The Crazy-paving Pattern in Granulomatous Mycosis Fungoides: High-resolution Computed Tomography-Pathological Correlation : Journal of Computer Assisted Tomography

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Thoracic Imaging: Case Report

The Crazy-paving Pattern in Granulomatous Mycosis Fungoides

High-resolution Computed Tomography-Pathological Correlation

Sverzellati, Nicola MD*; Poletti, Venerino MD; Chilosi, Marco MD; Casoni, GianLuca MD; Hansell, David MD§; Zompatori, and Maurizio MD*

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Journal of Computer Assisted Tomography 30(5):p 843-845, September 2006. | DOI: 10.1097/01.rct.0000214269.72180.64
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Abstract

Mycosis fungoides is an unusual histological variant of peripheral T-cell lymphoma that initially manifests as skin disease and later causes peripheral lymphadenopathy and multiple organ involvement. Early recognition of pulmonary involvement of mycosis fungoides is important to start appropriate antineoplastic treatment. However, an early and secure diagnosis is often difficult because of lack of specific clinicoradiological features.

Granulomatous mycosis fungoides is a rare subtype of the disease, and its clinical significance, histopathogenesis, and prognosis remain controversial.1 Although pulmonary involvement occurs in 40% to 60% of cases of mycosis fungoides, the granulomatous variant has rarely been reported. Moreover, thin-section computed tomography (CT) manifestations of granulomatous mycosis fungoides have not previously been correlated with pathological examination.

We report a case of pulmonary granulomatous mycosis fungoides with thin-section CT features comprising nodules with halos of ground-glass attenuation, peripheral consolidations, and a crazy-paving pattern.

The purpose of this report is to discuss a further previously undescribed cause of crazy-paving appearance on thin-section CT and familiarize radiologists with this uncommon entity.

CASE REPORT

A 62-year-old white woman presented with fever (38.0°C), cough, and weakness. She had a history of Hodgkin lymphoma treated successfully 4 years before the current presentation. On physical examination, there was no lymphadenopathy or skin lesions. The peripheral white cell count was 51.800 μL with lymphopenia (1.1%) and eosinophilia (57.6%), and without Sézary cells on peripheral smears. Sputum culture and cytology were negative.

The chest radiograph revealed multiple, bilateral, ill-defined patchy areas of consolidation.

Thin-section CT scan of the lungs showed multiple peripheral areas of patchy consolidation and bilateral nodules with halos of ground-glass attenuation with no zonal predilection. In addition, there was an extensive crazy-paving pattern in the middle lobe (Fig. 1A). There were no enlarged hilar or mediastinal lymph nodes.

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FIGURE 1:
(A) High-resolution computed tomography reveals an area of crazy paving surrounding a peripheral consolidation with patent air bronchogram in the middle lobe. An ill-defined nodule with a halo of ground-glass attenuation is also shown in the right lower lobe. (B) A high-resolution computed tomography scan obtained after treatment shows a reduction in size of the areas of consolidations and nodule; moreover, the crazy-paving pattern resolved almost completely.

Bone marrow biopsy revealed myelodysplasia. A transbronchial lung biopsy from the middle lobe was obtained which showed an interstitial infiltrate consisting of atypical lymphoid cells and intra-alveolar balls of fibrin and buds of intra-alveolar granulation tissue (a histopathologic pattern termed acute fibrinous organizing pneumonia pattern [AFOP])2 (Fig. 2).

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FIGURE 2:
Transbronchial lung biopsy. Interstitial infiltration of atypical lymphoid cells and intra-alveolar balls of fibrinous material with scattered eosinophils (hematoxylin-eosin, magnification 40).

Steroid treatment was started. A repeat thin-section CT scan was obtained 15 days later. A significant improvement with reduction in size of the areas of consolidations and nodules was seen. The crazy-paving pattern had resolved, leaving a small area of ground-glass opacity (Fig. 1B).

An open lung biopsy was considered necessary because of the continuing suspicion of a lymphomatous process. The biopsy of the middle lobe revealed an interstitial infiltrate of atypical lymphoid cells along with poorly formed granulomas. The lymphoid cells appeared to be CD4-positive and CD8- and CD7-negative. The intra-alveolar spaces were normal with no exudates or organizing pneumonia (OP).

DISCUSSION

The key finding of our case is the thin-section CT-histopathologic correlation of crazy-paving pattern in a pulmonary involvement by granulomatous mycosis fungoides. The crazy-paving pattern consists of a network of a smooth linear opacities (representing thickened interlobular septa and intralobular lines) superimposed on a background of ground-glass opacity.3 The crazy-paving appearance is now recognized as a CT manifestation of many diverse entities, and it has recently been reported in association with adult T-cell leukemia or lymphoma, although pathological correlation was not available.4 In our case of granulomatous mycosis fungoides, the area of crazy paving surrounding the peripheral consolidation in the middle lobe corresponded to the histological pattern of AFOP (Figs. 1A and 2).

Beasley et al2 described AFOP as a histological pattern which does not meet the criteria for the patterns of diffuse alveolar damage, OP, or eosinophilic pneumonia. Its dominant finding is the nonuniform presence of intra-alveolar fibrin in the form of fibrin "balls" within the alveolar spaces. AFOP has been observed in a wide spectrum of clinical settings as a pure histological pattern,2 but to our knowledge, its correlation with thin-section CT findings has not been previously described; comparing the thin-section CT- histopathologic findings of our case before and after treatment, we believe that the AFOP pattern, as the OP pattern, could be also considered as a focal nonspecific reaction associated with other processes (the pulmonary involvement by mycosis fungoides in the present case).

It is possible to reconcile the histological pattern of AFOP with the corresponding pattern of crazy paving on thin-section CT scan. The crazy-paving appearance can be caused by alveolar filling processes, interstitial fibrotic processes (mostly those responsible for intralobular interstitial thickening), or a combination of interstitial and alveolar processes; it has been associated with both diffuse alveolar damage and OP.3 Because both intra-alveolar filling process on lung specimen and the crazy-paving pattern on thin-section CT resolved simultaneously, we considered the crazy-paving appearance to correspond to the histological pattern of intra-alveolar fibrin ball formation. Such a correlation is necessary if crazy-paving appearance on thin-section CT is to be attributed to this histological pattern rather than infection, because septicemia and pneumonia are the most frequent causes of death in this disease.5 Although the crazy-paving pattern is not a specific finding, its association with nodules with a surrounding halo of ground-glass attenuation is unusual enough to raise the possibility of a lymphoproliferative disease and, in particular, pulmonary mycosis fungoides.

Our thin-section CT description of diffuse pulmonary involvement by mycosis fungoides differs in some respects from the previous report.6 First, the crazy-paving appearance has not previously been reported; the wedge-shape opacities of the previous case6 corresponded histologically to pulmonary infarctions distal to angiocentric infiltrations of tumor cells, whereas the consolidations in our case were more extensive, with air bronchograms, and were caused by the alveolar occupation by atypical T lymphocytes. Moreover, there were fewer nodules which are more peripheral than the predominantly parahilar nodules reported by Ueda et al.6 This case of granulomatous mycosis fungoides could be different histologically from the previous variant,6 and this fact may explain these thin-section CT variations.

In summary, we describe a new radiographic sign in pulmonary mycosis fungoides, which in our case was indicative of reversible disease. Although further studies with radiological-pathological correlation are required to elucidate this issue, the crazy-paving pattern may serve as a valuable adjunct for radiological evaluation of pulmonary mycosis fungoides.

REFERENCES

1. Gomez-de la Fuente E, Ortiz PL, Vanaclocha F, et al. Aggressive granulomatous mycosis fungoides with clinical pulmonary and thyroid involvement. Br J Dermatol. 2000;142(5):1026-1029.
2. Beasley MB, Franks TJ, Galvin JR, et al. Acute fibrinous and organizing pneumonia: a histological pattern of lung injury and possible variant of diffuse alveolar damage. Arch Pathol Lab Med. 2002;126(9):1064-1070.
3. Johkoh T, Itoh H, Muller NL, et al. Crazy-paving appearance at thin-section CT: spectrum of disease and pathologic findings. Radiology. 1999;211(1):155-160.
4. Okada F, Ando Y, Kondo Y, et al. Thoracic CT findings of adult T-cell leukemia or lymphoma. AJR Am J Roentgenol. 2004;182(3):761-767.
5. Rappaport H, Thomas LB. Mycosis fungoides: the pathology of extracutaneous involvement. Cancer. 1974;34(4):1198-1229.
6. Ueda T, Hosoki N, Isobe K, et al. Diffuse pulmonary involvement by mycosis fungoides: high-resolution computed tomography and pathologic findings. J Thorac Imaging. 2002;17(2):157-159.
Keywords:

computed tomography; mycosis fungoides; lung

© 2006 Lippincott Williams & Wilkins, Inc.