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Appendiceal mucinous neoplasms comprise less than 1% of all appendicectomy specimens.¹ Depending upon cytological atypia and invasion, they are further divided into low grade appendiceal mucinous neoplasm (LAMN), high grade appendiceal mucinous neoplasm (HAMN) and mucinous adenocarcinoma according to Peritoneal surface oncology group international (PSOGI).² LAMN coexisting with tuberculosis is a rare entity as well as incidental finding. However, there is no case report of coexistence of LAMN with tuberculosis.

55 year old male presented to surgery OPD with chief complaints of pain abdomen associated with vomiting for last 2 days. Pain was acute in onset with severe intensity and non-radiating. Abdominal examination showed tenderness in right lower quadrant and marked rigidity. On chest x-ray, air under right dome of diaphragm noted. Investigations revealed Hb- 12.3gm/dl, total leukocyte count was increased (12.5x109/l) and differential leukocyte count showed neutrophilia (82%). Platelets, liver function tests, serum electrolytes and kidney function tests were normal. Clinical diagnosis of perforation peritonitis was made. Patient was operated and ileo-caecal resection with end ileostomy was done and sent for histopathological examination.

Gross examination revealed resected segment of intestine comprising of ileum, caecum and appendix. Grossly, a perforation identified and mucosa over ileum exhibited transverse ulcers and appendix was dilated and filled with mucin. Histopathology examination showed numerous epithelioid cell granulomas cuffed by lymphocytes with central caseous necrosis and Langhan’s giant cell reaction throughout the ileum and appendiceal wall. Sections of appendix also demonstrated proliferation of mucinous epithelium and acellular mucin perforating the wall but not extending below the muscularis propria.  We did the ZN stain for AFB demonstration however, it was negative. Therefore, histopathological diagnosis of low-grade mucinous neoplasm of appendix with granulomatous inflammation consistent with tuberculosis was reported. Patient started ATT and after that his condition got improved. 

Extrapulmonary tuberculosis accounts for approximately 15-20% of TB cases in immunocompetent host.  Among them, incidence of GIT TB is approximately 1-3%.³ It most frequently involves the ileo-caecal region followed by colon, appendix, duodenum and stomach in the decreasing order of frequency.⁴ Coexistence of tuberculosis and neoplasm on the same site of GIT remains a topic of debate since many years.

Literature documented few cases of concomitant occurrence of TB and mucinous carcinoma of GIT, commonly involves caecum and colon. Studies showed that association of carcinoma and tuberculosis may be coincidence or one disease might be responsible for the pathogenesis of other one.⁵ However, some authors have proposed the various pathogenetic mechanisms to suggest the coexistence of both. As we know the various inflammatory bowel disorders are the precursors of GIT malignancy, they lead to chronic mucosal damage in turn it initiates the process of carcinogenesis in the form of metaplasia, dysplasia then further lead to neoplastic change. It has been postulated that TB may be precursor of malignancy either due to chronic ulceration in the form of repeated insults as erosions followed by ulceration and consequently results in regeneration or by lowering immunity.^4,5

Similarly, carcinomas disturb host immune system and make the person susceptible to acquire the active tubercular infection either by impairment of cell mediated immunity or by local mechanism through the disruption of the integrity of mucosal barriers.⁵ Furthermore, malignancy might lead to activation of dormant tubercular lesion by releasing the various tumor peptides or antigens that allow the proliferation of tuberculous organism or endogenous reactivation.⁵

There are some controversies regarding the classification of mucinous neoplasm of appendix.  According to PSOGI, AMN divides into LAMN and HAMN depending upon degree of cytological atypia and complexity of architecture. LAMN is defined as low grade cytology and any of the following features - loss of muscularis mucosae, fibrosis of submucosa, flattened epithelial growth, pushing invasion, dissection of acellular mucin in the wall, mucin and/or neoplastic cells outside of the appendix or circumferential involvement of the mucosa by a mucin-rich epithelium involving at least 1 segment of the appendix. LAMN is preoperatively diagnosed as acute appendicitis or appendiceal perforation and often diagnosed late.² Furthermore, diagnosis of LAMN is of utmost importance for treatment purposes as according to literature if diagnosis is LAMN then only appendicectomy is done or debulking surgery has to be done in cases of advanced stages like pseudomyxoma peritonei.

Tuberculosis of appendix with LAMN is a rare manifestation and an etiopathological relationship between them is a diagnostic dilemma. Here, this case report highlights the importance of histopathological examination in case of obstructive lesion of appendix. However, the definitive causeeffect relation between these two pathologies still remains unclear and has to be further evaluated by future studies.