Primary actinomycotic mycetoma of the anterior abdominal wall (a case report).

SK Gupta, VK Shukla, S Khanna 
 Department of Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India., India

Correspondence Address:
S K Gupta
Department of Surgery, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India.
India

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::   Introduction

Mycetoma is a chronic fungal disease of the skin and subcutaneous tissues often invading the muscle fascia and bones, characterised histologically by granuloma formation [8]. The site of involvement varies with the casual agent and the geographical distribution. Eumycotic mycetomas involve the lower extremities in 65-70% of cases followed by the hands, forearm and thorax[7] while infections of the face, neck and abdomen are predominantly actinomycotic[4],[5]. Primary actinomycosis of the anterior abdominal wall is uncommon as is evidenced by sporadic case reports in medical literature[3],[6]. The authors herewith report an uncommon case of primary actinomycotic mycetoma of the anterior abdominal wall.

::   Case report

A 56-year-old female patient belonging to eastern U.P. was admitted with the history of a gradually increasing swelling of one month duration in the lower part of the abdomen. Fifteen days after the appearance of swelling, she developed fever for a week, which responded to antipyretic treatment. There was no previous history of trauma, any oral surgery or of insertion of any intrauterine device. Family histoi), was noncontributory. General examination revealed marked pallor. On local examination, a cystic, fluctuant parietal swelling of 6 x 3 cm size was seen in the hypogastric region. There were no local signs of acute inflammation. Routine laboratory investigations were normal except for ESR, which measured 38 mm at the end of 1 hour (Wintrobe). A presumptive diagnosis of chronic abscess was made and incision and drainage of the swelling was carried out under local anaesthesia. About 100 ml of serosanguinous material was drained out, which showed the characteristic yellowish brown sulfur granules’. However, the swelling persisted with the formation of discharging sinuses, which coalesced to form an ulcerated area. Local signs of acute inflammation appeared and the discharge became seropurulent. Discharge also contained ‘sulfur-granules’ similar to those obtained earlier as was confirmed by microscopic examination. The ulcerated swelling was excised in toto with wide margins of surrounding skin and undeflying rectus abdominis muscle. The peritoneal cavity was free. Primary closure of the wound was done. Post-operative recovery was uneventful. The patient was discharged on the 10th post-operative day.

The macroscopic examination of the specimen revealed a swelling of 6 x 4 x 3 cm consisting of skin, subcutaneous tissue and muscle. The overlying skin was ulcerated irregularly measuring about 3 x 2 cm. Microscopic examination showed that the fungus granules were composed of colonies comprising a tangled mass of branching filaments with terminal club shaped enlargement (ray fungus). The inflammatory cells in the immediate vicinity of the fungus granules were polymorphonuclear lecucocytes. The other inflammatory cells were foam cells, lymphocytes, macrophages and plasma cells. Giant cells were not seen (See Figure:1]) Gram's staining of the section showed irregular Gram positive filaments with terminal Gram negative clubs. They were not acid fast. Exact characterisation of actinomyces could not be done because of nonavailability of culture.

::   Discussion

Mycetoma is a chronic fungal infection of skin and subcutaneous tissues frequent in the tropics[4],[5] and is characterised by the formation of sinuses and fistulous tracts that discharge sero-purulent exudate containing the “sulfur granules”. These granules are the colonies and filaments of the causal agent. Two main groups of the causal agent have been identified, the actinomycotic mycetoma and the eumycotic or maduromycotic mycetoma. It is common in Africa, Mexico, Central America, India, some South American, countries and certain regions of the Orient. The causative organisms vary with the geographical distribution, as does the site of involvement. Eumycotic mycetoma most commonly involves the lower extremities and is seen in rural areas amongst agricultural labourers working under primitive conditions, as trauma especially following repeated inoculation with infected plants heralds the onset of disease[3],[5]. Actinomycosis on the other hand affects the cervicofacial, thoracic and abdominal regions. In abdomen it commonly affects appendix, caecum, stomach, colon and liver[3],[4]. Primary focus is in carious teeth or septic tonsils from where organism is ingested. It has also been reported following insertion of an intrauterine device[1]. The clinical characteristics vary with the causative organisms. It is a relatively painless, locally invasive, indolent tumour like process, which may occur in any part of the body[4]. The hallmarks of a mycetoma are: (1) tumefaction, (2) draining sinuses and (3) presence of microcolonies of the causal organism termed “grains” or “granules” in the pus or tissues - the physical characteristics of these granules depend upon the causal organism. In mycetomas of the actinomycotic group fistulous granuloma formation in skin is greater and they tend to be more inflammatory and invasive. Maduro-mycotic mycetoma on the other hand tend to be more globose and have less inflammatory reaction, granuloma and fistula formation[4],[7]. The diagnosis of mycetoma is established on histopathological examination[2]. It is characterised by a granuloma which consists of a central sup purative zone directly in contact with fungal granules surrounded by histiocytes arranged in a pallisade; a middle region with foreign body giant cells; in the peripheral region of a subacute granuloma with new capillaries and edema are histiocytes, multinucleated giant cells, plasma cells and other cells such as eosinophils. Occasionally small tuberculoid follicles are found in the histiocytic zone. The treatment of mycetorna is difficult and it depends on the causal fungus, degree of invasion and the affected segment. Generally actinomycotic mycetorna responds favourably to treatment than true fungus mycetoma. A trial of conservative surgical intervention such as debridement and drainage should be encouraged along with systemic antifungal therapy. Amputation and wide excision should be used in patients who fall to respond to conservative approach.

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