Malignant melanoma of the small bowel presenting with intussusception in a woman: a case report

Comprehensive Literature Review on Melanoma of Unknown Primary Site Triggered by an Intriguing Case Report

Melanoma is one of the most aggressive forms of skin cancer. While most melanomas have a discernible primary site, a small subset, approximately 3.2%, present as a metastatic disease without an identifiable primary origin, a condition known as melanoma of unknown primary (MUP). Unusual cases of primary melanoma have also been previously reported in the respiratory, gastrointestinal, and urogenital tracts. MUP typically is found in lymph nodes, subcutaneous sites, and visceral organs, with hypotheses about its origin including spontaneous primary tumor regression and ectopic melanocytes. MUP presents unique challenges in diagnosis and treatment due to the absence of a detectable primary tumor. Understanding its genetic and molecular features, epidemiology, prognostic factors, and treatment options is crucial for optimizing patient care and outcomes in this subset of melanoma patients. We conducted an extensive literature review triggered by a case report of a patient with suspected MUP. A 51-year-old woman was transferred from another hospital where an incision was performed for a suspected superinfected hematoma of the left thigh. Since the patient showed high leukocytosis and redness and swelling of the thigh, local debridement, drainage, and excisional biopsy of the tumor mass were performed in our unit in the emergency setting, and the tumor was taken for histopathology evaluation. Intraoperatively, the mass appeared nonspecific. The permanent histopathology report established a diagnosis of melanoma, with tumor proliferation also involving lymphoid tissue, and despite broad clinical and imagistic assessments, the primary melanoma could not be identified. Clinicians must be aware of the varied clinical manifestations of malignant melanoma, especially in cases of occult melanoma where the primary site is not evident.

Small bowel melanoma causing obstruction: A case report and a literature review

INTRODUCTION

Primary small bowel melanoma (PSBM) is a rare form of melanoma that originates from the intestinal mucosa. It is typically asymptomatic; however, it can present with non-specific symptoms, which pose challenges in accurately diagnosing the condition. In rare cases, it may manifest as small bowel obstruction, further adding challenges with diagnosis and management.

CASE PRESENTATION

A 57-year-old male presented to the hospital with complaints of chronic constipation, abdominal pain, and abdominal enlargement. Computed tomography (CT) scan revealed thickening of the jejunum wall, while endoscopy and biopsy revealed nothing. During surgery, surgeons identified and excised a jejunal mass. Subsequent pathological analysis confirmed the diagnosis of melanoma, and post-surgical examination failed to identify primary cutaneous melanoma.

DISCUSSION

PSBM is a rare and aggressive tumor often misdiagnosed due to non-specific symptoms and challenging imaging interpretations. Obstruction and intussusception are uncommon presentations. Surgical resection offers symptom control and improved prognosis, but achieving negative margins can be challenging. Early recognition and diagnosis are crucial for optimal management.

CONCLUSION

The lack of data in the literature presents challenges in identifying and selecting the optimal approach for managing PSBM. Physicians should increase their awareness of this specific type of tumor to facilitate early-stage diagnosis and provide appropriate care for patients.

Primary Malignant Melanoma of the Small Intestine Presenting with Peritonitis: A Case Report

Malignant melanoma of the small intestine is mostly a metastatic tumor of other primary lesions, especially of skin origin. Primary malignant melanoma of the small intestine is very uncommon. The clinical presentation is usually nonspecific, thus leading to late diagnosis. We report a 42-year-old man who presented to the emergency department of Imam-Reza Hospital with symptoms and signs of peritonitis and was a candidate for emergency laparotomy and enterectomy. The medical and family history were unremarkable. A bulky mass was seen 190 cm away from the Treitz band, and a diagnosis of malignant melanoma was confirmed by histologic and immunohistochemical study. Further clinical examination revealed no primary tumor elsewhere, so the diagnosis of primary small intestinal melanoma was concluded. Although metastatic malignant melanoma in the GI tract is common, the primary one is a very rare entity. The diagnosis could be challenging because a thorough investigation is needed to rule out the possible initial origin.

Multiple gastrointestinal melanoma causing small bowel intussusception

A 61-year-old gentleman presented with small bowel intussusception from small bowel melanoma intussusceptum. He complains of intermittent abdominal distension but no history of intestinal obstruction. Apart from this, he was also symptomatic anemia which required repeated transfusion for the past few months. The contrast-enhanced computed tomography of the abdomen shows an omental mass with small bowel intussusception. He then underwent an exploratory laparotomy with segmental resection of the affected segment. Histopathological examination confirmed primary gastrointestinal melanoma. Multiple small bowel malignant melanoma is a rare disease. It remains a controversial diagnosis as it may be a primary or metastasis from an unidentified or regressed primary cutaneous melanoma. Prompt surgical intervention enables us to obtain tissue diagnosis, prevent complete intestinal obstruction and strategize the goals of treatment for the patient.

Small bowel obstruction caused by hemorrhagic metastatic melanoma: case report and literature review

Melanoma is one of the most common cancers and causes of death from skin cancer. It is also one of the most common malignancies to metastasize to the gastrointestinal tract. However, the incidence of gastrointestinal metastases from unknown primary cutaneous melanoma is reported to be 4–9%. Despite advances in diagnostic techniques, only 1.5–4.4% of metastases to the gastrointestinal tract are detected before death. We report a patient with no prior history of melanoma who presented with both gastrointestinal hemorrhage and small bowel obstruction. Diagnostic laparoscopy, followed by small bowel resection, was performed after a red blood cell radionuclide scan showed active hemorrhage. Pathologic examination confirmed metastatic melanoma of the jejunum. Additional small bowel resections were required for recurrent gastrointestinal bleeding, confirming two additional metastases. A review of the literature on small intestinal melanoma causing hemorrhage and obstruction is discussed.

Primary jejunal amelanotic melanoma: case report and review of literature

Intussusception more commonly occurs in pediatrics but is a rare cause of bowel obstruction and gastrointestinal bleeding in adults. It typically occurs in adults due to a malignancy, which serves as a pathologic lead point. We present a case of a 64-year-old female with nausea, vomiting, and melena who was found to have intussusception associated with a primary jejunal amelanotic melanoma. Both intussusception and primary small bowel melanomas are rare causes of obstruction and bleeding. Intussusception occurring as a result of a primary small bowel amelanotic melanoma is exceedingly rare with very few reported cases. We provide a case report and review of the literature.

Metastatic melanoma causing recurrent intussusception and perforation of small bowel: case reports and literature review

Aim:

To present cases of recurred jejuno-jejunal intussusception and jejunal perforation due to melanoma.

Materials & methods:

Case 1: A 43-year-old male under treatment for malignant melanoma was presented with abdominal pain and distention. Ten centimeter intussuscepted jejunum was resected. Second exploration was done due to failure to pass gas and stool. The reintussusception was detected and resection of reintussuscepted jejunum was performed. Case 2: A 63-year-old male was presented with abdominal pain. Abdomen computed tomography showed free air in the abdomen suggesting intestinal perforations. Perforated area at 80 cm in the jejunum sutured.

Conclusion:

We present the seemingly first report of reintussusception of resected segment in a very short time. Surgeons should be aware of both intussusception and perforation in metastatic melanoma.