Download `Fish-tank` granuloma: a diagnostic dilemma

Internal Medicine Journal 39 (2009) 338–340
I M AG E S I N M E D I C I N E
‘Fish-tank’ granuloma: a diagnostic dilemma
A 45-year-old man complained of a 3-month history of
multiple, mildly painful, non-tender, purple-red nodules
on the dorsum of his right hand (Fig. 1). They started as
small superficial lesions days after he had worked on his
boat, followed by swelling, reddening and nodularity.
Further nodules had grown on the volar surface of the
right forearm (Fig. 2).
He was afebrile and routine laboratory studies were
normal; there was no palpable lymphadenopathy. Biopsied tissue was sent for routine histologic analysis and
staining for fungi and acid-fast bacilli, the results of both
being non-diagnostic (Fig. 3a,b).
Intracutaneous testing with tuberculin purified protein
derivative was positive at 48–72 h.
Culture from secretion of the lesion at 32°C grew a
mycobacterium identified as Mycobacterium marinum.
Figure 1 Multiple erythematous nodules on the dorsal of the right hand
and of the third finger.
A 2-month course of oral clarithromycin (500 mg
twice daily) resolved his symptoms, with no relapses.
M. marinum is a free-living mycobacterium that causes
disease in poikilothermic water animals and occasionally
in humans through contaminated water.1,2 Approximately 50% of infections with identifiable exposures are
aquarium-related with the remainder related to fish and
marine occupations or activities.
Infection with M. marinum most commonly manifests
with erythematous, papulonodular or plaque-like lesions
of the extremities, tending to occur over prominences,
such as a finger, hand or knee, the incubation period
varying from 2 to 6 weeks after the traumatic inoculation. It is usually limited to the skin, less commonly
extending to involve deeper structures, such as joints and
tendons. Dissemination is rare.1,3
Figure 2 Sporotrichoid nodule of the forearm along the line of lymphatic
drainage.
Figure 3 (A) Inflammatory infiltrates in the
mid-portion of the dermis and beneath
the acanthotic epidermis (haematoxylin and
eosin stain, original magnification ¥20). (B)
High-magnification photomicrograph of the
granulomatous infiltrates shows lymphocytes, histiocytes, neutrophils and giant cells
(haematoxylin and eosin stain, original magnification ¥100).
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© 2009 The Authors
Journal compilation © 2009 Royal Australasian College of Physicians
Images in Medicine
Superficial M. marinum infections may be treated with
watchful waiting, surgical excision or with a single oral
agent, such as clarithromycin, minocycline, cotrimoxazole, rifampicin or ethambutol.4
Acknowledgement
The Authors thank Dr Bruno Barreca (Department of
Social Territorial Medicine, Section of Dermatology,
University of Messina) for his contribution in providing
digital imaging.
Received 7 November 2007; accepted 12 December 2007.
References
1 Huminer D, Pitlik SD, Block C, Kaufman L, Amit S,
Rosenfeld JB. Aquarium-borne Mycobacterium marinum
skin infection. Report of a case and review of the
literature. Arch Dermatol 1986; 122: 698–703.
2 Beran V, Matlova L, Dvorska L, Svastova P, Pavlik I.
Distribution of mycobacteria in clinically healthy
ornamental fish and their aquarium environment. J Fish
Dis 2006; 29: 383–93.
3 Gkrania-Klotsas E, Lewer AM. A husband and wife with
left hand rashes. Lancet Infect Dis 2005; 5: 802.
4 Gluckman SJ. Mycobacterium marinum. Clin Dermatol
1995; 13: 273–6.
doi:10.1111/j.1445-5994.2009.01923.x
C. Guarneri and S. P. Cannavò
Department of Social Territorial Medicine, Section of Dermatology,
University of Messina, Messina, Italy
An unexpected pericardial tumour
A previously well 41-year-old man, presenting with
unexplained weight loss, accelerated exertional dyspnoea
and chest tightness over 18 months, was found to have a
large mediastinal mass on echocardiography at a peripheral hospital and was referred to our institution for
further investigation. A chest X-ray demonstrated only
mild transverse cardiomegaly. Inflammatory markers,
full blood examination and biochemistry were unremarkable, there was no lymphadenopathy and abdominal computed tomography (CT) failed to reveal any
pathology.
Thoracic CT (Fig. 1a) and transthoracic echocardiography demonstrated a large pericardial mass but were
inconclusive with respect to cardiac infiltration, therefore
cardiac magnetic resonance imaging (CMR) was performed. CMR imaging (Fig. 1b–d) at the basal short axis
level confirmed a large inferior pericardial soft tissue
mass with mild compression of the right ventricle and a
small pericardial effusion. The mass did not invade the
cardiac wall and appeared to have a clear line of separation from the myocardium. Exploratory sternotomy and
cardiac biopsy were performed to assess resectability, but
there was no identifiable surgical plane to remove the
mass. Frozen section microscopic examination showed a
malignant epithelioid tumour. Immunohistochemistry
with S-100 confirmed the diagnosis of metastatic
© 2009 The Authors
Journal compilation © 2009 Royal Australasian College of Physicians
melanoma (Fig. 2). A thorough skin examination failed
to identify any primary lesion.
The prognosis for melanoma with systemic metastasis
is almost universally fatal, with a median survival of
6–8 months. In up to 8% of cases a primary site cannot be
identified.1 Australia has the highest incidence of melanoma in the world.2
Received 5 September 2007; accepted 24 October 2007.
doi:10.1111/j.1445-5994.2009.01922.x
1
H. B. Pfluger, A. Murugasu2 and A. J. Taylor1,3
1
Heart Centre and 2Department of Anatomical Pathology, The
Alfred Hospital and 3Baker Heart Research Institute, Melbourne,
Victoria, Australia
References
1 Cormier JN, Xing Y, Feng L, Huang X, Davidson L,
Gershenwald JE et al. Metastatic melanoma to lymph
nodes in patients with unknown primary sites. Cancer
2006; 106: 2012–20.
2 Coory M, Baade P, Aitken J, Smithers M, McLeod GR,
Ring I. Trends for in situ and invasive melanoma in
Queensland, Australia, 1982–2002. Cancer Causes Control
2006; 17: 21–7.
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