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Clinical Meetings at RH Year 2004

2004 - Things can be more benign than what they appear to be

Dr WL Law, Department of Medicine, Queen Elizabeth Hospital

Case 1
Case history
A 43-year-old male chronic smoker and drinker, was suffering from epilepsy and putting on dilantin and epilim since 1990. He complained of 3-month history of weight loss, malaise and anorexia. He was afebrile with stable vital sign on admission. Body weight was 47 kg (with height 175 cm) and there was no finger clubbing or palpable lymph node. On chest auscultation, breath sounds were decreased over left lower zone. Other examination was unremarkable. Complete blood picture showed mildly elevated WCC 9.3 units (Neu 6.3 Lym 1.3 Eos 0.1) with increased ESR 83 units. Renal and liver function tests were normal except hypoalbuminaemia (alb 24 units). Calcium and LDH level were within normal range. PO2 and PCO2 were 13 and 4.6 kPa (Room Air) respectively. Dilantin and epilim levels were below therapeutic range. Urine RBC and albumin were negative. Sputum AFB, culture and cytology were also negative. CXR (PA and left lateral) showed a left lower lobe shadow. CT thorax with contrast showed 2 tumour masses at left lower lobe with invasion into pericardium and pleura at lung base. Pericardial and pleural effusions were noted. There was also a 0.8 cm mediastinal lymph node at AP window regions (Figure 1). Echocardiogram showed moderate pericardial effusion at apex of the heart.



FOB showed no endobronchial lesion. Bronchial aspirate for AFB and cytology was negative. Transbronchial biopsy showed no evidence of malignancy. Left VATS was done and pleural and pericardial biopsies were obtained which showed only fibrosis and chronic inflammation, with no evidence of malignancy. Subsequently, thoracotomy with left lower lobectomy was done. Histology showed that the tumour-like lesion was a chronic abscess with areas of large collections of neutrophils, accompanied by destruction of lung tissue, fibro-granulation tissue formation and chronic inflammatory cells infiltration. Sulphur granules were identified. Gram-staining showed Gram-positive filamentous bacteria. The final diagnosis was Pulmonary actinomycosis. He was given 4-weeks course of intravenous penicillin (6 mega-units q4h) and discharged with oral penicillin but then, he defaulted follow-up.

Discussion
Actinomyces are Gram-positive, non-spore forming, predominantly anaerobic higher prokaryotic bacteria, which were first described by Bollinger in 1877, in which one of the species (A. Bovis) caused suppurative swelling of cattle jaws. I Six out of 14 species of Actinomycosis are commensals of human oropharynx, GI tract and female genital tract. Less than 50% cases are culture positive due to inadequate culture
technique, prior antibiotics and bacterial overgrowth. 2 Sulphur granules are pathological hallmark representing conglomeration of bacteria that form only in vitro. Microscopically, they are round basophilic masses with radiating arrangement of eosinophilic clubs. Sulphur granules are also seen in Nocardiosis, Chromomycosis and Botryomycosis etc. Cervicofacial region is the most frequently affected area (eg lumpy jaw). Pulmonary
actinomycosis is rare, constituted around 15%of cases of actinomycosis. 2 It usually happens in fourth to fifth decade with male predominance. Poor dental hygiene, alcoholics and epilepsy are major risk factors. The pathogenesis involves aspiration of oropharyngeal or GI secretions into the respiratory tract, causing atelectasis and pneumonitis followed by chronic necrosis, fibrosis and cavitation. 3 Classically, pulmonary actinomycosis presents with prominent chest pain andcutaneous fistulas discharging sulphur granules (Bates and Cruickshank 1957). Radiological manifestations include lung masses, pleural effusion, solitary pulmonary nodule, miliary shadow, endobronchial lesion not detected on CXR. Tranbronchial biopsy is seldom successful in providing enough diagnostic material. 4 Majority of cases had definite diagnosis made only after open surgery, as most cases initially presented as a malignant tumour, as in our case. Eighteen to 24 mega-units of intravenous penicillin per day for 2-6 weeks, followed by 6-12 months oral penicillin are the standard treatment. 2 Tetracycline and erythromycin are good alternatives. Some studies advocated some shorter and convenient treatment regimes including 4 weeks IV Tienam, 5 3 weeks daily dose ceftriaxone. 6 Surgery is indicated only for medical treatment failure, extensive disease, sinus tract or fistula formation, and drainage of large abscess.

Case 2
Case history
The patient was a non-smoker and non-drinker working in a garment factory. She had history of uterine tumour with operation done in 1984. She presented with vague chest discomfort for one month. Private chest X-ray showed multiple lung shadows (Figure 2). Physical examination was unremarkable except for the abdominal surgical scar. There were no palpable lymph nodes, breast lumps or thyroid nodules.



Complete blood picture, ESR, renal and liver function, autoimmune and tumour markers including AFP, CEA, CA 125 were all normal. Sputum examination was unremarkable. Chest X-ray showed multiple lung nodules. FOB showed no endobronchial lesion. Transbronchial biopsy (RB6, RLL) performed under XR screening showed no evidence of malignancy. Whole body CT-PET scan (Figure 3) showed numerous hypometabolic nodular lesions up to 3.6cm in size are noted in both lungs (maximum uptake SOY 1.4). There were hypometabolic right ovarian cyst and meningioma too. CT-guided FNAC (anterior aspect of RUL mass) showed no malignant cells. YATS with right lower lobe lung biopsy was performed. Histology showed nodules composing of numerous interlacing bundles of bland-looking smooth muscle cells with entrapped respiratory epithelium.



The final diagnosis was Benign Metastasizing Leiomyoma (BML). She was referred to Gynaecology clinic and monthly injection ofLHRH analogue (Decapeptyl 3.75mg) was started. CXR showed regression of lung nodules.

Discussion
BML is histologically benign smooth muscle tumor, which originates from a uterine fibroid. 7 It is rare with less than 60 documented cases since first case in 1939. Affected areas include lung, pelvic and retroperitoneal lymph nodes, omentum, lYC,right atrium and even limb muscle. 8 It usually affects women between age of 36 and 65 with uterine fibroid or history of hysterectomy for fibroid. Most are asymptomatic with CXR taken for other reasons. It often presents as multiple lung nodules. Clinical course varies from chronic indolent illness to rapidly progressive disease leading to respiratory failure and death. From the literature, only 3 cases eventually died of respiratory failure so far. Three hypotheses explained the 'metastatic' nature of the disease: 1) as a low grade leiomyosarcoma, 2) implantation and proliferation of smooth muscle cells after embolization of an intravenous leiomyomatosis, 3) multifocal but independent, autochronus proliferation of smooth muscle cells. 9 Estrogen and progesterone receptors are found on BML and it explains why BML grows in response to hormonal level. 9 This is the rationale behind the use of hormonal therapy, which includes progesterone, LHRH analogue or even hysterectomy and oophorectomy (surgical menopause).

References
  1. David F. Bennhoff. Actinomycosis:diagnostic and therapeutic considerations and a review of 32 cases. Laryngoscope 1984; 94: 1198-1217.
  2. Russo TA. Agents of actinomycosis. Mandell GL. Principles and Practice of Infectious Disease. 5th edn. New York. Churchchill Livingstone, 1995;pp 2645-2654.
  3. Mabeza GF, Macfarlane J. Pulmonary actinomycosis. Eur Respir J 2003;21 :545-551.
  4. Kinnear WJM, MacFarlane JT. A survey of thoracic actinomycosis. Respir Med 1990;84:57-59.
  5. Yew WW, Wong PCW, Wong CF, Chau CR. Use of imipenem in the treatment of thoracic actinomycosis. Clin Infect Dis 1994;19:983-984.
  6. Skoutelis A, Petrochilos J, Bassaris H. Successful treatment ofthoracic actinomycosis with ceftriazone. Clin Infect Dis 1994;19:161-162.
  7. Goyle KK, Moore DF Jr, Garrett C, Goyle V. Benign metastasizing leiomyomatosis:case report and review. American Journal of Clinical Oncology 2003;26:473-476.
  8. Parenti DJ, Morley TF, Giudice JC. Benign metastasizing leiomyoma, a case report and review of literature. Respiration 1992;56:347-350.
  9. Gal AA, Brooks JS, Pietra GG. Leiomyomatosis neoplasms of the lung:a clinical, histologic, and immunohistochemical study. Modern Pathology 1989;2:209-216.
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