Salmonella paratyphi A infection presenting as breast abscess

Abstract

Salmonella in a breast abscess is uncommon, and Salmonella paratyphi A causing breast abscess is a rare entity. It has been reported post immunosuppression. We report here a 35-year-old woman with breast abscess caused by S. paratyphi A without obvious enteric fever-like symptoms. The case was managed with combined surgical and medical approach to treat the aetiology and focal infection.

Background

Salmonella can cause enteric fever, septicaemia without localisation, focal disease (with or without bacteraemia), gastroenteritis or chronic carrier state. Salmonella is less likely to cause breast abscess, hence, case reports are rare. We present here the case of 35-year-old woman with chronic breast abscess caused by Salmonella paratyphi A.

Case presentation

A 35-year-old woman came with complaints of left breast lump of 3 weeks duration. The lump was asymptomatic. There was no history of pain, fever, trauma, nipple retraction or discharging sinus. The patient was non-lactating, and there was no sudden increase in the size of the lump. She was a known case of idiopathic thrombocytopaenic purpura and was on steroids for the same. There was no history of tuberculosis (TB) or TB contact.

The patient was haemodynamically stable. Systemic examination was normal. Lump was present in the lower inner quadrant of left breast, measuring 3×3×2 cm. Minimal seropurulent discharge was expressed on pressure from the nipple. The lump was non-tender. Same-side axilla was normal. The opposite breast and axilla were normal.

Investigations

Sonography was suggestive of multiple small intercommunicating pockets of collection, predominantly liquefied, largest measuring 1.6 cm×3.1 cm×2.5 cm with approximate volume of 7 cc.

The patient underwent incision and drainage. The whitish semisolid material, which was drained, was sent for bacterial culture and sensitivity testing. Antibiotics tested included: Ampicillin, Augmentin, azithromycin, cotrimoxazole, Chloramphenicol, meropenem, imipenem, Ceftriaxone, Amikacin, ciprofloxacin and piperacillin-tazobactam. The isolate was sensitive to Ampicillin, cotrimoxazole, Chloramphenicol, Ceftriaxone and ciprofloxacin. The isolate was resistant to azithromycin and nalidixic acid.

Specimen was sent for Gene Xpert, for which, CB-NAAT GeneXpert IV (Manufactured by Cephid, Sunnyvale, California, USA) was used. Also, the same was sent for acid fast bacterial smear and culture. Wall scrapings were sent for histopathology. S. paratyphi A was recovered from the sample enriched in glucose broth, which was confirmed by serotyping. The antisera used was Salmonella polyvalent antisera A–G (manufactured by Denka Seiken Co, Tokyo, Japan). Widal test was positive for Salmonella. Blood culture was negative for Salmonella in our case. Microbiological methods used were bacterial culture by conventional microbiological methods and antibiotic sensitivity by Kirby-Bauer disk diffusion method using ready-made antibiotic discs (HiMedia Laboratories, Mumbai, India). Blood culture system used was BD BACTEC blood culture system (manufactured by Becton, Dickinson and Company, Sparks, New Jersey, USA). Acid-fast bacilli were not seen, and GeneXpert was negative. Histopathology report was suggestive of ‘Duct ectasia in the background of fibrocystic changes’.

Differential diagnosis

Diagnosis of bacterial breast abscess, tubercular breast abscess or breast tumour was made.

Treatment

The patient was managed with combined medical and surgical approach. Incision and drainage was done. After recovery of S. paratyphi A from the discharge and widal positivity, injectable intravenous ceftriaxone was given for 5 days.

Outcome and follow-up

Clinically and radiologically, the abscess resolved completely after 6 weeks.

Discussion

Breast abscess typically presents as tense, red, shining, fluctuating swelling. However, in this case of chronic breast abscess, these symptoms were masked. Salmonella is a rare cause of breast abscess.¹ It is interesting to note that most of the reported cases have been from India, where salmonellosis is endemic.² Incidence of Salmonella breast abscess is 0.9% in typhoid infection.³ The first reported case of breast abscess was by Thayer and Hazen in 1907, in a young woman presenting with breast abscess.⁴ In our case, it was probably a case of focal infection with S. paratyphi, or it could be a case of chronic carrier, manifesting as a breast abscess. Most common Salmonella reported to cause breast abscess is S. typhi.⁵

In immunocompromised states, seeding of the bacteria in distant sites may occur, causing focal localised infection.^{1 6 7}

In our case, the patient had idiopathic thrombocytopaenic purpura and was on steroid therapy, which may explain the low immunity. The positive widal test indicated a carrier state, and the low immunity due to steroids may have led to breast abscess.

Learning points.

• Salmonella breast abscess is uncommon, and Salmonella paratyphi A is one of the rare entities but has to be kept in mind.

• Every breast abscess should be sent for culture and sensitivity for aetiological diagnosis.

• When Salmonella is noted in the breast abscess, blood culture and widal test have to be carried out to facilitate appropriate diagnosis and management.

• It is a standard practice to inoculate the sample in blood agar and MacConkey agar. However, inoculation in glucose broth, which is an enrichment medium, helps in the copious growth of organism, which may have been missed otherwise.