported by literatures. Most published case reports provided inadequate information on the impact of splenic epidermoid cyst on tumor markers. A 32-year-old woman with a giant splenic epidermoid cyst was reported, for whom the serum concentration of a collection of tumor markers (CA19-9, CEA, CA125, CA242, and CA50) increased abruptly accompanied by left upper abdominal pain for 5 days. After comprehensive preoperative examination and multidisciplinary team discussion, we ruled out any concurrent malignancy and a laparoscopic total splenectomy was performed, during which the splenic cyst spontaneously ruptured unexpectedly. After surgery, the elevated serum tumor marker levels decreased sharply until reaching normal range 3 months later. Learning from the case, we conclude that interval monitoring of serum tumor markers is of critical value for patients with splenic epidermoid cyst. Abrupt elevation of tumor marker levels and abdominal pain may serve as signs of cyst rupture, which is strongly indicative of surgical intervention as soon as possible. Total removal of the splenic cyst is strongly suggested considering the recurrence and malignant potential of the splenic epidermoid cyst.

Gastrointestinal stromal tumors (GIST) are common mesenchymal tumors of the gastrointestinal tract. Some somatic factors have been linked to an increased incidence risk. The diagnostic process for GIST poses difficulties since it bears limited resemblance to ovarian masses, given its manifestation through symptoms like abdominal pain, abdominal mass, fever, weight loss, and loss of appetite. Patients with GIST usually exhibit clinical symptoms and signs of an abdominal mass and chronic pelvic pain might look like an ovarian mass, and diagnosed as GIST on histological examination. A 50-year-old woman presented to the gynecology outpatient department with complaints of an abdominal lump accompanied by pain and decreased appetite persisting for five months, leading to a preliminary diagnosis of an ovarian mass. Further evaluation by histopathological examination was confirmed to be GIST on the final diagnosis.

Fetus-in-fetu (FIF) is a rare congenital anomaly in which a malformed parasitic twin develops within the body of a live fetus or child. Abdominal teratoma, a type of germ cell tumor, can be a great imaging mimicker of FIF and vice-versa, as they both can present as a heterogeneous mass with calcifications and a fat component. Radiological differentiation of these 2 entities should be made because of the difference in surgical planning and treatment options. Features such as visualization of distinct bony vertebral elements and encysted cystic components are the specific features of Fetus in fetu [1]. In contrast, the presence of elevated serum markers can help diagnose teratoma. Here, we report a case of a 5-month-old girl presented with progressive distension of the upper abdomen for the last 2 months, noticed by her mother. Her initial imaging with abdominal X-ray and ultrasonography showed the presence of a large heterogenous solid-cystic mass in the upper abdomen with large elongated calcifications. A provisional diagnosis of teratoma vs FIF was considered. CECT abdomen showed clear identification of osseous structures of the axial and appendicular skeleton within a fat density mass, along with an encapsulated cystic component, strongly suggestive of FIF. Her serum tumor markers were within normal limits. The final diagnosis of FIF was confirmed on Laparotomy and postoperative specimens.

Carbohydrate antigen (CA 19-9) is the most validated marker for both sensitivity and specificity of pancreatic adenocarcinoma used to aid diagnosis of symptomatic patients as well as to evaluate the progression or treatment of disease. Though higher levels of CA 19-9 tend to correlate with neoplastic disease, elevated levels are also often seen in patients with benign gastrointestinal diseases, such as obstructive jaundice and pancreatitis. We present a case of a 74-year-old male who was admitted for abdominal pain and worsening jaundice who was diagnosed with extensive pancreatic necrosis and an underlying invasive pancreatic adenocarcinoma whose serum level of CA 19-9 was found to be extraordinarily high.

This intricate case report details an exceptionally rare incidence of ovarian metastasis originating from a primary lung adenocarcinoma (LUAD). The relative rarity of this metastatic pathway in medical literature indicates significant diagnostic challenges. This patient was initially found to have both the ovarian tumor and lung nodule and they were originally considered independent primary tumors, derived from radiological interpretations and biomarker profiling. Nevertheless, subsequent postoperative histopathological and immunohistochemical staining evaluations identified ovarian tumors as invasive adenocarcinoma metastasized from lung. The lung and ovary tumor both showed marked anaplastic lymphoma kinase gene (ALK) protein expression by immunohistochemistry. The molecular pathologic genetic testing for lung tumor also revealed ALK rearrangement positive. The complexity of this case underscores the essentiality of maintaining a high degree of diagnostic vigilance, particularly when confronting synchronous tumors. In addition, immunohistochemical staining plays an important role in diagnosing the ovarian neoplasm\'s metastatic nature and determining the primary site of metastatic adenocarcinoma. For lung cancer with ovary metastasis patients, the adopting an adaptable treatment approach responsive to evolving diagnostic evidence can improve the accuracy of diagnosis and avoid excessive treatment of patients.

​Extracranial metastasis can occur in intracranial germ cell tumors (GCTs), but it is very rare. Recurrence or metastasis of non-germinomatous germ cell tumors (NGGCTs) is often accompanied by elevated tumor markers. ​Occult extracranial metastases or recurrences with negative markers are often difficult to detect in time, resulting in a very poor prognosis.
A 12-year-old boy was admitted to our institution with dizziness, headache, vomiting, and sleepiness. Magnetic resonance imaging (MRI) showed a pineal mass, accompanied by a significant increase in serum alpha-fetoprotein (AFP). The patient subsequently underwent total removal of the tumor. Pathology revealed that the tumor was a mixed GCT, consisting of mature teratoma, germinoma, and yolk sac tumor. Intracranial GCT achieved complete remission after intensive adjuvant chemotherapy and radiotherapy. Regular follow-up MRI revealed no recurrence of the intracranial tumor and continued monitoring of tumor markers revealed no abnormalities. ​Eight months later, the patient was readmitted due to progressive abdominal pain. Imaging and physical examination revealed abdominal occupation and lymphatic mass in the neck. He received salvage chemotherapy, anti-PD-1 immunotherapy, and palliative chemotherapy, but still developed multiple organ dysfunction syndromes (MODS) due to tumor progression and eventually died after one month.
​This profound case suggests that intracranial NGGCTs may develop occult extracranial malignancy, which can be very severe at the time of clinical symptoms and has an extremely poor prognosis. Therefore, in addition to tumor marker monitoring, regular follow-up with extracranial imaging may be warranted to detect extracranial tumors as early as possible, although perhaps not as frequently as with neuroimaging.

Pseudoprogression is rarely mentioned after radiotherapy except for central nervous system tumors. With the widespread of immunotherapy, the incidence of pseudoprogression of thoracic tumor after radiotherapy is increasing. This study summarized the clinical features of pseudoprogression in 4 patients who had underwent thoracic radiotherapy after and/or followed by immunotherapy. All of them had received chemotherapy and immunotherapy before thoracic radiotherapy. After radiotherapy, pseudoprogression occurred within 3 months after initiation of immune consolidation/rechallenge therapy. At least a 20% increase in the sum of the longest diameter of target lesions were measured on their chest image. During this period, patients\' ECOG PS scores remained stable, specific serum tumor markers did not increase significantly. Treatment strategies did not change after pseudoprogression. The causes of radiographic pseudoprogression in this case series may be attributed to disturbances such as pneumonitis, atelectasis, mucus blockages and infection. In the era of immunotherapy, pseudoprogression of thoracic tumors after chest radiotherapy might become a common phenomenon. It is important for us to identify pseudoprogression based on patient\'s general status, radiological changes, and laboratory tests.

Seminomas and non-seminomas are distinct categories of germ cell tumors arising from the testicles. This case report describes a rare occurrence of a testicular tumor exhibiting histologic characteristics of a seminoma in a 39-year-old male patient who simultaneously has an elevated serum alpha-fetoprotein (AFP). The staging characteristics of this tumor was pT1bNxM0, stage IS. This patient was treated with a right radical orchiectomy and adjuvant chemotherapy with bleomycin, etoposide, and cisplatin. This case report describes the histologic, laboratory, and imaging findings as well as the treatment and surveillance of this patient.

BACKGROUND: The incidence of colon cancer is increasing worldwide. Treatments for colon cancer include surgery and surgery combined with chemotherapy and radiotherapy, but the median survival rate is still poor. Colon cancer most commonly metastasizes to the lymph nodes, lungs, liver, peritoneum, and brain, but breast metastasis is rare. There is no agreement on its treatment.
METHODS: A 23-year-old woman was admitted to our hospital for further treatment with a history of acute abdominal pain, nausea, and vomiting. Her physical examination and computed tomography scan revealed an abdominal tumor. Transverse colectomy was successfully performed. Histopathological examination revealed that the tumor was a mucosecretory adenocarcinoma with signet ring cells. The patient inadvertently found a mass in the outer upper quadrant of the right breast after four cycles of XELOX chemotherapy [oxaliplatin 130 mg/m2, d1, intravenous (iv) drip for 2 h; capecitabine 1000 mg/m2, po, bid, d1-d14]. After discussion with the patient, we performed a lumpectomy and frozen biopsy. The latter revealed that the breast tumor was intestinal metastasis. Genetic testing showed wild-type RAS and BRAF. So we replaced the original chemotherapy with FOLFIRI [irinotecan 180 mg/m2, d1, iv drip for 3-90 min; leucovorin 400 mg/m2, d1, iv drip for 2 h; 5-fluorouracil (5-FU) 400 mg/m2, d1 and 5-FU 1200 mg/(m2 d) × 2 d, continuous iv drip for 46-48 h] + cetuximab (500 mg/m2, d1, iv drip for 2 h). Serum levels of tumor markers returned to normal after several treatment cycles, and there was no evidence of tumor recurrence or metastasis.
CONCLUSIONS: Breast metastasis from colon cancer is rare. Radical breast surgery should be avoided unless needed for palliation. Chemotherapy combined with targeted therapy should be the first choice.

OBJECTIVE: To determine the clinical characteristics, pathological types, tumor markers, treatments, and outcomes of Chinese patients with primary lacrimal sac lymphoma.
METHODS: This case-based retrospective study analyzed 15 Chinese patients with primary lacrimal sac lymphoma. The clinical data collected included gender, age at diagnosis, symptoms, imaging examination results, pathologic diagnosis, pathogen identification, tumor markers, treatments, follow-up, and prognosis. Descriptive statistics were used to characterize the patients. Progression-free survival (PFS) was defined as the time from surgery to the last follow-up, first record of tumor recurrence, or death.
RESULTS: There were 7 males and 8 females with unilateral primary lacrimal sac lymphoma in the left eye (n=6) or right eye (n=9). The initial symptom in 13 patients was epiphora, and 2 patients had redness and swelling in the lacrimal sac area. All patients ultimately developed epiphora, and 12 had masses in the lacrimal sac area. Analysis of preoperative plasma tumor markers indicated 14 patients had elevated homocysteine, 9 had elevated β2-microglobulin, and 2 had elevated lactate dehydrogenase (LDH); 2 patients had elevations of all three markers, and 1 patient had no elevation of any marker. All patients underwent surgical resection and 12 patients received postoperative chemotherapy. The pathological types were DLBCL (n=8), MALT lymphoma (n=5), and NK/T-cell lymphoma, nasal type (n=2). The mean follow-up time was 25.8mo (range: 4-41) and 2 patients died. Seven patients who underwent mass excision combined with dacryocystorhinostomy (DCR) had no postoperative epiphora. Eight patients who only underwent mass excision had varying degrees of postoperative epiphora. Preoperative LDH elevation and NK/T-cell lymphoma, nasal type were associated with poor prognoses.
CONCLUSIONS: Early diagnosis and treatment can lead to a good prognosis for most patients with primary lacrimal sac lymphoma. Mass resection combined with DCR can reduce the occurrence of post-surgical epiphora. The pathology type and tumor marker status are associated with prognosis.