A rare case of Calcified Mediastinal Lymphadenopathy Due to anal Adenocarcinoma Metastasis

Abstract

Introduction: Anal cancers constitute 1.5% of all gastrointestinal malignancies. Intrathoracic lymph nodal calcification is thought to be sequelae of prior granulomatous diseases, however, it is a known predictor of metastasis from various primaries. We describe a case of anal adenocarcinoma with multiple calcified metastatic mediastinal lymphadenopathies. 

Case Details:A 43-year-old female presented with bleeding per rectum and chest pain for 1 month. Digital per rectal examination revealed thickened anal wall. Contrast-enhanced computed tomography(CECT) of the pelvis showed irregular circumferential wall thickening in the anal canal. CECT of the thorax showed multiple calcified mediastinal lymphadenopathies. Serum calcium level was normal. Proctoscopy-guided biopsy from the anal canal was reported as adenocarcinoma. PET-CT (Positron Emission Tomography-computed tomography) showed uptake in the proximal anal canal and mediastinal lymph nodes. Endobronchial ultrasound-guided fine needle aspiration was reported as metastatic adenocarcinoma. Finally, it was found to be a case of well-differentiated adenocarcinoma of the anal canal with multiple calcified metastatic mediastinal lymphadenopathies.

Discussion: Metastasis in anal carcinoma is seen only in 10% of cases, of which the most common is in the liver and lungs. Calcified mediastinal lymph nodes are manifestations of previous granulomatous infection but are rarely due to metastasis from mucin-producing adenocarcinomas. Interestingly in our case, after the biopsy confirmation of anal adenocarcinoma, PET-CT showed mediastinal nodal uptake rather than other solid organs or pelvic or inguinal lymph nodes. There are very few reports of metastases of anal cancer to mediastinal nodes in the literature. We did a thorough web search and as far as we know, this is the first case report on calcified metastatic mediastinal lymphadenopathies from anal adenocarcinoma. CONCLUSION: If calcified mediastinal lymph nodes are found in the CECT thorax, apart from benign conditions, metastasis from the lower gastrointestinal tract malignancies should be in the working differentials and hence pathological examination of calcified nodes becomes mandatory.